6.18.39-rc1 review

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mahesh Vaidya <[email protected]>

commit 5ef4bac02189bee0b7c170e352d7a38e13fe9678 upstream.

altera_pcie_irq_teardown() calls irq_dispose_mapping() on pcie->irq. However, pcie->irq is the parent IRQ returned by platform_get_irq(), not the mapping created by Altera INTx irq_domain.

The Altera driver only sets the chained handler on the parent IRQ. It should detach that handler during teardown, but it should not dispose the parent IRQ mapping, which belongs to the parent interrupt controller's irq_domain.

Drop irq_dispose_mapping(pcie->irq) from the teardown path.

Note that during irqchip remove(), the child IRQs should've disposed. But since the chained handler itself is removed, there is no way the stale child IRQs (if exists) could fire. So it is safe here.

---
 drivers/pci/controller/pcie-altera.c |    1 -
 1 file changed, 1 deletion(-)

@@ -868,7 +868,6 @@ static void altera_pcie_irq_teardown(str
 {
 	irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
 	irq_domain_remove(pcie->irq_domain);
-	irq_dispose_mapping(pcie->irq);
 }
 
 static int altera_pcie_parse_dt(struct altera_pcie *pcie)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mahesh Vaidya <[email protected]>

commit 7a94138caeb27f3c49c1dbd93bf422098925bb28 upstream.

The chained IRQ handler is set during probe, but is only removed during the driver remove(). If pci_host_probe() fails, the handler and INTx IRQ domain remain set even though the devm-managed host bridge storage containing struct altera_pcie will be released, leaving the handler with a stale data pointer.

Interrupts are also enabled before pci_host_probe() is called. If probe fails after that point, the controller interrupt source should be disabled before the chained handler and INTx domain are removed.

So set the chained handler only after the INTx domain has been created. Disable controller interrupts during IRQ teardown, and tear the IRQ setup down if pci_host_probe() fails.

---
 drivers/pci/controller/pcie-altera.c |   35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

@@ -864,8 +864,23 @@ static int altera_pcie_init_irq_domain(s
 	return 0;
 }
 
+static void altera_pcie_disable_irq(struct altera_pcie *pcie)
+{
+	if (pcie->pcie_data->version == ALTERA_PCIE_V1 ||
+	    pcie->pcie_data->version == ALTERA_PCIE_V2) {
+		/* Disable all P2A interrupts */
+		cra_writel(pcie, 0, P2A_INT_ENABLE);
+	} else if (pcie->pcie_data->version == ALTERA_PCIE_V3) {
+		/* Disable port-level interrupts (CFG_AER, etc.) */
+		writel(0, pcie->hip_base +
+			  pcie->pcie_data->port_conf_offset +
+			  pcie->pcie_data->port_irq_enable_offset);
+	}
+}
+
 static void altera_pcie_irq_teardown(struct altera_pcie *pcie)
 {
+	altera_pcie_disable_irq(pcie);
 	irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
 	irq_domain_remove(pcie->irq_domain);
 }

@@ -890,7 +905,6 @@ static int altera_pcie_parse_dt(struct a
 	if (pcie->irq < 0)
 		return pcie->irq;
 
-	irq_set_chained_handler_and_data(pcie->irq, pcie->pcie_data->ops->rp_isr, pcie);
 	return 0;
 }
 

@@ -1019,6 +1033,14 @@ static int altera_pcie_probe(struct plat
 		return ret;
 	}
 
+	/*
+	 * The chained handler uses pcie->irq_domain, so set it only after the
+	 * INTx domain has been created.
+	 */
+	irq_set_chained_handler_and_data(pcie->irq,
+					 pcie->pcie_data->ops->rp_isr,
+					 pcie);
+
 	if (pcie->pcie_data->version == ALTERA_PCIE_V1 ||
 	    pcie->pcie_data->version == ALTERA_PCIE_V2) {
 		/* clear all interrupts */

@@ -1036,7 +1058,16 @@ static int altera_pcie_probe(struct plat
 	bridge->busnr = pcie->root_bus_nr;
 	bridge->ops = &altera_pcie_ops;
 
-	return pci_host_probe(bridge);
+	ret = pci_host_probe(bridge);
+	if (ret)
+		goto err_teardown_irq;
+
+	return 0;
+
+err_teardown_irq:
+	altera_pcie_irq_teardown(pcie);
+
+	return ret;
 }
 
 static void altera_pcie_remove(struct platform_device *pdev)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Maciej W. Rozycki <[email protected]>

commit 72780f7964684939d7d2f69c348876213b184484 upstream.

Discard Vendor:Device ID matching in the PCIe failed link retraining quirk and ignore the link status for the removal of the 2.5GT/s speed clamp, whether applied by the quirk itself or the firmware earlier on. Revert to the original target link speed if this final link retraining has failed.

This is so that link training noise in hot-plug scenarios does not make a link remain clamped to the 2.5GT/s speed where an event race has led the quirk to apply the speed clamp for one device, only to leave it in place for a subsequent device to be plugged in.

Refer to the Link Capabilities register directly for the maximum link speed determination so as to streamline backporting.

---
 drivers/pci/quirks.c |   51 ++++++++++++++++++---------------------------------
 1 file changed, 18 insertions(+), 33 deletions(-)

@@ -79,11 +79,10 @@ static bool pcie_lbms_seen(struct pci_de
  * Restrict the speed to 2.5GT/s then with the Target Link Speed field,
  * request a retrain and check the result.
  *
- * If this turns out successful and we know by the Vendor:Device ID it is
- * safe to do so, then lift the restriction, letting the devices negotiate
- * a higher speed.  Also check for a similar 2.5GT/s speed restriction the
- * firmware may have already arranged and lift it with ports that already
- * report their data link being up.
+ * If this turns out successful, or where a 2.5GT/s speed restriction has
+ * been previously arranged by the firmware and the port reports its link
+ * already being up, lift the restriction, in a hope it is safe to do so,
+ * letting the devices negotiate a higher speed.
  *
  * Otherwise revert the speed to the original setting and request a retrain
  * again to remove any residual state, ignoring the result as it's supposed

@@ -94,52 +93,38 @@ static bool pcie_lbms_seen(struct pci_de
  */
 int pcie_failed_link_retrain(struct pci_dev *dev)
 {
-	static const struct pci_device_id ids[] = {
-		{ PCI_VDEVICE(ASMEDIA, 0x2824) }, /* ASMedia ASM2824 */
-		{}
-	};
-	u16 lnksta, lnkctl2;
+	u16 lnksta, lnkctl2, oldlnkctl2;
 	int ret = -ENOTTY;
+	u32 lnkcap;
 
 	if (!pci_is_pcie(dev) || !pcie_downstream_port(dev) ||
 	    !pcie_cap_has_lnkctl2(dev) || !dev->link_active_reporting)
 		return ret;
 
 	pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
+	pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &oldlnkctl2);
 	if (!(lnksta & PCI_EXP_LNKSTA_DLLLA) && pcie_lbms_seen(dev, lnksta)) {
-		u16 oldlnkctl2;
-
 		pci_info(dev, "broken device, retraining non-functional downstream link at 2.5GT/s\n");
-
-		pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &oldlnkctl2);
 		ret = pcie_set_target_speed(dev, PCIE_SPEED_2_5GT, false);
-		if (ret) {
-			pci_info(dev, "retraining failed\n");
-			pcie_set_target_speed(dev, PCIE_LNKCTL2_TLS2SPEED(oldlnkctl2),
-					      true);
-			return ret;
-		}
-
-		pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
+		if (ret)
+			goto err;
 	}
 
 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
-
-	if ((lnksta & PCI_EXP_LNKSTA_DLLLA) &&
-	    (lnkctl2 & PCI_EXP_LNKCTL2_TLS) == PCI_EXP_LNKCTL2_TLS_2_5GT &&
-	    pci_match_id(ids, dev)) {
-		u32 lnkcap;
-
+	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
+	if ((lnkctl2 & PCI_EXP_LNKCTL2_TLS) == PCI_EXP_LNKCTL2_TLS_2_5GT &&
+	    (lnkcap & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {
 		pci_info(dev, "removing 2.5GT/s downstream link speed restriction\n");
-		pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
 		ret = pcie_set_target_speed(dev, PCIE_LNKCAP_SLS2SPEED(lnkcap), false);
-		if (ret) {
-			pci_info(dev, "retraining failed\n");
-			return ret;
-		}
+		if (ret)
+			goto err;
 	}
 
 	return ret;
+err:
+	pci_info(dev, "retraining failed\n");
+	pcie_set_target_speed(dev, PCIE_LNKCTL2_TLS2SPEED(oldlnkctl2), true);
+	return ret;
 }
 
 static ktime_t fixup_debug_start(struct pci_dev *dev,

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ratheesh Kannoth <[email protected]>

commit fda8749ba73638f5bbca3ffb39bc6861eb3b23fa upstream.

pci_host_common_init() is used by several generic ECAM host drivers. After PCI core changes around pci_flags and preserve_config, these hosts no longer opted into full bus number reassignment the way they did before, which broke enumeration of devices on a Marvell CN106XX board.

When PCI_PROBE_ONLY is not set, add PCI_REASSIGN_ALL_BUS so pci_scan_bridge_extend() takes the reassignment path: bus numbers can be assigned from firmware EA data (e.g. pci_ea_fixed_busnrs()). Skip the flag in probe-only mode so existing assignments are not overridden.

---
 drivers/pci/controller/pci-host-common.c |    4 ++++
 1 file changed, 4 insertions(+)

@@ -72,6 +72,10 @@ int pci_host_common_init(struct platform
 	if (IS_ERR(cfg))
 		return PTR_ERR(cfg);
 
+	/* Do not reassign bus numbers if probe only */
+	if (!pci_has_flag(PCI_PROBE_ONLY))
+		pci_add_flags(PCI_REASSIGN_ALL_BUS);
+
 	bridge->sysdata = cfg;
 	bridge->ops = (struct pci_ops *)&ops->pci_ops;
 	bridge->enable_device = ops->enable_device;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Richard Zhu <[email protected]>

commit aad953fb4eed0df5486cd54ccad80ac197678e01 upstream.

The IMX6SX_GPR12_PCIE_TEST_POWERDOWN bit does not control the PCIe reference clock on i.MX6SX. Instead, it is part of i.MX6SX PCIe core reset sequence.

Move the IMX6SX_GPR12_PCIE_TEST_POWERDOWN assertion/deassertion into the core reset functions to properly reflect its purpose. Remove the .enable_ref_clk() callback for i.MX6SX since it was incorrectly manipulating this bit.

---
 drivers/pci/controller/dwc/pci-imx6.c |   12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

@@ -659,14 +659,6 @@ static int imx_pcie_attach_pd(struct dev
 	return 0;
 }
 
-static int imx6sx_pcie_enable_ref_clk(struct imx_pcie *imx_pcie, bool enable)
-{
-	regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
-			   IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
-			   enable ? 0 : IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
-	return 0;
-}
-
 static int imx6q_pcie_enable_ref_clk(struct imx_pcie *imx_pcie, bool enable)
 {
 	if (enable) {

@@ -765,6 +757,9 @@ static int imx6sx_pcie_core_reset(struct
 	if (assert)
 		regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
 				IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
+	else
+		regmap_clear_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				  IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
 
 	/* Force PCIe PHY reset */
 	regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR5, IMX6SX_GPR5_PCIE_BTNRST_RESET,

@@ -1852,7 +1847,6 @@ static const struct imx_pcie_drvdata drv
 		.mode_off[0] = IOMUXC_GPR12,
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
 		.init_phy = imx6sx_pcie_init_phy,
-		.enable_ref_clk = imx6sx_pcie_enable_ref_clk,
 		.core_reset = imx6sx_pcie_core_reset,
 		.ops = &imx_pcie_host_ops,
 	},

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Manivannan Sadhasivam <[email protected]>

commit f865a57896bd92d7662eb2818d8f48872e2cbbc7 upstream.

When mtk_pcie_enable_port() fails, mtk_pcie_port_free() removes the port from pcie->ports and frees the port structure. However, the IRQ domains set up earlier by mtk_pcie_init_irq_domain() are never freed.

Fix this by refactoring mtk_pcie_irq_teardown() into a per-port helper, mtk_pcie_irq_teardown_port(), and calling it from mtk_pcie_setup() when mtk_pcie_enable_port() fails. Since the IRQ teardown must only happen in the probe error path (during resume, child devices may have active MSI mappings and the NOIRQ context prohibits sleeping locks), mtk_pcie_enable_port() is changed to return an error code so callers can distinguish the two paths and act accordingly.

This issue was reported by Sashiko while reviewing the EcoNet EN7528 SoC support series.

---
 drivers/pci/controller/pcie-mediatek.c |   63 ++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 23 deletions(-)

@@ -519,23 +519,27 @@ static void mtk_pcie_enable_msi(struct m
 	writel(val, port->base + PCIE_INT_MASK);
 }
 
-static void mtk_pcie_irq_teardown(struct mtk_pcie *pcie)
+static void mtk_pcie_irq_teardown_port(struct mtk_pcie_port *port)
 {
-	struct mtk_pcie_port *port, *tmp;
+	irq_set_chained_handler_and_data(port->irq, NULL, NULL);
 
-	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
-		irq_set_chained_handler_and_data(port->irq, NULL, NULL);
+	if (port->irq_domain)
+		irq_domain_remove(port->irq_domain);
 
-		if (port->irq_domain)
-			irq_domain_remove(port->irq_domain);
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		if (port->inner_domain)
+			irq_domain_remove(port->inner_domain);
+	}
 
-		if (IS_ENABLED(CONFIG_PCI_MSI)) {
-			if (port->inner_domain)
-				irq_domain_remove(port->inner_domain);
-		}
+	irq_dispose_mapping(port->irq);
+}
 
-		irq_dispose_mapping(port->irq);
-	}
+static void mtk_pcie_irq_teardown(struct mtk_pcie *pcie)
+{
+	struct mtk_pcie_port *port, *tmp;
+
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+		mtk_pcie_irq_teardown_port(port);
 }
 
 static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,

@@ -823,7 +827,7 @@ static int mtk_pcie_startup_port(struct
 	return 0;
 }
 
-static void mtk_pcie_enable_port(struct mtk_pcie_port *port)
+static int mtk_pcie_enable_port(struct mtk_pcie_port *port)
 {
 	struct mtk_pcie *pcie = port->pcie;
 	struct device *dev = pcie->dev;

@@ -832,7 +836,7 @@ static void mtk_pcie_enable_port(struct
 	err = clk_prepare_enable(port->sys_ck);
 	if (err) {
 		dev_err(dev, "failed to enable sys_ck%d clock\n", port->slot);
-		goto err_sys_clk;
+		return err;
 	}
 
 	err = clk_prepare_enable(port->ahb_ck);

@@ -880,11 +884,15 @@ static void mtk_pcie_enable_port(struct
 		goto err_phy_on;
 	}
 
-	if (!pcie->soc->startup(port))
-		return;
+	err = pcie->soc->startup(port);
+	if (err) {
+		dev_info(dev, "Port%d link down\n", port->slot);
+		goto err_soc_startup;
+	}
 
-	dev_info(dev, "Port%d link down\n", port->slot);
+	return 0;
 
+err_soc_startup:
 	phy_power_off(port->phy);
 err_phy_on:
 	phy_exit(port->phy);

@@ -900,8 +908,8 @@ err_aux_clk:
 	clk_disable_unprepare(port->ahb_ck);
 err_ahb_clk:
 	clk_disable_unprepare(port->sys_ck);
-err_sys_clk:
-	mtk_pcie_port_free(port);
+
+	return err;
 }
 
 static int mtk_pcie_parse_port(struct mtk_pcie *pcie,

@@ -1067,8 +1075,13 @@ static int mtk_pcie_setup(struct mtk_pci
 		return err;
 
 	/* enable each port, and then check link status */
-	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
-		mtk_pcie_enable_port(port);
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+		err = mtk_pcie_enable_port(port);
+		if (err) {
+			mtk_pcie_irq_teardown_port(port);
+			mtk_pcie_port_free(port);
+		}
+	}
 
 	/* power down PCIe subsys if slots are all empty (link down) */
 	if (list_empty(&pcie->ports))

@@ -1167,14 +1180,18 @@ static int mtk_pcie_resume_noirq(struct
 {
 	struct mtk_pcie *pcie = dev_get_drvdata(dev);
 	struct mtk_pcie_port *port, *tmp;
+	int err;
 
 	if (list_empty(&pcie->ports))
 		return 0;
 
 	clk_prepare_enable(pcie->free_ck);
 
-	list_for_each_entry_safe(port, tmp, &pcie->ports, list)
-		mtk_pcie_enable_port(port);
+	list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+		err = mtk_pcie_enable_port(port);
+		if (err)
+			mtk_pcie_port_free(port);
+	}
 
 	/* In case of EP was removed while system suspend. */
 	if (list_empty(&pcie->ports))

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Yadu M G <[email protected]>

commit e0779713a1e2f891aeec53e629dbbd33f423c629 upstream.

A lockdep warning is observed during boot on a Qcom firmware-managed platform:

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator.
...

  Call trace:
   register_lock_class+0x128/0x4d8
   __lock_acquire+0x110/0x1db0
   lock_acquire+0x278/0x3d8
   _raw_spin_lock_irq+0x6c/0xc0
   dw_pcie_irq_domain_alloc+0x48/0x190
   irq_domain_alloc_irqs_parent+0x2c/0x48
   msi_domain_alloc+0x90/0x160
  ...

dw_pcie_irq_domain_alloc() takes pp->lock while allocating MSI interrupts. pp->lock is normally initialized by dw_pcie_host_init(), but Qcom firmware-managed hosts use the ECAM init path instead:

pci_host_common_ecam_create()

    pci_ecam_create()
      qcom_pcie_ecam_host_init()
        dw_pcie_msi_host_init()
          dw_pcie_allocate_domains()

That path constructs a fresh struct dw_pcie_rp and calls dw_pcie_msi_host_init() directly, without going through dw_pcie_host_init(). As a result, pp->lock was not initialized, which triggers the warning.

Initialize pp->lock in qcom_pcie_ecam_host_init() before registering the MSI domains so the firmware-managed ECAM path matches the normal DWC host initialization sequence.

---
 drivers/pci/controller/dwc/pcie-qcom.c |    6 ++++++
 1 file changed, 6 insertions(+)

@@ -1626,6 +1626,12 @@ static int qcom_pcie_ecam_host_init(stru
 	pci->dbi_base = cfg->win;
 	pp->num_vectors = MSI_DEF_NUM_VECTORS;
 
+	/*
+	 * dw_pcie_msi_host_init() is called directly here, bypassing
+	 * dw_pcie_host_init() where pp->lock is normally initialized.
+	 */
+	raw_spin_lock_init(&pp->lock);
+
 	ret = dw_pcie_msi_host_init(pp);
 	if (ret)
 		return ret;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marco Nenciarini <[email protected]>

commit f34f1712229d71ce4286440fef12526fd4590b37 upstream.

sriov_restore_vf_rebar_state() uses the VF Resizable BAR Control register to decide how many VF BARs to restore (nbars) and which VF BAR each iteration addresses (bar_idx). bar_idx indexes into dev->sriov->barsz[], which has only PCI_SRIOV_NUM_BARS (6) entries.

When a device does not respond, config reads typically return PCI_ERROR_RESPONSE (~0). Both fields are 3 bits wide, so nbars and bar_idx both evaluate to 7. The barsz[] access then goes out of bounds. UBSAN reports this as:

  UBSAN: array-index-out-of-bounds in drivers/pci/iov.c:948:51 index 7 is out of range for type 'resource_size_t [6]'

Observed on an NVIDIA RTX PRO 1000 GPU (GB207GLM) that stopped responding during a failed GC6 power state exit. The subsequent pci_restore_state() invoked sriov_restore_vf_rebar_state() while config reads returned 0xffffffff, triggering the splat.

Bail out if any VF Resizable BAR Control read returns PCI_ERROR_RESPONSE. No further VF BARs are touched, which is safe because a config read that returns PCI_ERROR_RESPONSE indicates the device is unreachable and restoration is pointless. This mirrors the guard in pci_restore_rebar_state().

---
 drivers/pci/iov.c |    6 ++++++
 1 file changed, 6 insertions(+)

@@ -938,12 +938,18 @@ static void sriov_restore_vf_rebar_state
 		return;
 
 	pci_read_config_dword(dev, pos + PCI_VF_REBAR_CTRL, &ctrl);
+	if (PCI_POSSIBLE_ERROR(ctrl))
+		return;
+
 	nbars = FIELD_GET(PCI_VF_REBAR_CTRL_NBAR_MASK, ctrl);
 
 	for (i = 0; i < nbars; i++, pos += 8) {
 		int bar_idx, size;
 
 		pci_read_config_dword(dev, pos + PCI_VF_REBAR_CTRL, &ctrl);
+		if (PCI_POSSIBLE_ERROR(ctrl))
+			return;
+
 		bar_idx = FIELD_GET(PCI_VF_REBAR_CTRL_BAR_IDX, ctrl);
 		size = pci_rebar_bytes_to_size(dev->sriov->barsz[bar_idx]);
 		ctrl &= ~PCI_VF_REBAR_CTRL_BAR_SIZE;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Bommarito <[email protected]>

commit 8bc4d43bccbd60efe85d0a44d5bf41762f2f0c30 upstream.

Commit 51e547e8c89c ("tcp: Free TCP-AO/TCP-MD5 info/keys without RCU") removed the call_rcu() callback from tcp_ao_destroy_sock(), arguing that "the destruction of info/keys is delayed until the socket destructor" and therefore "no one can discover it anymore".

That argument does not hold for the call site in tcp_connect() (net/ipv4/tcp_output.c:4327-4332). At that point the socket is in TCP_SYN_SENT, has already been inserted into the inet ehash by inet_hash_connect() in tcp_v4_connect(), and is therefore very much
discoverable: any softirq running tcp_v4_rcv() on another CPU can take the socket out of the ehash, walk into tcp_inbound_hash(), and load tp->ao_info via implicit RCU before bh_lock_sock_nested() is taken on the destroying CPU.

The reader path then enters __tcp_ao_do_lookup() (net/ipv4/tcp_ao.c:208) which re-loads tp->ao_info via rcu_dereference_check(); the re-load can still observe the (about-to-be-freed) pointer because there is no synchronize_rcu() between rcu_assign_pointer(tp->ao_info, NULL) and tcp_ao_info_free() in tcp_ao_destroy_sock(). The captured pointer is then walked at line 223:

	hlist_for_each_entry_rcu(key, &ao->head, node, ...)

The writer's synchronous kfree() is free to complete between the line 218 re-fetch and the line 223 hlist iteration. The slab is reused (or simply LIST_POISON1-stamped if not yet reused) and the iteration walks attacker-controlled or poison memory in softirq context.

Reproducer (no debug shim, stock x86_64 v7.1-rc2 SMP+KASAN, QEMU+KVM):
an unprivileged uid=1000 process inside CLONE_NEWUSER|CLONE_NEWNET installs TCP_MD5SIG + TCP_AO_ADD_KEY on a TCP socket, sprays forged TCP-AO segments toward its eventual 4-tuple via raw sockets, then calls connect(). The md5-wins reconciliation in tcp_connect() fires tcp_ao_destroy_sock(); the softirq backlog reader on the loopback NAPI path crashes on the freed ao->head.first walk:

  Oops: general protection fault, probably for non-canonical
    address 0xfbd59c000000002f
  KASAN: maybe wild-memory-access in range
    [0xdead000000000178-0xdead00000000017f]
  CPU: 0 UID: 1000 PID: 100 Comm: repro_userns
  RIP: 0010:__tcp_ao_do_lookup+0x107/0x1c0
  Call Trace: <IRQ>
    __tcp_ao_do_lookup+0x107/0x1c0
    tcp_ao_inbound_lookup.constprop.0+0x12a/0x200
    tcp_inbound_ao_hash+0x5ea/0x1520
    tcp_inbound_hash+0x7ce/0x1240
    tcp_v4_rcv+0x1e7a/0x3e10
    ...

Restore the RCU grace period: re-add struct rcu_head to tcp_ao_info and replace the synchronous tcp_ao_info_free() with a call_rcu() callback. Readers that captured tp->ao_info before rcu_assign_pointer NULLed it now see the object remain valid until rcu_read_unlock(). With the patch applied the reproducer runs cleanly for 2000 iterations on the same kernel build.

---
 include/net/tcp_ao.h |    1 +
 net/ipv4/tcp_ao.c    |    5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

@@ -130,6 +130,7 @@ struct tcp_ao_info {
 	u32			snd_sne;
 	u32			rcv_sne;
 	refcount_t		refcnt;		/* Protects twsk destruction */
+	struct rcu_head		rcu;
 };
 
 #ifdef CONFIG_TCP_MD5SIG

@@ -270,8 +270,9 @@ static void tcp_ao_key_free_rcu(struct r
 	kfree_sensitive(key);
 }
 
-static void tcp_ao_info_free(struct tcp_ao_info *ao)
+static void tcp_ao_info_free_rcu(struct rcu_head *head)
 {
+	struct tcp_ao_info *ao = container_of(head, struct tcp_ao_info, rcu);
 	struct tcp_ao_key *key;
 	struct hlist_node *n;
 

@@ -311,7 +312,7 @@ void tcp_ao_destroy_sock(struct sock *sk
 
 	if (!twsk)
 		tcp_ao_sk_omem_free(sk, ao);
-	tcp_ao_info_free(ao);
+	call_rcu(&ao->rcu, tcp_ao_info_free_rcu);
 }
 
 void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: SeongJae Park <[email protected]>

commit 35d4a3cf70a855b50e53189ac2f8463e20a02046 upstream.

Fix three issues in damon_hot_score() that comes from wrong handling of extreme (zero or too high) monitoring intervals user setup.

When the user sets sampling interval zero, damon_max_nr_accesses(), which is called from damon_hot_score(), causes a divide-by-zero. Needless to say, it is a problem.

When the user sets the aggregation interval zero, the function returns zero. It is wrong, since the real maximum nr_acceses in the setup should be one. Worse yet, it can cause another divide-by-zero from its caller, damon_hot_score(), since it uses damon_max_nr_accesses() return value as a denominator.

When the user sets the aggregation interval very high, damon_hot_score() could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return value is used as an index to the regions_score_histogram array, which is DAMOS_MAX_SCORE+1 size, it causes out of bounds array access.

The issues can be relatively easily reproduced like below. The sysfs write permission is required, though.

    # ./damo start --damos_action lru_prio --damos_quota_space 100M \
            --damos_quota_interval 1s
    # cd /sys/kernel/mm/damon/admin/kdamonds/0
    # echo 0 > contexts/0/monitoring_attrs/intervals/sample_us
    # echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us
    # echo commit > state
    # dmesg
    [...]
    [  131.329762] Oops: divide error: 0000 [#1] SMP NOPTI
    [...]
    [  131.336089] RIP: 0010:damon_hot_score+0x27/0xd0
    [...]

Fix the divide-by-zero intervals problems by explicitly handling the zero intervals in damon_max_nr_accesses(). Fix the out-of-bound array access by applying [0, DAMOS_MAX_SCORE] bounds before returning from damon_hot_score().

The issue was discovered [1] by Sashiko.

---
 include/linux/damon.h |    8 ++++++--
 mm/damon/ops-common.c |    1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

@@ -939,9 +939,13 @@ static inline bool damon_target_has_pid(
 
 static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs)
 {
-	/* {aggr,sample}_interval are unsigned long, hence could overflow */
-	return min(attrs->aggr_interval / attrs->sample_interval,
+	unsigned long sample_interval;
+	unsigned long max_nr_accesses;
+
+	sample_interval = attrs->sample_interval ? : 1;
+	max_nr_accesses = min(attrs->aggr_interval / sample_interval,
 			(unsigned long)UINT_MAX);
+	return max_nr_accesses ? : 1;
 }
 
 

@@ -128,6 +128,7 @@ int damon_hot_score(struct damon_ctx *c,
 	 * Transform it to fit in [0, DAMOS_MAX_SCORE]
 	 */
 	hotness = hotness * DAMOS_MAX_SCORE / DAMON_MAX_SUBSCORE;
+	hotness = max(min(hotness, DAMOS_MAX_SCORE), 0);
 
 	return hotness;
 }

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Xiang Mei <[email protected]>

commit 7cd9103283b26b917360ec99d7d2f2d761bcf1ab upstream.

The release path of ip_set_dump_do() and ip_set_dump_done() read inst->ip_set_list via ip_set_ref_netlink(), a plain rcu_dereference_raw() of the array pointer. These run from netlink_recvmsg() without the nfnl mutex and without an RCU read-side critical section.

A concurrent ip_set_create() can grow the array: it publishes the new array, calls synchronize_net() and then kvfree()s the old one. Since the dump paths read the array outside any RCU reader, synchronize_net() does not wait for them and the old array can be freed while they still index into it, causing a use-after-free.

The dumped set itself stays pinned via set->ref_netlink, so only the array load needs protecting. Take rcu_read_lock() around it, matching ip_set_get_byname() and __ip_set_put_byindex().

  BUG: KASAN: slab-use-after-free in ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
  Read of size 8 at addr ffff88800b5c4018 by task exploit/150
  Call Trace:
   ...
   kasan_report (mm/kasan/report.c:595)
   ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1697)
   netlink_dump (net/netlink/af_netlink.c:2325)
   netlink_recvmsg (net/netlink/af_netlink.c:1976)
   sock_recvmsg (net/socket.c:1159)
   __sys_recvfrom (net/socket.c:2315)
   ...
  Oops: general protection fault, probably for non-canonical address ... KASAN NOPTI
  KASAN: maybe wild-memory-access in range [0x02d6...d0-0x02d6...d7]
  RIP: 0010:ip_set_dump_do (net/netfilter/ipset/ip_set_core.c:1698)
  Kernel panic - not syncing: Fatal exception

---
 net/netfilter/ipset/ip_set_core.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

@@ -1480,7 +1480,11 @@ ip_set_dump_done(struct netlink_callback
 		struct ip_set_net *inst =
 			(struct ip_set_net *)cb->args[IPSET_CB_NET];
 		ip_set_id_t index = (ip_set_id_t)cb->args[IPSET_CB_INDEX];
-		struct ip_set *set = ip_set_ref_netlink(inst, index);
+		struct ip_set *set;
+
+		rcu_read_lock();
+		set = ip_set_ref_netlink(inst, index);
+		rcu_read_unlock();
 
 		if (set->variant->uref)
 			set->variant->uref(set, cb, false);

@@ -1685,7 +1689,9 @@ next_set:
 release_refcount:
 	/* If there was an error or set is done, release set */
 	if (ret || !cb->args[IPSET_CB_ARG0]) {
+		rcu_read_lock();
 		set = ip_set_ref_netlink(inst, index);
+		rcu_read_unlock();
 		if (set->variant->uref)
 			set->variant->uref(set, cb, false);
 		pr_debug("release set %s\n", set->name);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ammar Faizi <[email protected]>

commit f7d380fb525c13bdd114369a1979c80c346e6abc upstream.

Unbinding a virtio balloon device:

echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind

triggers a NULL pointer dereference. The dmesg says:

    BUG: kernel NULL pointer dereference, address: 0000000000000008
    [...]
    RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0
    Call Trace:
    <TASK>
    vp_del_vqs+0x121/0x230
    remove_common+0x135/0x150
    virtballoon_remove+0xee/0x100
    virtio_dev_remove+0x3b/0x80
    device_release_driver_internal+0x187/0x2c0
    unbind_store+0xb9/0xe0
    kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180
    vfs_write+0x2a9/0x3b0
    ksys_write+0x5c/0xd0
    do_syscall_64+0x54/0x230
    entry_SYSCALL_64_after_hwframe+0x29/0x31
    [...]
    </TASK>

The virtio_balloon device registers 5 queues (inflate, deflate, stats, free_page, reporting) but only the first two are unconditional. The stats, free_page and reporting queues are each conditional on their respective feature bits. When any of these features are absent, the corresponding vqs_info entry has name == NULL, creating holes in the array.

The root cause is an indexing mismatch introduced when vq info storage was changed to be passed as an argument. vp_find_vqs_msix() and vp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i' is the caller's sparse array index. However, the virtqueue itself gets vq->index assigned from queue_idx, a dense index that skips NULL entries. When holes exist, 'i' and queue_idx diverge. Later, vp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense index into the sparsely-populated array, and hits NULL.

Fix this by storing info at vp_dev->vqs[queue_idx] instead of vp_dev->vqs[i], so the store index matches the lookup index (vq->index). Apply the fix to both the MSIX and INTX paths.

Message-Id: <[email protected]>

---
 drivers/virtio/virtio_pci_common.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -426,10 +426,11 @@ static int vp_find_vqs_msix(struct virti
 			vqs[i] = NULL;
 			continue;
 		}
-		vqs[i] = vp_find_one_vq_msix(vdev, queue_idx++, vqi->callback,
+		vqs[i] = vp_find_one_vq_msix(vdev, queue_idx, vqi->callback,
 					     vqi->name, vqi->ctx, false,
 					     &allocated_vectors, vector_policy,
-					     &vp_dev->vqs[i]);
+					     &vp_dev->vqs[queue_idx]);
+		queue_idx++;
 		if (IS_ERR(vqs[i])) {
 			err = PTR_ERR(vqs[i]);
 			goto error_find;

@@ -488,9 +489,10 @@ static int vp_find_vqs_intx(struct virti
 			vqs[i] = NULL;
 			continue;
 		}
-		vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback,
+		vqs[i] = vp_setup_vq(vdev, queue_idx, vqi->callback,
 				     vqi->name, vqi->ctx,
-				     VIRTIO_MSI_NO_VECTOR, &vp_dev->vqs[i]);
+				     VIRTIO_MSI_NO_VECTOR, &vp_dev->vqs[queue_idx]);
+		queue_idx++;
 		if (IS_ERR(vqs[i])) {
 			err = PTR_ERR(vqs[i]);
 			goto out_del_vqs;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <[email protected]>

commit c687bc35694698ec4c7f92bf929c3d659f0cecb8 upstream.

Driver core expects devices to be allocated dynamically and complains loudly when a device that lacks a release function is freed.

Use __root_device_register() to allocate and register the root device instead of open coding using a static device.

Note that root_device_register(), which also creates a link to the module, cannot be used as the device is registered when parsing the module parameters which happens before the module kobject has been set up.

Message-ID: <[email protected]>

---
 drivers/virtio/virtio_mmio.c |   26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

@@ -662,9 +662,7 @@ static void virtio_mmio_remove(struct pl
 
 #if defined(CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES)
 
-static struct device vm_cmdline_parent = {
-	.init_name = "virtio-mmio-cmdline",
-};
+static struct device *vm_cmdline_parent;
 
 static int vm_cmdline_parent_registered;
 static int vm_cmdline_id;

@@ -672,7 +670,6 @@ static int vm_cmdline_id;
 static int vm_cmdline_set(const char *device,
 		const struct kernel_param *kp)
 {
-	int err;
 	struct resource resources[2] = {};
 	char *str;
 	long long base, size;

@@ -704,11 +701,10 @@ static int vm_cmdline_set(const char *de
 	resources[1].start = resources[1].end = irq;
 
 	if (!vm_cmdline_parent_registered) {
-		err = device_register(&vm_cmdline_parent);
-		if (err) {
-			put_device(&vm_cmdline_parent);
+		vm_cmdline_parent = __root_device_register("virtio-mmio-cmdline", NULL);
+		if (IS_ERR(vm_cmdline_parent)) {
 			pr_err("Failed to register parent device!\n");
-			return err;
+			return PTR_ERR(vm_cmdline_parent);
 		}
 		vm_cmdline_parent_registered = 1;
 	}

@@ -719,7 +715,7 @@ static int vm_cmdline_set(const char *de
 		       (unsigned long long)resources[0].end,
 		       (int)resources[1].start);
 
-	pdev = platform_device_register_resndata(&vm_cmdline_parent,
+	pdev = platform_device_register_resndata(vm_cmdline_parent,
 			"virtio-mmio", vm_cmdline_id++,
 			resources, ARRAY_SIZE(resources), NULL, 0);
 

@@ -743,8 +739,12 @@ static int vm_cmdline_get_device(struct
 static int vm_cmdline_get(char *buffer, const struct kernel_param *kp)
 {
 	buffer[0] = '\0';
-	device_for_each_child(&vm_cmdline_parent, buffer,
-			vm_cmdline_get_device);
+
+	if (vm_cmdline_parent_registered) {
+		device_for_each_child(vm_cmdline_parent, buffer,
+				vm_cmdline_get_device);
+	}
+
 	return strlen(buffer) + 1;
 }
 

@@ -766,9 +766,9 @@ static int vm_unregister_cmdline_device(
 static void vm_unregister_cmdline_devices(void)
 {
 	if (vm_cmdline_parent_registered) {
-		device_for_each_child(&vm_cmdline_parent, NULL,
+		device_for_each_child(vm_cmdline_parent, NULL,
 				vm_unregister_cmdline_device);
-		device_unregister(&vm_cmdline_parent);
+		root_device_unregister(vm_cmdline_parent);
 		vm_cmdline_parent_registered = 0;
 	}
 }

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Bommarito <[email protected]>

commit e3046eeada299f917a8ad883af4434bfb86556b1 upstream.

random_recv_done() stores the device-reported used.len directly into vi->data_avail. copy_data() then indexes vi->data[] using vi->data_idx (advanced by previous copy_data() calls) and issues a memcpy() without re-validating either value against the posted buffer size sizeof(vi->data) (SMP_CACHE_BYTES bytes, typically 32 or 64).

A malicious or buggy virtio-rng backend can set used.len beyond sizeof(vi->data), steering the memcpy() past the end of the inline array into adjacent kmalloc-1k slab bytes. hwrng_fillfn() mixes those bytes into the guest RNG, and guest root can also observe them directly via /dev/hwrng.

Concrete impact is inside the guest:

- Memory-safety / hardening: any virtio-rng backend that over-reports used.len causes the driver to read past vi->data into unrelated slab contents. hwrng_fillfn() is a kernel thread that runs as soon as the device is probed; no guest userspace interaction is required to first-trigger the OOB.

- Cross-boundary leak (confidential-compute threat model): a malicious hypervisor cooperating with a malicious or compromised guest root userspace can use /dev/hwrng as a leak channel for guest-kernel heap data. The host sets a large used.len, guest root reads /dev/hwrng, and the returned bytes contain guest kernel slab contents that were adjacent to vi->data. In practice, confidential-compute guests (SEV-SNP, TDX) usually disable virtio-rng entirely, so this path is narrow, but the fix is still worth carrying because the underlying memory-safety bug contaminates the guest RNG on any host.

KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend has been patched to report used.len = 0x10000:

  BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0
  Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52
  Call Trace:
   __asan_memcpy+0x23/0x60
   virtio_read+0x394/0x5d0
   hwrng_fillfn+0xb2/0x470
   kthread+0x2cc/0x3a0
  Allocated by task 1:
   probe_common+0xa5/0x660
   virtio_dev_probe+0x549/0xbc0
  The buggy address belongs to the object at ffff88800ae0b800
   which belongs to the cache kmalloc-1k of size 1024
  The buggy address is located 0 bytes to the right of
   allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)

Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened usb9pfs_rx_complete() against unchecked device-reported length in the USB 9p transport.

With the clamp at point of use and array_index_nospec() in place, the same harness boots cleanly: copy_data() returns zero for the bogus report, the device-supplied bytes after data_idx are discarded, and the driver issues a fresh request.

Message-ID: <[email protected]>

---
 drivers/char/hw_random/virtio-rng.c |   23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

@@ -7,6 +7,7 @@
 #include <asm/barrier.h>
 #include <linux/err.h>
 #include <linux/hw_random.h>
+#include <linux/nospec.h>
 #include <linux/scatterlist.h>
 #include <linux/spinlock.h>
 #include <linux/virtio.h>

@@ -66,8 +67,26 @@ static void request_entropy(struct virtr
 static unsigned int copy_data(struct virtrng_info *vi, void *buf,
 			      unsigned int size)
 {
-	size = min_t(unsigned int, size, vi->data_avail);
-	memcpy(buf, vi->data + vi->data_idx, size);
+	unsigned int idx, avail;
+
+	/*
+	 * vi->data_avail was set from the device-reported used.len and
+	 * vi->data_idx was advanced by previous copy_data() calls.  A
+	 * malicious or buggy virtio-rng backend can drive either past
+	 * sizeof(vi->data).  Clamp at point of use and harden the index
+	 * with array_index_nospec() so the memcpy() below cannot be
+	 * steered into adjacent slab memory, including under
+	 * speculation.
+	 */
+	avail = min_t(unsigned int, vi->data_avail, sizeof(vi->data));
+	if (vi->data_idx >= avail) {
+		vi->data_avail = 0;
+		request_entropy(vi);
+		return 0;
+	}
+	size = min_t(unsigned int, size, avail - vi->data_idx);
+	idx = array_index_nospec(vi->data_idx, sizeof(vi->data));
+	memcpy(buf, vi->data + idx, size);
 	vi->data_idx += size;
 	vi->data_avail -= size;
 	if (vi->data_avail == 0)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alan Stern <[email protected]>

commit abf76d3239dee97b66e7241ad04811f1ce562e28 upstream.

The chaoskey driver has a use-after-free bug in its release routine. If the user closes the device file after the USB device has been unplugged, a debugging log statement will try to access the usb_interface structure after it has been deallocated:

	BUG: KASAN: slab-use-after-free in dev_driver_string (drivers/base/core.c:2406)
	Read of size 8 at addr ffff888168e8a0b8 by task chaoskey_raw_re/10106

	Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
	Call Trace:
	 <TASK>
	 dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
	 print_report (mm/kasan/report.c:378 mm/kasan/report.c:482)
	 kasan_report (mm/kasan/report.c:595)
	 dev_driver_string (drivers/base/core.c:2406)
	 __dynamic_dev_dbg (lib/dynamic_debug.c:906)
	 chaoskey_release (drivers/usb/misc/chaoskey.c:323)
	 __fput (fs/file_table.c:510)
	 fput_close_sync (fs/file_table.c:615)
	 __x64_sys_close (fs/open.c:1507 fs/open.c:1492 fs/open.c:1492)
	 do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
	 entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)

The driver's last reference to the interface structure is dropped in the chaoskey_free() routine, so the code must not use the interface -- even in a debugging statement -- after that routine returns. (Exception: If we know that another reference is held by someone else, such as the device core while the disconnect routine runs, there's no problem. Thanks to Johan Hovold for pointing this out.)

Since the bad access is part of an unimportant debugging statement, we can fix the problem simply by removing the whole statement.

---
 drivers/usb/misc/chaoskey.c |    1 -
 1 file changed, 1 deletion(-)

@@ -320,7 +320,6 @@ bail:
 	mutex_unlock(&dev->lock);
 destruction:
 	mutex_unlock(&chaoskey_list_lock);
-	usb_dbg(interface, "release success");
 	return rv;
 }
 

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Runyu Xiao <[email protected]>

commit 010382937fb69892b3469ac4d30af072262f59e8 upstream.

dwc3_gadget_suspend() takes dwc->lock with IRQs disabled and then calls dwc3_disconnect_gadget(). For async callbacks that helper only uses plain spin_unlock()/spin_lock(), so the gadget ->disconnect() callback still runs with IRQs disabled and any sleepable callback trips Lockdep.

This issue was found by our static analysis tool and then manually reviewed against the current tree.

The grounded PoC kept the dwc3_gadget_suspend() -> dwc3_disconnect_gadget() -> gadget_driver->disconnect() chain, and Lockdep reported:

  BUG: sleeping function called from invalid context
  gadget_disconnect+0x21/0x39 [vuln_msv]
  dwc3_gadget_suspend.constprop.0+0x2b/0x42 [vuln_msv]

Keep the disconnect callback selection in one common helper, but add a sleepable suspend-side wrapper which snapshots the callback under dwc->lock and then runs it after spin_unlock_irqrestore(). The regular event path still uses the existing spin_unlock()/spin_lock() window.

---
 drivers/usb/dwc3/gadget.c |   43 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 7 deletions(-)

@@ -3934,15 +3934,48 @@ static void dwc3_endpoint_interrupt(stru
 	}
 }
 
+static bool dwc3_prepare_disconnect_gadget(struct dwc3 *dwc,
+					   struct usb_gadget_driver **driver,
+					   struct usb_gadget **gadget)
+{
+	if (!dwc->async_callbacks || !dwc->gadget_driver ||
+	    !dwc->gadget_driver->disconnect)
+		return false;
+
+	*driver = dwc->gadget_driver;
+	*gadget = dwc->gadget;
+
+	return true;
+}
+
 static void dwc3_disconnect_gadget(struct dwc3 *dwc)
 {
-	if (dwc->async_callbacks && dwc->gadget_driver->disconnect) {
+	struct usb_gadget_driver *driver;
+	struct usb_gadget *gadget;
+
+	if (dwc3_prepare_disconnect_gadget(dwc, &driver, &gadget)) {
 		spin_unlock(&dwc->lock);
-		dwc->gadget_driver->disconnect(dwc->gadget);
+		driver->disconnect(gadget);
 		spin_lock(&dwc->lock);
 	}
 }
 
+static void dwc3_disconnect_gadget_sleepable(struct dwc3 *dwc)
+{
+	struct usb_gadget_driver *driver;
+	struct usb_gadget *gadget;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	if (!dwc3_prepare_disconnect_gadget(dwc, &driver, &gadget)) {
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		return;
+	}
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+	driver->disconnect(gadget);
+}
+
 static void dwc3_suspend_gadget(struct dwc3 *dwc)
 {
 	if (dwc->async_callbacks && dwc->gadget_driver->suspend) {

@@ -4836,7 +4869,6 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 
 int dwc3_gadget_suspend(struct dwc3 *dwc)
 {
-	unsigned long flags;
 	int ret;
 
 	ret = dwc3_gadget_soft_disconnect(dwc);

@@ -4850,10 +4882,7 @@ int dwc3_gadget_suspend(struct dwc3 *dwc
 		return -EAGAIN;
 	}
 
-	spin_lock_irqsave(&dwc->lock, flags);
-	if (dwc->gadget_driver)
-		dwc3_disconnect_gadget(dwc);
-	spin_unlock_irqrestore(&dwc->lock, flags);
+	dwc3_disconnect_gadget_sleepable(dwc);
 
 	return 0;
 }

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Cen Zhang <[email protected]>

commit 0bfeec21984fedd32987f4e4c0cde34b445af404 upstream.

usbio_disconnect() walks usbio->cli_list in reverse and uninitializes each auxiliary device. auxiliary_device_uninit() drops the device reference, and for an unbound child that can run usbio_auxdev_release() and free the containing struct usbio_client.

list_for_each_entry_reverse() advances after the loop body by reading client->link.prev. If the current client is freed by auxiliary_device_uninit(), the iterator dereferences freed memory.

Use list_for_each_entry_safe_reverse() so the previous client is cached before the body can drop the final reference. This preserves reverse teardown order while keeping the next iterator cursor independent of the current client's lifetime.

Validation reproduced this kernel report:

BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150

Call Trace:
 <TASK>
 dump_stack_lvl+0x66/0xa0
 print_report+0xce/0x630
 ? usbio_disconnect+0x12e/0x150
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? __virt_addr_valid+0x188/0x320
 ? usbio_disconnect+0x12e/0x150
 kasan_report+0xe0/0x110
 ? usbio_disconnect+0x12e/0x150
 usbio_disconnect+0x12e/0x150
 usb_unbind_interface+0xf3/0x400
 really_probe+0x316/0x660
 __driver_probe_device+0x106/0x240
 driver_probe_device+0x4a/0x110
 __device_attach_driver+0xf1/0x1a0
 ? __pfx___device_attach_driver+0x10/0x10
 bus_for_each_drv+0xf9/0x160
 ? __pfx_bus_for_each_drv+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? trace_hardirqs_on+0x18/0x130
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? _raw_spin_unlock_irqrestore+0x44/0x60
 __device_attach+0x133/0x2a0
 ? __pfx___device_attach+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? do_raw_spin_unlock+0x9a/0x100
 ? srso_alias_return_thunk+0x5/0xfbef5
 device_initial_probe+0x55/0x70
 bus_probe_device+0x4a/0xd0
 device_add+0x9b9/0xc10
 ? __pfx_device_add+0x10/0x10
 ? _raw_spin_unlock_irqrestore+0x44/0x60
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? lockdep_hardirqs_on_prepare+0xea/0x1a0
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? usb_enable_lpm+0x3c/0x260
 usb_set_configuration+0xb64/0xf20
 usb_generic_driver_probe+0x5f/0x90
 usb_probe_device+0x71/0x1b0
 really_probe+0x46b/0x660
 __driver_probe_device+0x106/0x240
 driver_probe_device+0x4a/0x110
 __device_attach_driver+0xf1/0x1a0
 ? __pfx___device_attach_driver+0x10/0x10
 bus_for_each_drv+0xf9/0x160
 ? __pfx_bus_for_each_drv+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? trace_hardirqs_on+0x18/0x130
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? _raw_spin_unlock_irqrestore+0x44/0x60
 __device_attach+0x133/0x2a0
 ? __pfx___device_attach+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? do_raw_spin_unlock+0x9a/0x100
 ? srso_alias_return_thunk+0x5/0xfbef5
 device_initial_probe+0x55/0x70
 bus_probe_device+0x4a/0xd0
 device_add+0x9b9/0xc10
 ? __pfx_device_add+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? add_device_randomness+0xb7/0xf0
 usb_new_device+0x492/0x870
 hub_event+0x1b10/0x29c0
 ? __pfx_hub_event+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? lock_acquire+0x187/0x300
 ? process_one_work+0x475/0xb90
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? lock_release+0xc8/0x290
 ? srso_alias_return_thunk+0x5/0xfbef5
 process_one_work+0x4d7/0xb90
 ? __pfx_process_one_work+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? __list_add_valid_or_report+0x37/0xf0
 ? __pfx_hub_event+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 worker_thread+0x2d8/0x570
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x1ad/0x1f0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x3c9/0x540
 ? __pfx_ret_from_fork+0x10/0x10
 ? srso_alias_return_thunk+0x5/0xfbef5
 ? __switch_to+0x2e9/0x730
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

---
 drivers/usb/misc/usbio.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -518,7 +518,7 @@ static int usbio_resume(struct usb_inter
 static void usbio_disconnect(struct usb_interface *intf)
 {
 	struct usbio_device *usbio = usb_get_intfdata(intf);
-	struct usbio_client *client;
+	struct usbio_client *client, *next;
 
 	/* Wakeup any clients waiting for a reply */
 	usbio->rxdat_len = 0;

@@ -535,7 +535,7 @@ static void usbio_disconnect(struct usb_
 	usb_kill_urb(usbio->urb);
 	usb_free_urb(usbio->urb);
 
-	list_for_each_entry_reverse(client, &usbio->cli_list, link) {
+	list_for_each_entry_safe_reverse(client, next, &usbio->cli_list, link) {
 		auxiliary_device_delete(&client->auxdev);
 		auxiliary_device_uninit(&client->auxdev);
 	}

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Yizhou Zhao <[email protected]>

commit 1720db928e5a58ca7d75ac1d514c3b73fd7061a7 upstream.

lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding lowpan_nhc_lock. If the descriptor has no uncompress callback, the error path drops the lock before printing nhc->name.

lowpan_nhc_del() removes descriptors under the same lock and then relies on synchronize_net() before the owning module can be unloaded. That only waits for net RX RCU readers. lowpan_header_decompress() is also exported and can be reached from callers that are not necessarily covered by the net core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive path.

This leaves a race where one task drops lowpan_nhc_lock in the error path, another task unregisters and frees the matching descriptor after synchronize_net() returns, and the first task then dereferences nhc->name for the warning.

With the post-unlock window widened, KASAN reports:

  BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220
  Read of size 8
  lowpan_nhc_do_uncompression
  lowpan_header_decompress

Fix this by printing the warning before dropping lowpan_nhc_lock, so the descriptor name is read while unregister is still excluded. The malformed packet is still rejected with -ENOTSUPP.

---
 net/6lowpan/nhc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -117,9 +117,9 @@ int lowpan_nhc_do_uncompression(struct s
 				return ret;
 			}
 		} else {
-			spin_unlock_bh(&lowpan_nhc_lock);
 			netdev_warn(dev, "received nhc id for %s which is not implemented.\n",
 				    nhc->name);
+			spin_unlock_bh(&lowpan_nhc_lock);
 			return -ENOTSUPP;
 		}
 	} else {

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Samuel Page <[email protected]>

commit 2b66974a1b6134a4bbc3bfed181f7418f688eb54 upstream.

A broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its data area. tipc_get_gap_ack_blks() only verifies that the record's len field is self-consistent with its ugack_cnt/bgack_cnt counts (sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check that the record actually fits in the message data area, msg_data_sz().

The unicast caller tipc_link_proto_rcv() bounds it ("if (glen > dlen) break;"), but the broadcast caller tipc_bcast_sync_rcv() discards the returned size, so tipc_link_advance_transmq() copies the record off the receive skb with an attacker-controlled count:

	this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
			  GFP_ATOMIC);

A TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one ordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its data area is short, carrying a Gap ACK record with len = 0x400, bgack_cnt = 0xff and ugack_cnt = 0. len then equals struct_size(p, gacks, 255), so the consistency check passes and ga is non-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out of the much smaller skb:

  BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60
  Read of size 1024 at addr ffff0000c7030d38 by task poc864/69
  Call trace:
   kmemdup_noprof+0x48/0x60
   tipc_link_advance_transmq+0x86c/0xb80
   tipc_link_bc_ack_rcv+0x19c/0x1e0
   tipc_bcast_sync_rcv+0x1c4/0x2c4
   tipc_rcv+0x85c/0x1340
   tipc_l2_rcv_msg+0xac/0x104
  The buggy address belongs to the object at ffff0000c7030d00
   which belongs to the cache skbuff_small_head of size 704
  The buggy address is located 56 bytes inside of
   allocated 704-byte region [ffff0000c7030d00, ffff0000c7030fc0)

The copied-out bytes are subsequently consumed as gap/ack values, but the read is already out of bounds at the kmemdup() regardless of how they are used.

The unicast STATE path drops such a message: "if (glen > dlen) break;" skips the rest of STATE_MSG handling and the skb is freed. Make the broadcast path drop it too. tipc_bcast_sync_rcv() now bounds the record against msg_data_sz() and, when it does not fit, reports it back through tipc_node_bc_sync_rcv() to tipc_rcv() so the skb is discarded rather than processed. ga is not cleared on this path: ga == NULL already means "legacy peer without Selective ACK", a distinct legitimate state.

---
 net/tipc/bcast.c |   22 ++++++++++++++--------
 net/tipc/bcast.h |    2 +-
 net/tipc/node.c  |   15 ++++++++++++---
 3 files changed, 27 insertions(+), 12 deletions(-)

@@ -497,12 +497,13 @@ void tipc_bcast_ack_rcv(struct net *net,
  */
 int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
 			struct tipc_msg *hdr,
-			struct sk_buff_head *retrq)
+			struct sk_buff_head *retrq, bool *valid)
 {
 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 	struct tipc_gap_ack_blks *ga;
 	struct sk_buff_head xmitq;
 	int rc = 0;
+	u16 glen;
 
 	__skb_queue_head_init(&xmitq);
 

@@ -510,13 +511,18 @@ int tipc_bcast_sync_rcv(struct net *net,
 	if (msg_type(hdr) != STATE_MSG) {
 		tipc_link_bc_init_rcv(l, hdr);
 	} else if (!msg_bc_ack_invalid(hdr)) {
-		tipc_get_gap_ack_blks(&ga, l, hdr, false);
-		if (!sysctl_tipc_bc_retruni)
-			retrq = &xmitq;
-		rc = tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr),
-					  msg_bc_gap(hdr), ga, &xmitq,
-					  retrq);
-		rc |= tipc_link_bc_sync_rcv(l, hdr, &xmitq);
+		glen = tipc_get_gap_ack_blks(&ga, l, hdr, false);
+		if (glen > msg_data_sz(hdr)) {
+			/* Malformed Gap ACK blocks; caller drops the msg */
+			*valid = false;
+		} else {
+			if (!sysctl_tipc_bc_retruni)
+				retrq = &xmitq;
+			rc = tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr),
+						  msg_bc_gap(hdr), ga, &xmitq,
+						  retrq);
+			rc |= tipc_link_bc_sync_rcv(l, hdr, &xmitq);
+		}
 	}
 	tipc_bcast_unlock(net);
 

@@ -97,7 +97,7 @@ void tipc_bcast_ack_rcv(struct net *net,
 			struct tipc_msg *hdr);
 int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
 			struct tipc_msg *hdr,
-			struct sk_buff_head *retrq);
+			struct sk_buff_head *retrq, bool *valid);
 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg,
 			struct tipc_link *bcl);
 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[]);

@@ -1831,12 +1831,15 @@ static void tipc_node_mcast_rcv(struct t
 }
 
 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
-				  int bearer_id, struct sk_buff_head *xmitq)
+				  int bearer_id, struct sk_buff_head *xmitq,
+				  bool *valid)
 {
 	struct tipc_link *ucl;
 	int rc;
 
-	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr, xmitq);
+	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr, xmitq, valid);
+	if (!*valid)
+		return;
 
 	if (rc & TIPC_LINK_DOWN_EVT) {
 		tipc_node_reset_links(n);

@@ -2140,12 +2143,18 @@ rcv:
 
 	/* Ensure broadcast reception is in synch with peer's send state */
 	if (unlikely(usr == LINK_PROTOCOL)) {
+		bool valid = true;
+
 		if (unlikely(skb_linearize(skb))) {
 			tipc_node_put(n);
 			goto discard;
 		}
 		hdr = buf_msg(skb);
-		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
+		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq, &valid);
+		if (!valid) {
+			tipc_node_put(n);
+			goto discard;
+		}
 	} else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack)) {
 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
 	}

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Tautschnig <[email protected]>

commit 9f32f38265014fac7f5dc9490fb01a638ce6e121 upstream.

The SLAVE-path helpers buffer_to_user() and buffer_from_user() copy 'count' bytes into/out of the fixed-size kern_buf (size_buf == PCI_BUF_SIZE == 0x20000, 128 KiB) using *ppos as the offset, without bounding *ppos + count against size_buf.

vme_user_write()/vme_user_read() only clamp count to the VME window size (image_size = vme_get_size(resource)), which VME_SET_SLAVE sets from the user-supplied slave.size -- validated against the VME address space (up to VME_A32_MAX = 4 GiB), not against PCI_BUF_SIZE. When the window exceeds 128 KiB, a write()/read() copies past the kern_buf allocation.

Clamp count against size_buf in both helpers, with an early return when *ppos is already at/after the buffer end. *ppos is >= 0 here (the caller rejects negative offsets), so size_buf - *ppos cannot wrap. This mirrors the existing clamp in the MASTER-path helpers resource_to_user() / resource_from_user(), and matches the read()/write() convention of a short transfer at end-of-buffer.

Found by static analysis (CodeQL taint tracking + CBMC bounded model checking) and confirmed dynamically under KASAN with the vme_fake bridge:

  BUG: KASAN: slab-out-of-bounds in _copy_from_user+0x2d/0x80
  Write of size 262144 at addr ffff888004100000 by task trigger/68
    _copy_from_user+0x2d/0x80
    vme_user_write+0x13e/0x240 [vme_user]
    vfs_write+0x1b8/0x7a0
    ksys_write+0xb8/0x150

---
 drivers/staging/vme_user/vme_user.c |   22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

@@ -156,6 +156,17 @@ static ssize_t buffer_to_user(unsigned i
 {
 	void *image_ptr;
 
+	/*
+	 * The slave window (image_size) can exceed the fixed kern_buf
+	 * (size_buf == PCI_BUF_SIZE), so bound the copy to kern_buf.
+	 * *ppos is >= 0 here (checked by the caller), so the
+	 * subtraction below cannot wrap.
+	 */
+	if (*ppos >= image[minor].size_buf)
+		return 0;
+	if (count > image[minor].size_buf - *ppos)
+		count = image[minor].size_buf - *ppos;
+
 	image_ptr = image[minor].kern_buf + *ppos;
 	if (copy_to_user(buf, image_ptr, (unsigned long)count))
 		return -EFAULT;

@@ -168,6 +179,17 @@ static ssize_t buffer_from_user(unsigned
 {
 	void *image_ptr;
 
+	/*
+	 * The slave window (image_size) can exceed the fixed kern_buf
+	 * (size_buf == PCI_BUF_SIZE), so bound the copy to kern_buf.
+	 * *ppos is >= 0 here (checked by the caller), so the
+	 * subtraction below cannot wrap.
+	 */
+	if (*ppos >= image[minor].size_buf)
+		return 0;
+	if (count > image[minor].size_buf - *ppos)
+		count = image[minor].size_buf - *ppos;
+
 	image_ptr = image[minor].kern_buf + *ppos;
 	if (copy_from_user(image_ptr, buf, (unsigned long)count))
 		return -EFAULT;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Shoichiro Miyamoto <[email protected]>

commit 53b7c271f06be4dd5cfc8c6ef552a8355c891a7f upstream.

smb2_check_message() has a long-standing quirk that accepts a response whose calculated length is one byte larger than the bytes actually received ("server can return one byte more due to implied bcc[0]"). This was introduced to accommodate servers that omit the trailing bcc[0] overlap byte when no data area is present.

However, the exemption is applied unconditionally, regardless of whether the command actually carries a data area (has_smb2_data_area[]). When a response with a data area is subject to the +1 exemption, the reported data can extend one byte beyond the bytes actually received, yet smb2_check_message() still accepts it. The subsequent decoder then reads past the end of the receive buffer. This is reachable during NEGOTIATE and SESSION_SETUP, before the session is established.

The resulting out-of-bounds reads are visible under KASAN when mounting against a non-conforming server; both the SPNEGO/negTokenInit and the NTLMSSP challenge decoders are affected:

  BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x16a7/0x1b00
  Read of size 1 at addr ffff8880084d67c0 by task mount.cifs/81
  CPU: 1 UID: 0 PID: 81 Comm: mount.cifs Not tainted 7.1.0-rc6 #1
  Call Trace:
   <TASK>
   dump_stack_lvl+0x4e/0x70
   print_report+0x157/0x4c9
   kasan_report+0xce/0x100
   asn1_ber_decoder+0x16a7/0x1b00
   decode_negTokenInit+0x19/0x30
   SMB2_negotiate+0x31d9/0x4c90
   cifs_negotiate_protocol+0x1f2/0x3f0
   cifs_get_smb_ses+0x93f/0x17e0
   cifs_mount_get_session+0x7f/0x3a0
   cifs_mount+0xb4/0xcf0
   cifs_smb3_do_mount+0x23a/0x1500
   smb3_get_tree+0x3b0/0x630
   vfs_get_tree+0x82/0x2d0
   fc_mount+0x10/0x1b0
   path_mount+0x50d/0x1de0
   __x64_sys_mount+0x20b/0x270
   do_syscall_64+0xee/0x590
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  Allocated by task 85:
   kmem_cache_alloc_noprof+0x106/0x380
   mempool_alloc_noprof+0x116/0x1e0
   cifs_small_buf_get+0x31/0x80
   allocate_buffers+0x10d/0x2b0
   cifs_demultiplex_thread+0x1d5/0x1d50
   kthread+0x2c6/0x390
   ret_from_fork+0x36e/0x5a0
   ret_from_fork_asm+0x1a/0x30
  The buggy address is located 0 bytes to the right of
   allocated 448-byte region [ffff8880084d6600, ffff8880084d67c0)
   which belongs to the cache cifs_small_rq of size 448

  BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x36/0x50
  Read of size 329 at addr ffff88800726c678 by task mount.cifs/89
  CPU: 0 UID: 0 PID: 89 Comm: mount.cifs Tainted: G    B      7.1.0-rc6 #1
  Call Trace:
   <TASK>
   dump_stack_lvl+0x4e/0x70
   print_report+0x157/0x4c9
   kasan_report+0xce/0x100
   kasan_check_range+0x10f/0x1e0
   __asan_memcpy+0x23/0x60
   kmemdup_noprof+0x36/0x50
   decode_ntlmssp_challenge+0x457/0x680
   SMB2_sess_auth_rawntlmssp_negotiate+0x6f0/0xcb0
   SMB2_sess_setup+0x219/0x4f0
   cifs_setup_session+0x248/0xaf0
   cifs_get_smb_ses+0xf79/0x17e0
   cifs_mount_get_session+0x7f/0x3a0
   cifs_mount+0xb4/0xcf0
   cifs_smb3_do_mount+0x23a/0x1500
   smb3_get_tree+0x3b0/0x630
   vfs_get_tree+0x82/0x2d0
   fc_mount+0x10/0x1b0
   path_mount+0x50d/0x1de0
   __x64_sys_mount+0x20b/0x270
   do_syscall_64+0xee/0x590
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>
  Allocated by task 93:
   kmem_cache_alloc_noprof+0x106/0x380
   mempool_alloc_noprof+0x116/0x1e0
   cifs_small_buf_get+0x31/0x80
   allocate_buffers+0x10d/0x2b0
   cifs_demultiplex_thread+0x1d5/0x1d50
   kthread+0x2c6/0x390
   ret_from_fork+0x36e/0x5a0
   ret_from_fork_asm+0x1a/0x30
  The buggy address is located 120 bytes inside of
   allocated 448-byte region [ffff88800726c600, ffff88800726c7c0)
   which belongs to the cache cifs_small_rq of size 448

Restrict the +1 exemption to responses that have no data area, so that it still covers the bcc[0] omission it was meant for. When a data area is present, the +1 discrepancy instead means the reported data length overruns the received buffer, so the response must be rejected.

---
 fs/smb/client/smb2misc.c |   32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

@@ -19,6 +19,8 @@
 #include "nterr.h"
 #include "cached_dir.h"
 
+static unsigned int __smb2_calc_size(void *buf, bool *have_data);
+
 static int
 check_smb2_hdr(struct smb2_hdr *shdr, __u64 mid)
 {

@@ -144,6 +146,7 @@ smb2_check_message(char *buf, unsigned i
 	int command;
 	__u32 calc_len; /* calculated length */
 	__u64 mid;
+	bool have_data;
 
 	/* If server is a channel, select the primary channel */
 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;

@@ -227,7 +230,8 @@ smb2_check_message(char *buf, unsigned i
 		}
 	}
 
-	calc_len = smb2_calc_size(buf);
+	have_data = false;
+	calc_len = __smb2_calc_size(buf, &have_data);
 
 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
 	 * be 0, and not a real miscalculation */

@@ -246,8 +250,13 @@ smb2_check_message(char *buf, unsigned i
 		/* Windows 7 server returns 24 bytes more */
 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
 			return 0;
-		/* server can return one byte more due to implied bcc[0] */
-		if (calc_len == len + 1)
+		/*
+		 * Server can return one byte more due to implied bcc[0].
+		 * Allow it only when there is no data area; if data_length > 0
+		 * the +1 gap indicates an overreported data length rather than
+		 * the bcc[0] omission.
+		 */
+		if (calc_len == len + 1 && !have_data)
 			return 0;
 
 		/*

@@ -408,14 +417,17 @@ smb2_get_data_area_len(int *off, int *le
 /*
  * Calculate the size of the SMB message based on the fixed header
  * portion, the number of word parameters and the data portion of the message.
+ * If have_data is non-NULL, it is set to true when a non-empty data area was
+ * found (data_length > 0), allowing callers to distinguish the implied bcc[0]
+ * case (no data area) from an overreported data length.
  */
-unsigned int
-smb2_calc_size(void *buf)
+static unsigned int
+__smb2_calc_size(void *buf, bool *have_data)
 {
 	struct smb2_pdu *pdu = buf;
 	struct smb2_hdr *shdr = &pdu->hdr;
 	int offset; /* the offset from the beginning of SMB to data area */
-	int data_length; /* the length of the variable length data area */
+	int data_length = 0; /* the length of the variable length data area */
 	/* Structure Size has already been checked to make sure it is 64 */
 	int len = le16_to_cpu(shdr->StructureSize);
 

@@ -448,9 +460,17 @@ smb2_calc_size(void *buf)
 	}
 calc_size_exit:
 	cifs_dbg(FYI, "SMB2 len %d\n", len);
+	if (have_data)
+		*have_data = (data_length > 0);
 	return len;
 }
 
+unsigned int
+smb2_calc_size(void *buf)
+{
+	return __smb2_calc_size(buf, NULL);
+}
+
 /* Note: caller must free return buffer */
 __le16 *
 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hao-Qun Huang <[email protected]>

commit e8422d89e8af41d87f0e9db564be8e2634f4c602 upstream.

fake_init() allocates a location monitor resource and links it into fake_bridge->lm_resources. The init error path frees this list, but fake_exit() only frees the slave and master resource lists. Loading and unloading the module therefore triggers a kmemleak warning:

unreferenced object 0xffff8b8b82aebe40 (size 64):

    comm "init", pid 1, jiffies 4294894572
    backtrace (crc c1e013ef):
      kmemleak_alloc+0x4e/0x90
      __kmalloc_cache_noprof+0x338/0x430
      0xffffffffc0602246
      do_one_initcall+0x4f/0x320
      do_init_module+0x68/0x270
      load_module+0x2a3b/0x2d90

Free the lm_resources list in fake_exit() as well, before fake_bridge is freed.

---
 drivers/staging/vme_user/vme_fake.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -1239,6 +1239,7 @@ static void __exit fake_exit(void)
 {
 	struct list_head *pos = NULL;
 	struct list_head *tmplist;
+	struct vme_lm_resource *lm;
 	struct vme_master_resource *master_image;
 	struct vme_slave_resource *slave_image;
 	int i;

@@ -1269,6 +1270,13 @@ static void __exit fake_exit(void)
 
 	fake_crcsr_exit(fake_bridge);
 	/* resources are stored in link list */
+	list_for_each_safe(pos, tmplist, &fake_bridge->lm_resources) {
+		lm = list_entry(pos, struct vme_lm_resource, list);
+		list_del(pos);
+		kfree(lm);
+	}
+
+	/* resources are stored in link list */
 	list_for_each_safe(pos, tmplist, &fake_bridge->slave_resources) {
 		slave_image = list_entry(pos, struct vme_slave_resource, list);
 		list_del(pos);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hao-Qun Huang <[email protected]>

commit 151edde741f8bc7f2931c5f44ab376d32b0c8beb upstream.

tsi148_probe() allocates a location monitor resource and links it into tsi148_bridge->lm_resources. The probe error path frees this list, but tsi148_remove() only frees the dma, slave and master resource lists, so the location monitor resource is leaked on device unbind or module unload.

Free the lm_resources list in tsi148_remove() as well, before tsi148_bridge is freed.

---
 drivers/staging/vme_user/vme_tsi148.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -2536,6 +2536,7 @@ static void tsi148_remove(struct pci_dev
 {
 	struct list_head *pos = NULL;
 	struct list_head *tmplist;
+	struct vme_lm_resource *lm;
 	struct vme_master_resource *master_image;
 	struct vme_slave_resource *slave_image;
 	struct vme_dma_resource *dma_ctrlr;

@@ -2593,6 +2594,13 @@ static void tsi148_remove(struct pci_dev
 	tsi148_crcsr_exit(tsi148_bridge, pdev);
 
 	/* resources are stored in link list */
+	list_for_each_safe(pos, tmplist, &tsi148_bridge->lm_resources) {
+		lm = list_entry(pos, struct vme_lm_resource, list);
+		list_del(pos);
+		kfree(lm);
+	}
+
+	/* resources are stored in link list */
 	list_for_each_safe(pos, tmplist, &tsi148_bridge->dma_resources) {
 		dma_ctrlr = list_entry(pos, struct vme_dma_resource, list);
 		list_del(pos);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ricardo Ribalda <[email protected]>

commit c32fe4c4918c9aa49f61359e3b42619c4d8686de upstream.

If the driver's stripe information is invalid it can result in an integer underflow. Add a range check to avoid this kind of error.

This patch fixes the following smatch error:
drivers/staging/media/ipu3/ipu3-css-params.c:1792 imgu_css_cfg_acc_stripe() warn: 'acc->stripe.bds_out_stripes[0]->width - 2 * f' 4294967168 can't fit into 65535 'acc->stripe.bds_out_stripes[1]->offset'

---
 drivers/staging/media/ipu3/ipu3-css-params.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

@@ -1770,6 +1770,8 @@ static int imgu_css_cfg_acc_stripe(struc
 		acc->stripe.bds_out_stripes[0].width =
 			ALIGN(css_pipe->rect[IPU3_CSS_RECT_BDS].width, f);
 	} else {
+		u32 offset;
+
 		/* Image processing is divided into two stripes */
 		acc->stripe.bds_out_stripes[0].width =
 			acc->stripe.bds_out_stripes[1].width =

@@ -1788,8 +1790,10 @@ static int imgu_css_cfg_acc_stripe(struc
 			acc->stripe.bds_out_stripes[1].width += f;
 		}
 		/* Overlap between stripes is IPU3_UAPI_ISP_VEC_ELEMS * 4 */
-		acc->stripe.bds_out_stripes[1].offset =
-			acc->stripe.bds_out_stripes[0].width - 2 * f;
+		offset = acc->stripe.bds_out_stripes[0].width - 2 * f;
+		if (offset > 65535)
+			return -EINVAL;
+		acc->stripe.bds_out_stripes[1].offset = offset;
 	}
 
 	acc->stripe.effective_stripes[0].height =

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <[email protected]>

commit f4d51e55dd47ef467fbe37d8575e20eee41b092d upstream.

The load_primary_binaries() function is overly complex and has som large variables on the stack, which can cause warnings depending on CONFIG_FRAME_WARN setting:

drivers/staging/media/atomisp/pci/sh_css.c: In function 'load_primary_binaries':
drivers/staging/media/atomisp/pci/sh_css.c:5260:1: error: the frame size of 1560 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]

Half of the stack usage is for the prim_descr[] array, but only one member of the array is used at any given time.

Reduce the stack usage by turning the array into a single structure.

---
 drivers/staging/media/atomisp/pci/sh_css.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -5021,7 +5021,6 @@ static int load_primary_binaries(
 	struct ia_css_capture_settings *mycs;
 	unsigned int i;
 	bool need_extra_yuv_scaler = false;
-	struct ia_css_binary_descr prim_descr[MAX_NUM_PRIMARY_STAGES];
 
 	IA_CSS_ENTER_PRIVATE("");
 	assert(pipe);

@@ -5191,15 +5190,16 @@ static int load_primary_binaries(
 
 	/* Primary */
 	for (i = 0; i < mycs->num_primary_stage; i++) {
+		struct ia_css_binary_descr prim_descr;
 		struct ia_css_frame_info *local_vf_info = NULL;
 
 		if (pipe->enable_viewfinder[IA_CSS_PIPE_OUTPUT_STAGE_0] &&
 		    (i == mycs->num_primary_stage - 1))
 			local_vf_info = &vf_info;
-		ia_css_pipe_get_primary_binarydesc(pipe, &prim_descr[i],
+		ia_css_pipe_get_primary_binarydesc(pipe, &prim_descr,
 						   &prim_in_info, &prim_out_info,
 						   local_vf_info, i);
-		err = ia_css_binary_find(&prim_descr[i], &mycs->primary_binary[i]);
+		err = ia_css_binary_find(&prim_descr, &mycs->primary_binary[i]);
 		if (err) {
 			IA_CSS_LEAVE_ERR_PRIVATE(err);
 			return err;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit d3a9a8cf2d7fd61a2f63df61f6cbc0a9bb007cc0 upstream.

In both ipu7_isys_init() and ipu7_psys_init(), pdata is allocated and then passed to ipu7_bus_initialize_device(), which stores it in adev->pdata. The ipu7_bus_release() function frees adev->pdata when the device's reference count drops to zero.

Two error paths incorrectly call kfree(pdata) after the device teardown has already freed it:

1. When ipu7_mmu_init() fails: put_device() is called, which drops the reference count to zero and triggers ipu7_bus_release() -> kfree(pdata). The subsequent kfree(pdata) is a double-free.

2. When ipu7_bus_add_device() fails: it calls auxiliary_device_uninit() internally, which calls put_device() -> ipu7_bus_release() -> kfree(pdata). The subsequent kfree(pdata) is again a double-free.

Note that the kfree(pdata) when ipu7_bus_initialize_device() itself fails is correct, because in that case auxiliary_device_init() failed and the release function was never set up, so pdata must be freed manually.

Additionally, the error code was not saved before calling put_device(), causing ERR_CAST() to dereference the already-freed adev pointer when constructing the return value. Fix this by saving the error from dev_err_probe() before put_device() and returning ERR_PTR() instead.

Remove the redundant kfree(pdata) calls and fix the use-after-free in the return values of the two affected error paths.

---
 drivers/staging/media/ipu7/ipu7.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

index c771e763f8c5..310e3f24e571 100644
@@ -2169,21 +2169,18 @@ ipu7_isys_init(struct pci_dev *pdev, struct device *parent,
 	isys_adev->mmu = ipu7_mmu_init(dev, base, ISYS_MMID,
 				       &ipdata->hw_variant);
 	if (IS_ERR(isys_adev->mmu)) {
-		dev_err_probe(dev, PTR_ERR(isys_adev->mmu),
-			      "ipu7_mmu_init(isys_adev->mmu) failed\n");
+		ret = dev_err_probe(dev, PTR_ERR(isys_adev->mmu),
+				    "ipu7_mmu_init(isys_adev->mmu) failed\n");
 		put_device(&isys_adev->auxdev.dev);
-		kfree(pdata);
-		return ERR_CAST(isys_adev->mmu);
+		return ERR_PTR(ret);
 	}
 
 	isys_adev->mmu->dev = &isys_adev->auxdev.dev;
 	isys_adev->subsys = IPU_IS;
 
 	ret = ipu7_bus_add_device(isys_adev);
-	if (ret) {
-		kfree(pdata);
+	if (ret)
 		return ERR_PTR(ret);
-	}
 
 	return isys_adev;
 }

@@ -2216,21 +2213,18 @@ ipu7_psys_init(struct pci_dev *pdev, struct device *parent,
 	psys_adev->mmu = ipu7_mmu_init(&pdev->dev, base, PSYS_MMID,
 				       &ipdata->hw_variant);
 	if (IS_ERR(psys_adev->mmu)) {
-		dev_err_probe(&pdev->dev, PTR_ERR(psys_adev->mmu),
-			      "ipu7_mmu_init(psys_adev->mmu) failed\n");
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(psys_adev->mmu),
+				    "ipu7_mmu_init(psys_adev->mmu) failed\n");
 		put_device(&psys_adev->auxdev.dev);
-		kfree(pdata);
-		return ERR_CAST(psys_adev->mmu);
+		return ERR_PTR(ret);
 	}
 
 	psys_adev->mmu->dev = &psys_adev->auxdev.dev;
 	psys_adev->subsys = IPU_PS;
 
 	ret = ipu7_bus_add_device(psys_adev);
-	if (ret) {
-		kfree(pdata);
+	if (ret)
 		return ERR_PTR(ret);
-	}
 
 	return psys_adev;
 }

2.55.0

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit 5a752a616e756844388a1a45404db9fc29fec655 upstream.

supplicant_ie is a 256-byte array in struct security_priv. The WPA and WPA2 IE copy paths use:

    memcpy(padapter->securitypriv.supplicant_ie, &pwpa[0], wpa_ielen + 2);

where wpa_ielen is the raw IE length field (u8, 0-255). When a local user supplies a connect request via nl80211 with a crafted WPA IE of length 255, wpa_ielen + 2 equals 257, overflowing the 256-byte buffer by one byte into the adjacent last_mic_err_time field.

rtw_parse_wpa_ie() does not prevent this: its length consistency check compares *(wpa_ie+1) against (u8)(wpa_ie_len-2), which is (u8)(255) == 255 when wpa_ie_len = 257, so the check passes silently.

Add explicit bounds checks for both the WPA and WPA2 paths before the memcpy, rejecting any IE whose total size (wpa_ielen + 2) exceeds the supplicant_ie buffer.

---
 drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -1446,6 +1446,10 @@ static int rtw_cfg80211_set_wpa_ie(struc
 
 	pwpa = rtw_get_wpa_ie(buf, &wpa_ielen, ielen);
 	if (pwpa && wpa_ielen > 0) {
+		if (wpa_ielen + 2 > sizeof(padapter->securitypriv.supplicant_ie)) {
+			ret = -EINVAL;
+			goto exit;
+		}
 		if (rtw_parse_wpa_ie(pwpa, wpa_ielen + 2, &group_cipher, &pairwise_cipher, NULL) == _SUCCESS) {
 			padapter->securitypriv.dot11AuthAlgrthm = dot11AuthAlgrthm_8021X;
 			padapter->securitypriv.ndisauthtype = Ndis802_11AuthModeWPAPSK;

@@ -1455,6 +1459,10 @@ static int rtw_cfg80211_set_wpa_ie(struc
 
 	pwpa2 = rtw_get_wpa2_ie(buf, &wpa2_ielen, ielen);
 	if (pwpa2 && wpa2_ielen > 0) {
+		if (wpa2_ielen + 2 > sizeof(padapter->securitypriv.supplicant_ie)) {
+			ret = -EINVAL;
+			goto exit;
+		}
 		if (rtw_parse_wpa2_ie(pwpa2, wpa2_ielen + 2, &group_cipher, &pairwise_cipher, NULL) == _SUCCESS) {
 			padapter->securitypriv.dot11AuthAlgrthm = dot11AuthAlgrthm_8021X;
 			padapter->securitypriv.ndisauthtype = Ndis802_11AuthModeWPA2PSK;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit a1fc19d61f661d47204f095b593de507884849f7 upstream.

OnAuth() has two bugs in the shared-key authentication path.

When the Privacy bit is set, rtw_wep_decrypt() is called without verifying that the frame is long enough to contain a valid WEP IV and ICV. Inside rtw_wep_decrypt(), length is computed as:

length = len - WLAN_HDR_A3_LEN - iv_len

and then passed as (length - 4) to crc32_le(). If len is less than WLAN_HDR_A3_LEN + iv_len + icv_len (32 bytes), length - 4 is negative and, after the implicit cast to size_t, causes crc32_le() to read far beyond the frame buffer. Add a minimum length check before accessing the IV field and calling the decryption path.

When processing a seq=3 response, rtw_get_ie() stores the Challenge Text IE length in ie_len, but the subsequent memcmp() always reads 128 bytes regardless of ie_len. IEEE 802.11 mandates a challenge text of exactly 128 bytes; reject any IE whose length field differs, matching the check already applied to OnAuthClient().

---
 drivers/staging/rtl8723bs/core/rtw_mlme_ext.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

@@ -703,6 +703,9 @@ unsigned int OnAuth(struct adapter *pada
 	if ((pmlmeinfo->state&0x03) != WIFI_FW_AP_STATE)
 		return _FAIL;
 
+	if (len < WLAN_HDR_A3_LEN)
+		return _FAIL;
+
 	sa = GetAddr2Ptr(pframe);
 
 	auth_mode = psecuritypriv->dot11AuthAlgrthm;

@@ -714,6 +717,9 @@ unsigned int OnAuth(struct adapter *pada
 		prxattrib->hdrlen = WLAN_HDR_A3_LEN;
 		prxattrib->encrypt = _WEP40_;
 
+		if (len < WLAN_HDR_A3_LEN + 8)
+			return _FAIL;
+
 		iv = pframe+prxattrib->hdrlen;
 		prxattrib->key_index = ((iv[3]>>6)&0x3);
 

@@ -818,7 +824,7 @@ unsigned int OnAuth(struct adapter *pada
 			p = rtw_get_ie(pframe + WLAN_HDR_A3_LEN + 4 + _AUTH_IE_OFFSET_, WLAN_EID_CHALLENGE, (int *)&ie_len,
 					len - WLAN_HDR_A3_LEN - _AUTH_IE_OFFSET_ - 4);
 
-			if (!p || ie_len <= 0) {
+			if (!p || ie_len != 128) {
 				status = WLAN_STATUS_CHALLENGE_FAIL;
 				goto auth_fail;
 			}

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit f9654207e92283e0acac5d64fe5f8835383b5a23 upstream.

The IE parsing loop in OnAssocRsp() advances by (pIE->length + 2) each iteration but only guards on i < pkt_len. When a malicious AP sends an AssocResponse whose last IE has only one byte remaining in the frame (the element_id byte lands at pkt_len-1), the loop reads pIE->length from pframe[pkt_len], which is one byte past the allocated receive buffer.

Additionally, even when the header bytes are in bounds, pIE->length itself can extend the data window beyond pkt_len, silently passing a truncated IE to the handler functions.

Add two guards at the top of the loop body:
1. Break if fewer than sizeof(*pIE) bytes remain (can't read header).
2. Break if the IE's declared data extends past pkt_len.

---
 drivers/staging/rtl8723bs/core/rtw_mlme_ext.c |    4 ++++
 1 file changed, 4 insertions(+)

@@ -1430,7 +1430,11 @@ unsigned int OnAssocRsp(struct adapter *
 	/* to handle HT, WMM, rate adaptive, update MAC reg */
 	/* for not to handle the synchronous IO in the tasklet */
 	for (i = (6 + WLAN_HDR_A3_LEN); i < pkt_len;) {
+		if (i + sizeof(*pIE) > pkt_len)
+			break;
 		pIE = (struct ndis_80211_var_ie *)(pframe + i);
+		if (i + sizeof(*pIE) + pIE->length > pkt_len)
+			break;
 
 		switch (pIE->element_id) {
 		case WLAN_EID_VENDOR_SPECIFIC:

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit ed51de4a86e173c3b0ef78e039c2e49e08b11f16 upstream.

The IE parsing loop in update_beacon_info() advances by (pIE->length + 2) each iteration but only guards on i < len. When a malicious AP sends a Beacon whose last IE has only one byte remaining in the frame (the element_id byte lands at len-1), the loop reads pIE->length from one byte past the allocated receive buffer.

Additionally, even when the header bytes are in bounds, pIE->length itself can extend the data window beyond len, passing a truncated IE to the handler functions.

Add two guards at the top of the loop body:
1. Break if fewer than sizeof(*pIE) bytes remain (can't read header).
2. Break if the IE's declared data extends past len.

Also replace i += (pIE->length + 2) with i += sizeof(*pIE) + pIE->length for consistency with the sizeof(*pIE) guards added above.

---
 drivers/staging/rtl8723bs/core/rtw_wlan_util.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

@@ -1288,7 +1288,11 @@ void update_beacon_info(struct adapter *
 	len = pkt_len - (_BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN);
 
 	for (i = 0; i < len;) {
+		if (i + sizeof(*pIE) > len)
+			break;
 		pIE = (struct ndis_80211_var_ie *)(pframe + (_BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN) + i);
+		if (i + sizeof(*pIE) + pIE->length > len)
+			break;
 
 		switch (pIE->element_id) {
 		case WLAN_EID_VENDOR_SPECIFIC:

@@ -1313,7 +1317,7 @@ void update_beacon_info(struct adapter *
 			break;
 		}
 
-		i += (pIE->length + 2);
+		i += sizeof(*pIE) + pIE->length;
 	}
 }
 

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit ef61d628dfad38fead1fd2e08979ae9126d011d5 upstream.

Two IE parsing loops are missing the header bounds checks before they dereference pIE->length:

- issue_assocreq() walks pmlmeinfo->network.ies to build the association request. If the stored IE data ends with only an element_id byte and no length byte, pIE->length is read one byte past the end of the buffer.

- join_cmd_hdl() walks pnetwork->ies during station join and has the same problem under the same conditions.

Both buffers are filled from AP beacon and probe-response frames, so a malicious AP that sends a truncated final IE can trigger the issue.

Apply the two-guard pattern established in update_beacon_info():
1. Break if fewer than sizeof(*pIE) bytes remain.
2. Break if the IE's declared data extends past the buffer end.

---
 drivers/staging/rtl8723bs/core/rtw_mlme_ext.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -2972,7 +2972,11 @@ void issue_assocreq(struct adapter *pada
 
 	/* vendor specific IE, such as WPA, WMM, WPS */
 	for (i = sizeof(struct ndis_802_11_fix_ie); i < pmlmeinfo->network.ie_length;) {
+		if (i + sizeof(*pIE) > pmlmeinfo->network.ie_length)
+			break;
 		pIE = (struct ndis_80211_var_ie *)(pmlmeinfo->network.ies + i);
+		if (i + sizeof(*pIE) + pIE->length > pmlmeinfo->network.ie_length)
+			break;
 
 		switch (pIE->element_id) {
 		case WLAN_EID_VENDOR_SPECIFIC:

@@ -5370,7 +5374,11 @@ u8 join_cmd_hdl(struct adapter *padapter
 
 	/* sizeof(struct ndis_802_11_fix_ie) */
 	for (i = _FIXED_IE_LENGTH_; i < pnetwork->ie_length;) {
+		if (i + sizeof(*pIE) > pnetwork->ie_length)
+			break;
 		pIE = (struct ndis_80211_var_ie *)(pnetwork->ies + i);
+		if (i + sizeof(*pIE) + pIE->length > pnetwork->ie_length)
+			break;
 
 		switch (pIE->element_id) {
 		case WLAN_EID_VENDOR_SPECIFIC:/* Get WMM IE. */

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit 3bf39f711ff27c64be8680a8938bcc5001982e81 upstream.

The loop in is_ap_in_tkip() iterates over IEs without verifying that enough bytes remain before dereferencing the IE header or its payload:

- pIE->element_id and pIE->length are read without checking that i + sizeof(*pIE) <= ie_length, so a truncated IE at the end of the buffer causes an OOB read.

- For WLAN_EID_VENDOR_SPECIFIC the code compares pIE->data + 12, which requires pIE->length >= 16. For WLAN_EID_RSN it compares pIE->data + 8, requiring pIE->length >= 12. Neither requirement is checked.

Add the missing IE header and payload bounds checks and guard each data access with an explicit pIE->length minimum, matching the pattern established in update_beacon_info().

---
 drivers/staging/rtl8723bs/core/rtw_wlan_util.c |   14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

@@ -1333,15 +1333,23 @@ unsigned int is_ap_in_tkip(struct adapte
 		for (i = sizeof(struct ndis_802_11_fix_ie); i < pmlmeinfo->network.ie_length;) {
 			pIE = (struct ndis_80211_var_ie *)(pmlmeinfo->network.ies + i);
 
+			if (i + sizeof(*pIE) > pmlmeinfo->network.ie_length)
+				break;
+			if (i + sizeof(*pIE) + pIE->length > pmlmeinfo->network.ie_length)
+				break;
+
 			switch (pIE->element_id) {
 			case WLAN_EID_VENDOR_SPECIFIC:
-				if ((!memcmp(pIE->data, RTW_WPA_OUI, 4)) && (!memcmp((pIE->data + 12), WPA_TKIP_CIPHER, 4)))
+				if (pIE->length >= 16 &&
+				    !memcmp(pIE->data, RTW_WPA_OUI, 4) &&
+				    !memcmp((pIE->data + 12), WPA_TKIP_CIPHER, 4))
 					return true;
 
 				break;
 
 			case WLAN_EID_RSN:
-				if (!memcmp((pIE->data + 8), RSN_TKIP_CIPHER, 4))
+				if (pIE->length >= 12 &&
+				    !memcmp((pIE->data + 8), RSN_TKIP_CIPHER, 4))
 					return true;
 				break;
 

@@ -1349,7 +1357,7 @@ unsigned int is_ap_in_tkip(struct adapte
 				break;
 			}
 
-			i += (pIE->length + 2);
+			i += sizeof(*pIE) + pIE->length;
 		}
 
 		return false;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexandru Hossu <[email protected]>

commit f8001e1a516ba3b495728c65b61f799cbfad6bd0 upstream.

HT_caps_handler() iterates pIE->length bytes and writes into HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct HT_caps_element). Because pIE->length is a raw u8 from an over-the-air 802.11 AssocResponse frame and is never validated, a malicious AP can set it up to 255, causing up to 229 bytes of out-of-bounds writes into adjacent fields of struct mlme_ext_info.

Truncate the iteration count to the size of HT_caps.u.HT_cap using umin() so that data from a longer-than-expected IE is silently ignored rather than written out of bounds, preserving interoperability with APs that pad the element. An early return on oversized IEs was considered but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1 assignment that precedes the loop, silently disabling HT mode for APs that append extra bytes to the HT Capabilities IE.

---
 drivers/staging/rtl8723bs/core/rtw_wlan_util.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -935,7 +935,8 @@ void HT_caps_handler(struct adapter *pad
 
 	pmlmeinfo->HT_caps_enable = 1;
 
-	for (i = 0; i < (pIE->length); i++) {
+	for (i = 0; i < umin(pIE->length,
+			     sizeof(pmlmeinfo->HT_caps.u.HT_cap)); i++) {
 		if (i != 2) {
 			/* Commented by Albert 2010/07/12 */
 			/* Got the endian issue here. */

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dawei Feng <[email protected]>

commit 6d827ade51a24e18d81afb9f32756d339520a14c upstream.

When meson_allocate_chanlist() fails after a partial allocation, it already unwinds the allocated chanlist state through its local error path. meson_crypto_probe() then jump to error_flow and calls meson_free_chanlist() again, causing the same per-flow resources to be torn down twice. In the reproduced failure path, the second teardown re-entered crypto_engine_exit() on an already destroyed worker and KASAN reported a slab-use-after-free in kthread_destroy_worker().

Prevent double-free by handling partial allocation failures locally within meson_allocate_chanlist() and skipping the outer cleanup path.

The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available.

The bug was reproduced in a QEMU x86_64 guest booted with KASAN on v7.1, using the reproducer under tools/testing/meson_crypto_probe. The reproducer forces the second dma_alloc_attrs() call in the gxl-crypto probe path to return NULL, making meson_allocate_chanlist() fail after partial initialization. On the unpatched kernel this reliably triggered a slab-use-after-free. With this fix applied, the same reproducer no longer emits any KASAN report and the probe fails cleanly with -ENOMEM.

    ==================================================================
    BUG: KASAN: slab-use-after-free in kthread_destroy_worker+0xb2/0xd0
    Read of size 8 at addr ff1100010c057a68 by task insmod/265

    CPU: 1 UID: 0 PID: 265 Comm: insmod Tainted: G           O        7.1.0-rc2-00376-g810af9adc907-dirty #10 PREEMPT(lazy)
    Tainted: [O]=OOT_MODULE
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
    Call Trace:
     <TASK>
     dump_stack_lvl+0x68/0xa0
     print_report+0xcb/0x5e0
     ? __virt_addr_valid+0x21d/0x3f0
     ? kthread_destroy_worker+0xb2/0xd0
     ? kthread_destroy_worker+0xb2/0xd0
     kasan_report+0xca/0x100
     ? kthread_destroy_worker+0xb2/0xd0
     kthread_destroy_worker+0xb2/0xd0
     meson_crypto_probe+0x4d0/0xc10 [amlogic_gxl_crypto]
     platform_probe+0x99/0x140
     really_probe+0x1c6/0x6a0
     ? __pfx___device_attach_driver+0x10/0x10
     __driver_probe_device+0x248/0x310
     ? acpi_driver_match_device+0xb0/0x100
     driver_probe_device+0x48/0x210
     ? __pfx___device_attach_driver+0x10/0x10
     __device_attach_driver+0x160/0x320
     bus_for_each_drv+0x104/0x190
     ? __pfx_bus_for_each_drv+0x10/0x10
     ? _raw_spin_unlock_irqrestore+0x2c/0x50
     __device_attach+0x19d/0x3b0
     ? __pfx___device_attach+0x10/0x10
     ? do_raw_spin_unlock+0x53/0x220
     device_initial_probe+0x78/0xa0
     bus_probe_device+0x5b/0x130
     device_add+0xcfd/0x1430
     ? __pfx_device_add+0x10/0x10
     ? insert_resource+0x34/0x50
     ? lock_release+0xc9/0x290
     platform_device_add+0x24e/0x590
     ? __pfx_meson_crypto_probe_repro_init+0x10/0x10 [meson_crypto_probe_repro]
     meson_crypto_probe_repro_init+0x330/0xff0 [meson_crypto_probe_repro]
     do_one_initcall+0xc0/0x450
     ? __pfx_do_one_initcall+0x10/0x10
     ? _raw_spin_unlock_irqrestore+0x2c/0x50
     ? __create_object+0x59/0x80
     ? kasan_unpoison+0x27/0x60
     do_init_module+0x27b/0x7d0
     ? __pfx_do_init_module+0x10/0x10
     ? kasan_quarantine_put+0x84/0x1d0
     ? kfree+0x32c/0x510
     ? load_module+0x561e/0x5ff0
     load_module+0x54fe/0x5ff0
     ? __pfx_load_module+0x10/0x10
     ? security_file_permission+0x20/0x40
     ? kernel_read_file+0x23d/0x6e0
     ? mmap_region+0x235/0x4a0
     ? __pfx_kernel_read_file+0x10/0x10
     ? __file_has_perm+0x2c0/0x3e0
     init_module_from_file+0x158/0x180
     ? __pfx_init_module_from_file+0x10/0x10
     ? __lock_acquire+0x45a/0x1ba0
     ? idempotent_init_module+0x315/0x610
     ? lock_release+0xc9/0x290
     ? lockdep_init_map_type+0x4b/0x220
     ? do_raw_spin_unlock+0x53/0x220
     idempotent_init_module+0x330/0x610
     ? __pfx_idempotent_init_module+0x10/0x10
     ? __pfx_cred_has_capability.isra.0+0x10/0x10
     ? ksys_mmap_pgoff+0x385/0x520
     __x64_sys_finit_module+0xbe/0x120
     do_syscall_64+0x115/0x690
     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    RIP: 0033:0x7f7d6d31690d
    Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d f3 b4 0f 00 f7 d8 >
    RSP: 002b:00007fffc027ac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
    RAX: ffffffffffffffda RBX: 000055f7b81967c0 RCX: 00007f7d6d31690d
    RDX: 0000000000000000 RSI: 000055f79a0d6cd2 RDI: 0000000000000003
    RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
    R10: 0000000000000003 R11: 0000000000000246 R12: 000055f79a0d6cd2
    R13: 000055f7b8196790 R14: 000055f79a0d5888 R15: 000055f7b81968e0
     </TASK>

---
 drivers/crypto/amlogic/amlogic-gxl-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -291,8 +291,8 @@ static int meson_crypto_probe(struct pla
 	return 0;
 error_alg:
 	meson_unregister_algs(mc);
-error_flow:
 	meson_free_chanlist(mc, MAXFLOW - 1);
+error_flow:
 	clk_disable_unprepare(mc->busclk);
 	return err;
 }

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Bommarito <[email protected]>

commit 6c9dddeb582fde005360f4fe02c760d45ca05fb5 upstream.

krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL completion callback and treat any negative return from crypto_aead_{encrypt,decrypt}() as terminal, falling through to kfree_sensitive(buffer). When the encrypt_name resolves to an async AEAD instance the request returns -EINPROGRESS, the buffer is freed while the backend's worker still holds a pointer, and the worker dereferences the freed slab on completion.

KASAN report under UML+SLUB with a synthetic async aead backend bound to krb5->encrypt_name:

  BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7

The helpers were written synchronously, so filter the async instances out at allocation time instead of plumbing crypto_wait_req() through every call site.

Reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and net/ceph/crypto.c on systems with an async AEAD provider bound to the krb5 enctype name.

---
 crypto/krb5/krb5_api.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -207,7 +207,7 @@ struct crypto_aead *krb5_prepare_encrypt
 	struct crypto_aead *ci = NULL;
 	int ret = -ENOMEM;
 
-	ci = crypto_alloc_aead(krb5->encrypt_name, 0, 0);
+	ci = crypto_alloc_aead(krb5->encrypt_name, 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(ci)) {
 		ret = PTR_ERR(ci);
 		if (ret == -ENOENT)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Gil Portnoy <[email protected]>

commit 10f293a07f9e10e988b0ae44e2e99c631f5a68e0 upstream.

Commit f580d27e8928 ("ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL") made smb2_cancel() skip a work whose state is KSMBD_WORK_CANCELLED, so its cancel_fn cannot be fired a second time. But KSMBD_WORK has three states (ACTIVE, CANCELLED, CLOSED), and the same freeing producer path is reached for CLOSED too:

SMB2_CLOSE on the locking handle -> set_close_state_blocked_works() sets the deferred work's state to KSMBD_WORK_CLOSED and wakes the smb2_lock() worker. The worker takes the non-ACTIVE early-exit, locks_free_lock()s the file_lock and, because the state is not KSMBD_WORK_CANCELLED, takes the STATUS_RANGE_NOT_LOCKED branch with "goto out2" -- which, like the cancelled branch, skips release_async_work(). The work stays on conn->async_requests with a live cancel_fn = smb2_remove_blocked_lock pointing at the freed file_lock.

A subsequent SMB2_CANCEL for the same AsyncId then passes the KSMBD_WORK_CANCELLED-only guard (its state is KSMBD_WORK_CLOSED), so smb2_cancel() fires cancel_fn again over the freed file_lock -- the same use-after-free fixed, via SMB2_CLOSE instead of a first SMB2_CANCEL:

  BUG: KASAN: slab-use-after-free in __locks_delete_block
    __locks_delete_block
    locks_delete_block
    ksmbd_vfs_posix_lock_unblock
    smb2_remove_blocked_lock
    smb2_cancel                 <- 2nd SMB2_CANCEL fires cancel_fn
    handle_ksmbd_work
  Allocated by ...: locks_alloc_lock <- smb2_lock
  Freed by ...:     locks_free_lock  <- smb2_lock (non-ACTIVE early-exit)
  ... cache file_lock_cache of size 192

Reproduced on mainline 7.1-rc7 (which already contains f580d27e8928) with KASAN by an authenticated SMB client; the double-SMB2_CANCEL control is silent on that kernel, so the splat is attributable to the CLOSE trigger.

Only an ACTIVE deferred work may have its cancel_fn fired: both terminal states (CANCELLED and CLOSED) reach the smb2_lock() early-exit that frees the file_lock and skips release_async_work(). Guard on KSMBD_WORK_ACTIVE so any non-active work is skipped.

---
 fs/smb/server/smb2pdu.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

@@ -7334,14 +7334,14 @@ int smb2_cancel(struct ksmbd_work *work)
 				continue;
 
 			/*
-			 * A cancelled deferred byte-range lock frees its
-			 * file_lock and takes the smb2_lock() early-exit that
-			 * skips release_async_work(), so the work stays on
-			 * conn->async_requests with a live cancel_fn pointing
-			 * at the freed file_lock.  Re-firing it on a second
-			 * SMB2_CANCEL is a use-after-free.
+			 * Only an ACTIVE deferred work may have its cancel_fn
+			 * fired.  A CANCELLED or CLOSED work already took the
+			 * smb2_lock() non-ACTIVE early-exit that frees the
+			 * file_lock and skips release_async_work(), so it is
+			 * still on conn->async_requests with a live cancel_fn
+			 * pointing at the freed file_lock.
 			 */
-			if (iter->state == KSMBD_WORK_CANCELLED)
+			if (iter->state != KSMBD_WORK_ACTIVE)
 				break;
 
 			ksmbd_debug(SMB,

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Zijing Yin <[email protected]>

commit d129c3177d7b1138fd5066fcc63a698b3ba415b0 upstream.

pfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by allocating x->calg and copying only the algorithm name:

	x->calg = kmalloc_obj(*x->calg);
	if (!x->calg) {
		err = -ENOMEM;
		goto out;
	}
	strcpy(x->calg->alg_name, a->name);
	x->props.calgo = sa->sadb_sa_encrypt;

Unlike the authentication (x->aalg) and encryption (x->ealg) branches of the same function, the compression branch never initializes calg->alg_key_len. IPComp carries no key and the allocation only reserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field is left containing uninitialized slab data.

calg->alg_key_len is later used as a length by xfrm_algo_clone() when an IPComp state is cloned during XFRM_MSG_MIGRATE:

	xfrm_state_migrate()
	  xfrm_state_clone_and_setup()
	    x->calg = xfrm_algo_clone(orig->calg);
	      kmemdup(orig, xfrm_alg_len(orig));

where xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With a non-zero garbage alg_key_len, kmemdup() reads past the end of the 68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating it triggers (net-next, KASAN, init_on_alloc=0):

  BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60
  Read of size 4164 at addr ff11000025a74980 by task diag2/9287
  CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1
  Call Trace:
   <TASK>
   dump_stack_lvl+0x10e/0x1f0
   print_report+0xf7/0x600
   kasan_report+0xe4/0x120
   kasan_check_range+0x105/0x1b0
   __asan_memcpy+0x23/0x60
   kmemdup_noprof+0x44/0x60
   xfrm_state_migrate+0x70a/0x1da0
   xfrm_migrate+0x753/0x18a0
   xfrm_do_migrate+0xb47/0xf10
   xfrm_user_rcv_msg+0x411/0xb50
   netlink_rcv_skb+0x158/0x420
   xfrm_netlink_rcv+0x71/0x90
   netlink_unicast+0x584/0x850
   netlink_sendmsg+0x8b0/0xdc0
   ____sys_sendmsg+0x9f7/0xb90
   ___sys_sendmsg+0x134/0x1d0
   __sys_sendmsg+0x16d/0x220
   do_syscall_64+0x116/0x7d0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   </TASK>

  Allocated by task 9287:
   kasan_save_stack+0x33/0x60
   kasan_save_track+0x14/0x30
   __kasan_kmalloc+0xaa/0xb0
   pfkey_add+0x2652/0x2ea0
   pfkey_process+0x6d0/0x830
   pfkey_sendmsg+0x42c/0x850
   __sys_sendto+0x461/0x4b0
   __x64_sys_sendto+0xe0/0x1c0
   do_syscall_64+0x116/0x7d0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

  The buggy address belongs to the object at ff11000025a74980
   which belongs to the cache kmalloc-96 of size 96
  The buggy address is located 0 bytes inside of
   allocated 68-byte region [ff11000025a74980, ff11000025a749c4)

Depending on the uninitialized value the same field can instead request an oversized kmemdup() allocation and make the migration clone fail.

The XFRM netlink path is not affected: verify_one_alg() rejects an XFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via XFRM_MSG_NEWSA is always self-consistent.

Initialize calg->alg_key_len to 0, matching the aalg/ealg branches.

---
 net/key/af_key.c |    1 +
 1 file changed, 1 insertion(+)

@@ -1218,6 +1218,7 @@ static struct xfrm_state * pfkey_msg2xfr
 				goto out;
 			}
 			strcpy(x->calg->alg_name, a->name);
+			x->calg->alg_key_len = 0;
 			x->props.calgo = sa->sadb_sa_encrypt;
 		} else {
 			int keysize = 0;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chi Wang <[email protected]>

commit c9a71daaecb2fb1d8c704545cc0b1c920b9bf5d7 upstream.

Multiple readers access audit_queue.qlen via skb_queue_len() without holding the queue lock or using READ_ONCE(), while kauditd writes to this field via the skb_dequeue() → __skb_unlink() path with WRITE_ONCE() protected by a spinlock. This constitutes data races.

All affected skb_queue_len(&audit_queue) call sites:
- kauditd_thread() wait_event_freezable() condition
- audit_receive_msg() AUDIT_GET handler (s.backlog assignment)
- audit_receive() backlog check
- audit_log_start() backlog check and pr_warn()

KCSAN reports the following conflicting access pattern (one example):
==================================================================

BUG: KCSAN: data-race in audit_log_start / skb_dequeue

write (marked) to 0xffffffff8512ee20 of 4 bytes by task 661 on cpu 57:

 skb_dequeue+0x70/0xf0
 kauditd_send_queue+0x71/0x220
 kauditd_thread+0x1cb/0x430
 kthread+0x1c2/0x210
 ret_from_fork+0x162/0x1a0
 ret_from_fork_asm+0x1a/0x30

read to 0xffffffff8512ee20 of 4 bytes by task 36586 on cpu 1:

 audit_log_start+0x2a0/0x6b0
 audit_core_dumps+0x64/0xa0
 do_coredump+0x14b/0x1260
 get_signal+0xeb2/0xf70
 arch_do_signal_or_restart+0x41/0x170
 exit_to_user_mode_loop+0xa2/0x1c0
 do_syscall_64+0x1a3/0x1c0
 entry_SYSCALL_64_after_hwframe+0x76/0xe0

value changed: 0x00000001 -> 0x00000000
==================================================================

Resolve the race by switching to lockless helper skb_queue_len_lockless(), which internally uses READ_ONCE() and properly pairs with the WRITE_ONCE() write accesses already present on the writer side.

---
 kernel/audit.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

@@ -946,7 +946,7 @@ main_queue:
 		 *       do the multicast send and rotate records from the
 		 *       main queue to the retry/hold queues */
 		wait_event_freezable(kauditd_wait,
-				     (skb_queue_len(&audit_queue) ? 1 : 0));
+				(skb_queue_len_lockless(&audit_queue) ? 1 : 0));
 	}
 
 	return 0;

@@ -1279,7 +1279,7 @@ static int audit_receive_msg(struct sk_b
 		s.rate_limit		   = audit_rate_limit;
 		s.backlog_limit		   = audit_backlog_limit;
 		s.lost			   = atomic_read(&audit_lost);
-		s.backlog		   = skb_queue_len(&audit_queue);
+		s.backlog		   = skb_queue_len_lockless(&audit_queue);
 		s.feature_bitmap	   = AUDIT_FEATURE_BITMAP_ALL;
 		s.backlog_wait_time	   = audit_backlog_wait_time;
 		s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);

@@ -1622,7 +1622,7 @@ static void audit_receive(struct sk_buff
 
 	/* can't block with the ctrl lock, so penalize the sender now */
 	if (audit_backlog_limit &&
-	    (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
+	    (skb_queue_len_lockless(&audit_queue) > audit_backlog_limit)) {
 		DECLARE_WAITQUEUE(wait, current);
 
 		/* wake kauditd to try and flush the queue */

@@ -1928,7 +1928,7 @@ struct audit_buffer *audit_log_start(str
 		long stime = audit_backlog_wait_time;
 
 		while (audit_backlog_limit &&
-		       (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
+			(skb_queue_len_lockless(&audit_queue) > audit_backlog_limit)) {
 			/* wake kauditd to try and flush the queue */
 			wake_up_interruptible(&kauditd_wait);
 

@@ -1948,7 +1948,7 @@ struct audit_buffer *audit_log_start(str
 			} else {
 				if (audit_rate_check() && printk_ratelimit())
 					pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
-						skb_queue_len(&audit_queue),
+						skb_queue_len_lockless(&audit_queue),
 						audit_backlog_limit);
 				audit_log_lost("backlog limit exceeded");
 				return NULL;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marco Elver <[email protected]>

commit b66774b48dd98f07254951f74ea6f513efe7ff8b upstream.

l2cap_chan_timeout() runs asynchronously and accesses chan->conn. If the connection is torn down while the timer is running or pending, chan->conn can be freed, leading to a use-after-free when the timer worker attempts to lock conn->lock:

| BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
| BUG: KASAN: slab-use-after-free in atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:4456 [inline]
| BUG: KASAN: slab-use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:161 [inline]
| BUG: KASAN: slab-use-after-free in mutex_lock+0x4f/0xa0 kernel/locking/mutex.c:318
| Write of size 8 at addr ffff8881298d9550 by task kworker/2:1/83
|
| CPU: 2 UID: 0 PID: 83 Comm: kworker/2:1 Not tainted 7.1.0-rc6-next-20260601-dirty #6 PREEMPT(full)
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
| Workqueue: events l2cap_chan_timeout
| Call Trace:
|  <TASK>
|  instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
|  atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:4456 [inline]
|  __mutex_trylock_fast kernel/locking/mutex.c:161 [inline]
|  mutex_lock+0x4f/0xa0 kernel/locking/mutex.c:318
|  l2cap_chan_timeout+0x5d/0x1b0 net/bluetooth/l2cap_core.c:422
|  process_one_work kernel/workqueue.c:3326 [inline]
|  process_scheduled_works+0x7c8/0xfb0 kernel/workqueue.c:3409
|  worker_thread+0x8a9/0xcf0 kernel/workqueue.c:3490
|  kthread+0x346/0x430 kernel/kthread.c:436
|  ret_from_fork+0x1a3/0x470 arch/x86/kernel/process.c:158
|  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
|  </TASK>
|
| Allocated by task 320:
|  l2cap_conn_add+0xa7/0x820 net/bluetooth/l2cap_core.c:7075
|  l2cap_connect_cfm+0xdb/0xd70 net/bluetooth/l2cap_core.c:7452
|  hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline]
|  hci_remote_features_evt+0x52f/0x9f0 net/bluetooth/hci_event.c:3760
|  hci_event_func net/bluetooth/hci_event.c:7796 [inline]
|  hci_event_packet+0x561/0xa70 net/bluetooth/hci_event.c:7847
|  hci_rx_work+0x370/0x890 net/bluetooth/hci_core.c:4040
|  process_one_work kernel/workqueue.c:3326 [inline]
|  process_scheduled_works+0x7c8/0xfb0 kernel/workqueue.c:3409
|  worker_thread+0x8a9/0xcf0 kernel/workqueue.c:3490
|  kthread+0x346/0x430 kernel/kthread.c:436
|  ret_from_fork+0x1a3/0x470 arch/x86/kernel/process.c:158
|  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
|
| Freed by task 322:
|  hci_disconn_cfm include/net/bluetooth/hci_core.h:2154 [inline]
|  hci_conn_hash_flush+0x101/0x1f0 net/bluetooth/hci_conn.c:2736
|  hci_dev_close_sync+0x889/0xde0 net/bluetooth/hci_sync.c:5405
|  hci_dev_do_close net/bluetooth/hci_core.c:502 [inline]
|  hci_unregister_dev+0x1f7/0x370 net/bluetooth/hci_core.c:2679
|  vhci_release+0x12a/0x180 drivers/bluetooth/hci_vhci.c:690
|  __fput+0x369/0x890 fs/file_table.c:510
|  task_work_run+0x160/0x1d0 kernel/task_work.c:233
|  get_signal+0xf5b/0x1120 kernel/signal.c:2810
|  arch_do_signal_or_restart+0x4d/0x600 arch/x86/kernel/signal.c:337
|  __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
|  exit_to_user_mode_loop+0x85/0x510 kernel/entry/common.c:98
|  do_syscall_64+0x263/0x3d0 arch/x86/entry/syscall_64.c:100
|  entry_SYSCALL_64_after_hwframe+0x77/0x7f
|
| The buggy address belongs to the object at ffff8881298d9400
|  which belongs to the cache kmalloc-512 of size 512
| The buggy address is located 336 bytes inside of
|  freed 512-byte region [ffff8881298d9400, ffff8881298d9600)

Fix it by having chan->conn hold a reference to l2cap_conn (via l2cap_conn_get) when the channel is added to the connection, and releasing it in the channel destructor. This ensures the l2cap_conn remains alive as long as the channel exists.

A new FLAG_DEL channel flag is introduced to indicate that the channel has been deleted from its connection. l2cap_chan_del() atomically sets this flag using test_and_set_bit() instead of setting chan->conn to NULL. All asynchronous workers (l2cap_chan_timeout, l2cap_ack_timeout, l2cap_monitor_timeout, l2cap_retrans_timeout) and l2cap_chan_send() check FLAG_DEL to determine whether the channel has been torn down, rather than testing chan->conn for NULL.

---
 include/net/bluetooth/l2cap.h |    1 +
 net/bluetooth/l2cap_core.c    |   34 ++++++++++++++++++++--------------
 2 files changed, 21 insertions(+), 14 deletions(-)

@@ -748,6 +748,7 @@ enum {
 	FLAG_ECRED_CONN_REQ_SENT,
 	FLAG_PENDING_SECURITY,
 	FLAG_HOLD_HCI_CONN,
+	FLAG_DEL,
 };
 
 /* Lock nesting levels for L2CAP channels. We need these because lockdep

@@ -411,7 +411,7 @@ static void l2cap_chan_timeout(struct wo
 
 	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
 
-	if (!conn) {
+	if (test_bit(FLAG_DEL, &chan->flags)) {
 		l2cap_chan_put(chan);
 		return;
 	}

@@ -422,6 +422,9 @@ static void l2cap_chan_timeout(struct wo
 	 */
 	l2cap_chan_lock(chan);
 
+	if (test_bit(FLAG_DEL, &chan->flags))
+		goto unlock;
+
 	if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
 		reason = ECONNREFUSED;
 	else if (chan->state == BT_CONNECT &&

@@ -434,10 +437,10 @@ static void l2cap_chan_timeout(struct wo
 
 	chan->ops->close(chan);
 
+unlock:
 	l2cap_chan_unlock(chan);
-	l2cap_chan_put(chan);
-
 	mutex_unlock(&conn->lock);
+	l2cap_chan_put(chan);
 }
 
 struct l2cap_chan *l2cap_chan_create(void)

@@ -490,6 +493,9 @@ static void l2cap_chan_destroy(struct kr
 	list_del(&chan->global_l);
 	write_unlock(&chan_list_lock);
 
+	if (chan->conn)
+		l2cap_conn_put(chan->conn);
+
 	kfree(chan);
 }
 

@@ -593,7 +599,7 @@ void __l2cap_chan_add(struct l2cap_conn
 
 	conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
 
-	chan->conn = conn;
+	chan->conn = l2cap_conn_get(conn);
 
 	switch (chan->chan_type) {
 	case L2CAP_CHAN_CONN_ORIENTED:

@@ -648,30 +654,26 @@ void l2cap_chan_add(struct l2cap_conn *c
 
 void l2cap_chan_del(struct l2cap_chan *chan, int err)
 {
-	struct l2cap_conn *conn = chan->conn;
-
 	__clear_chan_timer(chan);
 
-	BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
+	BT_DBG("chan %p, err %d, state %s", chan, err,
 	       state_to_string(chan->state));
 
 	chan->ops->teardown(chan, err);
 
-	if (conn) {
+	if (!test_and_set_bit(FLAG_DEL, &chan->flags)) {
 		/* Delete from channel list */
 		list_del(&chan->list);
 
 		l2cap_chan_put(chan);
 
-		chan->conn = NULL;
-
 		/* Reference was only held for non-fixed channels or
 		 * fixed channels that explicitly requested it using the
 		 * FLAG_HOLD_HCI_CONN flag.
 		 */
 		if (chan->chan_type != L2CAP_CHAN_FIXED ||
 		    test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
-			hci_conn_drop(conn->hcon);
+			hci_conn_drop(chan->conn->hcon);
 	}
 
 	if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))

@@ -1903,7 +1905,7 @@ static void l2cap_monitor_timeout(struct
 
 	l2cap_chan_lock(chan);
 
-	if (!chan->conn) {
+	if (test_bit(FLAG_DEL, &chan->flags)) {
 		l2cap_chan_unlock(chan);
 		l2cap_chan_put(chan);
 		return;

@@ -1924,7 +1926,7 @@ static void l2cap_retrans_timeout(struct
 
 	l2cap_chan_lock(chan);
 
-	if (!chan->conn) {
+	if (test_bit(FLAG_DEL, &chan->flags)) {
 		l2cap_chan_unlock(chan);
 		l2cap_chan_put(chan);
 		return;

@@ -2565,7 +2567,7 @@ int l2cap_chan_send(struct l2cap_chan *c
 	int err;
 	struct sk_buff_head seg_queue;
 
-	if (!chan->conn)
+	if (test_bit(FLAG_DEL, &chan->flags))
 		return -ENOTCONN;
 
 	/* Connectionless channel */

@@ -3160,12 +3162,16 @@ static void l2cap_ack_timeout(struct wor
 
 	l2cap_chan_lock(chan);
 
+	if (test_bit(FLAG_DEL, &chan->flags))
+		goto unlock;
+
 	frames_to_ack = __seq_offset(chan, chan->buffer_seq,
 				     chan->last_acked_seq);
 
 	if (frames_to_ack)
 		l2cap_send_rr_or_rnr(chan, 0);
 
+unlock:
 	l2cap_chan_unlock(chan);
 	l2cap_chan_put(chan);
 }

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Samuel Page <[email protected]>

commit fa85d985f614bc3feb343000f14a1072e99b0df1 upstream.

add_device_complete() runs from the hci_cmd_sync_work kworker, which holds only hci_req_sync_lock and *not* hci_dev_lock. It calls hci_conn_params_lookup() and then dereferences the returned object (params->flags) without taking hci_dev_lock:

	params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr,
					le_addr_type(cp->addr.type));
	...
	device_flags_changed(NULL, hdev, &cp->addr.bdaddr,
			     cp->addr.type, hdev->conn_flags,
			     params ? params->flags : 0);

hci_conn_params_lookup() walks hdev->le_conn_params and is documented to require hdev->lock. A concurrent MGMT_OP_REMOVE_DEVICE (remove_device()), which does run under hci_dev_lock, can call hci_conn_params_free() to list_del() and kfree() the very object the lookup returned, so the subsequent params->flags read touches freed memory [0].

Hold hci_dev_lock() across the hci_conn_params_lookup() and the read of params->flags (and the matching event emission) so the lookup result cannot be freed by a concurrent remove_device() before it is used, honouring the locking contract of hci_conn_params_lookup().

[0]: (trailing page/memory-state dump trimmed)

BUG: KASAN: slab-use-after-free in add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671
Read of size 1 at addr ffff000017ab26c1 by task kworker/u9:8/388

CPU: 1 UID: 0 PID: 388 Comm: kworker/u9:8 Not tainted 7.0.11 #20 PREEMPT
Hardware name: linux,dummy-virt (DT)
Workqueue: hci0 hci_cmd_sync_work
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xb4/0xd4 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x118/0x5d8 mm/kasan/report.c:482
 kasan_report+0xb0/0xf4 mm/kasan/report.c:595
 __asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378
 add_device_complete+0x358/0x3d8 net/bluetooth/mgmt.c:7671
 hci_cmd_sync_work+0x14c/0x240 net/bluetooth/hci_sync.c:334
 process_one_work+0x628/0xd38 kernel/workqueue.c:3289
 process_scheduled_works kernel/workqueue.c:3372 [inline]
 worker_thread+0x7a8/0xac0 kernel/workqueue.c:3453
 kthread+0x39c/0x444 kernel/kthread.c:436
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Allocated by task 3401:
 kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57
 kasan_save_track+0x20/0x3c mm/kasan/common.c:78
 kasan_save_alloc_info+0x40/0x54 mm/kasan/generic.c:570
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xd4/0xd8 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x1b0/0x458 mm/slub.c:5385
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 hci_conn_params_add+0x10c/0x4b0 net/bluetooth/hci_core.c:2279
 hci_conn_params_set net/bluetooth/mgmt.c:5162 [inline]
 add_device+0x5b4/0xa54 net/bluetooth/mgmt.c:7755
 hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline]
 hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0xe0/0x128 net/socket.c:742
 sock_write_iter+0x250/0x390 net/socket.c:1195
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x66c/0xab0 fs/read_write.c:688
 ksys_write+0x1fc/0x24c fs/read_write.c:740
 __do_sys_write fs/read_write.c:751 [inline]
 __se_sys_write fs/read_write.c:748 [inline]
 __arm64_sys_write+0x70/0xa4 fs/read_write.c:748
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151
 el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Freed by task 3740:
 kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57
 kasan_save_track+0x20/0x3c mm/kasan/common.c:78
 kasan_save_free_info+0x4c/0x74 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x88/0xb8 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6170 [inline]
 kfree+0x14c/0x458 mm/slub.c:6488
 hci_conn_params_free+0x288/0x484 net/bluetooth/hci_core.c:2312
 remove_device+0x4b0/0x968 net/bluetooth/mgmt.c:7919
 hci_mgmt_cmd net/bluetooth/hci_sock.c:1721 [inline]
 hci_sock_sendmsg+0x10b4/0x1dd0 net/bluetooth/hci_sock.c:1841
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0xe0/0x128 net/socket.c:742
 sock_write_iter+0x250/0x390 net/socket.c:1195
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x66c/0xab0 fs/read_write.c:688
 ksys_write+0x1fc/0x24c fs/read_write.c:740
 __do_sys_write fs/read_write.c:751 [inline]
 __se_sys_write fs/read_write.c:748 [inline]
 __arm64_sys_write+0x70/0xa4 fs/read_write.c:748
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x84/0x2a8 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xe4/0x294 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x44/0x5c arch/arm64/kernel/syscall.c:151
 el0_svc+0x38/0xac arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0xa0/0xe4 arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

---
 net/bluetooth/mgmt.c |    3 +++
 1 file changed, 3 insertions(+)

@@ -7641,6 +7641,8 @@ static void add_device_complete(struct h
 	if (!err) {
 		struct hci_conn_params *params;
 
+		hci_dev_lock(hdev);
+
 		params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr,
 						le_addr_type(cp->addr.type));
 

@@ -7649,6 +7651,7 @@ static void add_device_complete(struct h
 		device_flags_changed(NULL, hdev, &cp->addr.bdaddr,
 				     cp->addr.type, hdev->conn_flags,
 				     params ? params->flags : 0);
+		hci_dev_unlock(hdev);
 	}
 
 	mgmt_cmd_complete(cmd->sk, hdev->id, MGMT_OP_ADD_DEVICE,

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Runyu Xiao <[email protected]>

commit fa09f08ede3db3050ae16ae1ed92c902d0cada23 upstream.

The etb10 miscdevice uses drvdata->reading as a shared exclusivity gate for userspace buffer access. etb_open() claims that gate with local_cmpxchg(), and etb_release() clears it with local_set().

That gate is shared per-device state rather than CPU-local state. A running system can reach it whenever /dev/<etb> is opened, closed, and reopened by different tasks while the device remains registered, so the same drvdata->reading variable may be claimed on one CPU and later cleared on another.

This code used to use atomic_t for the same gate, but commit 27b10da8fff2 ("coresight: etb10: moving to local atomic operations") changed it to local_t even though the access pattern remained cross-task and cross-CPU. Restore atomic_t together with atomic_cmpxchg() and atomic_set() so the exclusivity gate again uses a primitive intended for shared state.

The issue was found on Linux v6.18.21 by our static analysis tool while scanning surviving local_t-on-shared-state sites, and then manually reviewed against the live etb10 file-op path.

It was runtime-validated with a reproducible QEMU no-device KCSAN PoC that kept the same report-local contract:

1. use one shared struct etb_drvdata carrier and its

     drvdata->reading gate;
  2. call etb_open() and etb_release() sequentially on that gate to
     confirm the original claim/clear path;
  3. bind the open side to CPU0 and the release side to CPU1 for the
     same gate to show cross-CPU ownership;

4. run bound workers that repeatedly race etb_open() and etb_release() on the same gate until KCSAN reports a target hit.

The harness recorded:

L1 passed open=1 release=1
reading_after_open=1 reading_after_release=0
L2 passed open_cpu=0 release_cpu=1
cross_cpu_release=1 reading_after=0 open_ret=0

Representative KCSAN excerpt from the no-device validation run:

  BUG: KCSAN: data-race in etb_open.constprop.0.isra.0 [vuln_msv]

write to 0xffffffffc0003810 of 4 bytes by task 216 on cpu 1:

   etb_open.constprop.0.isra.0+0x38/0x80 [vuln_msv]
   l3_worker_thread_fn+0x4f/0xf0 [vuln_msv]
   kthread+0x17e/0x1c0
   ret_from_fork+0x22/0x30

read to 0xffffffffc0003810 of 4 bytes by task 215 on cpu 0:

   etb_open.constprop.0.isra.0+0x18/0x80 [vuln_msv]
   l3_worker_thread_fn+0x4f/0xf0 [vuln_msv]
   kthread+0x17e/0x1c0
   ret_from_fork+0x22/0x30

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:

  CPU: 0 PID: 215 Comm: etb10_l3_a Tainted: G           O       6.1.66 #2

This no-device harness is not a real ETB10 hardware end-to-end run, but it preserves the same shared drvdata->reading gate and the same etb_open()/etb_release() claim/clear contract. No real ETB10 hardware was available for runtime testing.

Build-tested with:
make olddefconfig
make -j"$(nproc)" drivers/hwtracing/coresight/coresight-etb10.o

---
 drivers/hwtracing/coresight/coresight-etb10.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -85,7 +85,7 @@ struct etb_drvdata {
 	struct coresight_device	*csdev;
 	struct miscdevice	miscdev;
 	raw_spinlock_t		spinlock;
-	local_t			reading;
+	atomic_t		reading;
 	pid_t			pid;
 	u8			*buf;
 	u32			buffer_depth;

@@ -603,7 +603,7 @@ static int etb_open(struct inode *inode,
 	struct etb_drvdata *drvdata = container_of(file->private_data,
 						   struct etb_drvdata, miscdev);
 
-	if (local_cmpxchg(&drvdata->reading, 0, 1))
+	if (atomic_cmpxchg(&drvdata->reading, 0, 1))
 		return -EBUSY;
 
 	dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__);

@@ -641,7 +641,7 @@ static int etb_release(struct inode *ino
 {
 	struct etb_drvdata *drvdata = container_of(file->private_data,
 						   struct etb_drvdata, miscdev);
-	local_set(&drvdata->reading, 0);
+	atomic_set(&drvdata->reading, 0);
 
 	dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__);
 	return 0;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <[email protected]>

commit b81dde13cc163450dcb402dcc915ef13ba241e01 upstream.

syzbot reported a puzzling splat:

   WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20

stub_timer() is installed as timer callback function in hrtimer_fixup_assert_init(), which is invoked when debug_object_assert_init() can't find a shadow object. In that case debug objects emits a warning about it before invoking the fixup.

Though the provided console log lacks this warning and instead has the following a few seconds before the splat:

ODEBUG: Out of memory. ODEBUG disabled

So the object was looked up in debug_object_assert_init() and the lookup failed due a concurrent out of memory situation which disabled debug objects and freed the shadow objects:

debug_object_assert_init()

        if (!debug_objects_enabled)
        	return;                         obj = alloc();
                				if (!obj) {
							// Out of memory
                                                	debug_objects_enabled = false;
                                                        free_objects();
        obj = lookup_or_alloc();

        // The lookup failed because the other side
        // removed the objects, so this returns
        // an error code as the object in question
        // is not statically initialized

	if (!IS_ERR_OR_NULL(obj))
        	return;
        if (!obj) {
        	debug_oom();
                return;
        }

        print(...)
           if (!debug_objects_enabled)
                return;

        fixup(...)

The debug object splat is skipped because debug_objects_enabled is false, but the fixup callback is invoked unconditionally, which makes the timer disfunctional.

This is only a problem in debug_object_assert_init() and debug_object_activate() as both have to handle statically initialized objects and therefore must handle the error pointer return case gracefully. All other places only handle the found/not found case and the NULL pointer return is a signal for OOM. Otherwise they get a valid shadow object.

Plug the hole by checking whether debug objects are still enabled before invoking the print and fixup function in those two places.

---
 lib/debugobjects.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

@@ -894,6 +894,14 @@ int debug_object_activate(void *addr, co
 	}
 
 	raw_spin_unlock_irqrestore(&db->lock, flags);
+
+	/*
+	 * lookup_object_or_alloc() might have raced with a concurrent
+	 * allocation failure which disabled debug objects.
+	 */
+	if (!debug_objects_enabled)
+		return 0;
+
 	debug_print_object(&o, "activate");
 
 	switch (o.state) {

@@ -1071,6 +1079,15 @@ void debug_object_assert_init(void *addr
 		return;
 	}
 
+	/*
+	 * lookup_object_or_alloc() might have raced with a concurrent
+	 * allocation failure which disabled debug objects. Don't run the fixup
+	 * as it might turn a valid object useless. See for example
+	 * hrtimer_fixup_assert_init().
+	 */
+	if (!debug_objects_enabled)
+		return;
+
 	/* Object is neither tracked nor static. It's not initialized. */
 	debug_print_object(&o, "assert_init");
 	debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Yunpeng Tian <[email protected]>

commit 57382ec6ac63b63dce2789e835fded28b698ae79 upstream.

In the analysis pass of $LogFile journal replay, log_replay() copies LCNs from each action log record into an existing Dirty Page Table (DPT) entry without bounding the destination index. A crafted NTFS image with DPT entry lcns_follow=1 and an action log record with lcns_follow=2 produces a kernel slab out-of-bounds write at mount time:

  BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60
  Write of size 8 at addr ffff8880095e1040 by task mount

Two attacker-controlled fields can drive j+i past the allocated page_lcns[] array:

1. dp->lcns_follow (capacity) can be smaller than lrh->lcns_follow.
2. lrh->target_vcn may be smaller than dp->vcn, making the u64 subtraction wrap to a huge size_t.

Validate target VCN delta and per-record LCN count against the DPT entry capacity, bail via the existing out: cleanup label with -EINVAL.

This mirrors the bounds-check pattern added in commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") and commit 0ca0485e4b2e ("fs/ntfs3: validate rec->used in journal-replay file record check").

---
 fs/ntfs3/fslog.c |   20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

@@ -4546,11 +4546,21 @@ copy_lcns:
 		 * whole routine a loop, case Lcns do not fit below.
 		 */
 		t16 = le16_to_cpu(lrh->lcns_follow);
-		for (i = 0; i < t16; i++) {
-			size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -
-					    le64_to_cpu(dp->vcn));
-			dp->page_lcns[j + i] = lrh->page_lcns[i];
-		}
+                t32 = le32_to_cpu(dp->lcns_follow);
+                if (le64_to_cpu(lrh->target_vcn) < le64_to_cpu(dp->vcn)) {
+                        err = -EINVAL;
+                        goto out;
+                }
+
+                for (i = 0; i < t16; i++) {
+                        size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -
+                                            le64_to_cpu(dp->vcn));
+                        if (j >= t32 || i >= t32 - j) {
+                                err = -EINVAL;
+                                goto out;
+                        }
+                        dp->page_lcns[j + i] = lrh->page_lcns[i];
+                }
 
 		goto next_log_record_analyze;
 

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Koichiro Den <[email protected]>

commit 4dcddc1c794d1c65eda68f1f8dd04a0fecc0870f upstream.

ntb_epf_vec_isr() calls pci_irq_vector() in hardirq context to derive the vector number. pci_irq_vector() calls msi_get_virq() that takes a mutex and can therefore trigger "scheduling while atomic" splats:

  BUG: scheduling while atomic: kworker/u33:0/55/0x00010001
  ...
  Call trace:
   ...
   schedule+0x38/0x110
   schedule_preempt_disabled+0x28/0x50
   __mutex_lock.constprop.0+0x848/0x908
   __mutex_lock_slowpath+0x18/0x30
   mutex_lock+0x4c/0x60
   msi_domain_get_virq+0xe8/0x138
   pci_irq_vector+0x2c/0x60
   ntb_epf_vec_isr+0x28/0x120 [ntb_hw_epf]
   __handle_irq_event_percpu+0x70/0x3a8
   handle_irq_event+0x48/0x100
   handle_edge_irq+0x100/0x1c8
   ...

Cache the Linux IRQ number for vector 0 when vectors are allocated and use it as a base in the ISR. Running the ISR in a threaded IRQ handler would also avoid the problem, but that would be unnecessary here.

---
 drivers/ntb/hw/epf/ntb_hw_epf.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

@@ -92,6 +92,7 @@ struct ntb_epf_dev {
 
 	int db_val;
 	u64 db_valid_mask;
+	int irq_base;
 };
 
 #define ntb_ndev(__ntb) container_of(__ntb, struct ntb_epf_dev, ntb)

@@ -318,7 +319,7 @@ static irqreturn_t ntb_epf_vec_isr(int i
 	struct ntb_epf_dev *ndev = dev;
 	int irq_no;
 
-	irq_no = irq - pci_irq_vector(ndev->ntb.pdev, 0);
+	irq_no = irq - ndev->irq_base;
 	ndev->db_val = irq_no + 1;
 
 	if (irq_no == 0)

@@ -350,6 +351,7 @@ static int ntb_epf_init_isr(struct ntb_e
 		argument &= ~MSIX_ENABLE;
 	}
 
+	ndev->irq_base = pci_irq_vector(pdev, 0);
 	for (i = 0; i < irq; i++) {
 		ret = request_irq(pci_irq_vector(pdev, i), ntb_epf_vec_isr,
 				  0, "ntb_epf", ndev);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Runyu Xiao <[email protected]>

commit 90f0109019e6817eb40a486671b7722d1544ae29 upstream.

sprd_eic_irq_unmask() enables the GPIO IRQ and then updates controller state through sprd_eic_update(), which takes sprd_eic->lock with spin_lock_irqsave(). The callback can be reached from irq_startup() while setting up a requested IRQ. That path is not sleepable, but on PREEMPT_RT a regular spinlock_t becomes a sleeping lock.

This issue was found by our static analysis tool and then manually reviewed against the current tree.

The grounded PoC kept the request_threaded_irq() -> __setup_irq() -> irq_startup() -> sprd_eic_irq_unmask() -> sprd_eic_update() carrier and used the original spin_lock_irqsave(&sprd_eic->lock) edge. Lockdep reported:

  BUG: sleeping function called from invalid context
  hardirqs last disabled at ... __setup_irq.constprop.0 ... [vuln_msv]
  sprd_rt_spin_lock_irqsave+0x1c/0x30 [vuln_msv]
  sprd_eic_update.constprop.0+0x48/0x90 [vuln_msv]
  sprd_eic_irq_unmask.constprop.0+0x35/0x50 [vuln_msv]
  __setup_irq.constprop.0+0xd/0x30 [vuln_msv]

Convert the Spreadtrum EIC controller lock to raw_spinlock_t. The locked section only serializes MMIO register updates and does not contain sleepable operations, so keeping it non-sleeping is appropriate for the irqchip callbacks.

---
 drivers/gpio/gpio-eic-sprd.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

@@ -95,7 +95,7 @@ struct sprd_eic {
 	struct notifier_block irq_nb;
 	void __iomem *base[SPRD_EIC_MAX_BANK];
 	enum sprd_eic_type type;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	int irq;
 };
 

@@ -149,7 +149,7 @@ static void sprd_eic_update(struct gpio_
 	unsigned long flags;
 	u32 tmp;
 
-	spin_lock_irqsave(&sprd_eic->lock, flags);
+	raw_spin_lock_irqsave(&sprd_eic->lock, flags);
 	tmp = readl_relaxed(base + reg);
 
 	if (val)

@@ -158,7 +158,7 @@ static void sprd_eic_update(struct gpio_
 		tmp &= ~BIT(SPRD_EIC_BIT(offset));
 
 	writel_relaxed(tmp, base + reg);
-	spin_unlock_irqrestore(&sprd_eic->lock, flags);
+	raw_spin_unlock_irqrestore(&sprd_eic->lock, flags);
 }
 
 static int sprd_eic_read(struct gpio_chip *chip, unsigned int offset, u16 reg)

@@ -628,7 +628,7 @@ static int sprd_eic_probe(struct platfor
 	if (!sprd_eic)
 		return -ENOMEM;
 
-	spin_lock_init(&sprd_eic->lock);
+	raw_spin_lock_init(&sprd_eic->lock);
 	sprd_eic->type = pdata->type;
 
 	sprd_eic->irq = platform_get_irq(pdev, 0);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Runyu Xiao <[email protected]>

commit 286533cb14a3c8a8bd39ff64ea2fc8e1aa0f638b upstream.

sch_irq_unmask() enables the GPIO IRQ and then updates the controller state through sch_irq_mask_unmask(), which takes sch->lock with spin_lock_irqsave(). The callback can be reached from irq_startup() while setting up a requested IRQ. That path is not sleepable, but on PREEMPT_RT a regular spinlock_t becomes a sleeping lock.

This issue was found by our static analysis tool and then manually reviewed against the current tree.

The grounded PoC kept the request_threaded_irq() -> __setup_irq() -> irq_startup() -> sch_irq_unmask() -> sch_irq_mask_unmask() carrier and used the original spin_lock_irqsave(&sch->lock) edge. Lockdep reported:

  BUG: sleeping function called from invalid context
  hardirqs last disabled at ... __setup_irq.constprop.0 ... [vuln_msv]
  sch_rt_spin_lock_irqsave+0x1c/0x30 [vuln_msv]
  sch_irq_mask_unmask.constprop.0+0x31/0x70 [vuln_msv]
  __setup_irq.constprop.0+0xd/0x30 [vuln_msv]

Convert the SCH controller lock to raw_spinlock_t. The same lock is also used by the GPIO direction and value callbacks, but those critical sections only update MMIO-backed GPIO registers and do not contain sleepable operations. Keeping this register lock non-sleeping is therefore appropriate for the irqchip callbacks and does not change the GPIO-side locking contract.

---
 drivers/gpio/gpio-sch.c |   32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

@@ -39,7 +39,7 @@
 struct sch_gpio {
 	struct gpio_chip chip;
 	void __iomem *regs;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	unsigned short resume_base;
 
 	/* GPE handling */

@@ -104,9 +104,9 @@ static int sch_gpio_direction_in(struct
 	struct sch_gpio *sch = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 	sch_gpio_reg_set(sch, gpio_num, GIO, 1);
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 	return 0;
 }
 

@@ -122,9 +122,9 @@ static int sch_gpio_set(struct gpio_chip
 	struct sch_gpio *sch = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 	sch_gpio_reg_set(sch, gpio_num, GLV, val);
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 
 	return 0;
 }

@@ -135,9 +135,9 @@ static int sch_gpio_direction_out(struct
 	struct sch_gpio *sch = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 	sch_gpio_reg_set(sch, gpio_num, GIO, 0);
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 
 	/*
 	 * according to the datasheet, writing to the level register has no

@@ -196,14 +196,14 @@ static int sch_irq_type(struct irq_data
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 
 	sch_gpio_reg_set(sch, gpio_num, GTPE, rising);
 	sch_gpio_reg_set(sch, gpio_num, GTNE, falling);
 
 	irq_set_handler_locked(d, handle_edge_irq);
 
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 
 	return 0;
 }

@@ -215,9 +215,9 @@ static void sch_irq_ack(struct irq_data
 	irq_hw_number_t gpio_num = irqd_to_hwirq(d);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 	sch_gpio_reg_set(sch, gpio_num, GTS, 1);
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 }
 
 static void sch_irq_mask_unmask(struct gpio_chip *gc, irq_hw_number_t gpio_num, int val)

@@ -225,9 +225,9 @@ static void sch_irq_mask_unmask(struct g
 	struct sch_gpio *sch = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 	sch_gpio_reg_set(sch, gpio_num, GGPE, val);
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 }
 
 static void sch_irq_mask(struct irq_data *d)

@@ -268,12 +268,12 @@ static u32 sch_gpio_gpe_handler(acpi_han
 	int offset;
 	u32 ret;
 
-	spin_lock_irqsave(&sch->lock, flags);
+	raw_spin_lock_irqsave(&sch->lock, flags);
 
 	core_status = ioread32(sch->regs + CORE_BANK_OFFSET + GTS);
 	resume_status = ioread32(sch->regs + RESUME_BANK_OFFSET + GTS);
 
-	spin_unlock_irqrestore(&sch->lock, flags);
+	raw_spin_unlock_irqrestore(&sch->lock, flags);
 
 	pending = (resume_status << sch->resume_base) | core_status;
 	for_each_set_bit(offset, &pending, sch->chip.ngpio)

@@ -343,7 +343,7 @@ static int sch_gpio_probe(struct platfor
 
 	sch->regs = regs;
 
-	spin_lock_init(&sch->lock);
+	raw_spin_lock_init(&sch->lock);
 	sch->chip = sch_gpio_chip;
 	sch->chip.label = dev_name(dev);
 	sch->chip.parent = dev;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vasileios Almpanis <[email protected]>

commit 2564ca2e31bd8ee8348362941af2ee4671e487ca upstream.

NOP file-acquisition support choses between a fixed (registered) file and a normal fget()'d file based on its own IORING_NOP_FIXED_FILE flag in sqe->nop_flags. However, a request's REQ_F_FIXED_FILE is set independently from the generic IOSQE_FIXED_FILE sqe flag during request init, before the issue handler runs.

If a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is set) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path and grabs a real reference via io_file_get_normal(). On completion, io_put_file() only drops the reference when REQ_F_FIXED_FILE is clear, so the fget()'d file is never released and leaks:

  BUG: memory leak
  unreferenced object 0xffff88800f42c240 (size 176):
    kmem_cache_alloc_noprof+0x358/0x440
    alloc_empty_file+0x57/0x180
    path_openat+0x44/0x1e50
    do_file_open+0x121/0x200
    do_sys_openat2+0xa7/0x150
    __x64_sys_openat+0x82/0xf0

Decide between fixed and normal file acquisition from REQ_F_FIXED_FILE, the same way io_assign_file() does for every other opcode, and fold IORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.

---
 io_uring/nop.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

@@ -41,6 +41,8 @@ int io_nop_prep(struct io_kiocb *req, co
 		nop->fd = READ_ONCE(sqe->fd);
 	else
 		nop->fd = -1;
+	if (nop->flags & IORING_NOP_FIXED_FILE)
+		req->flags |= REQ_F_FIXED_FILE;
 	if (nop->flags & IORING_NOP_FIXED_BUFFER)
 		req->buf_index = READ_ONCE(sqe->buf_index);
 	if (nop->flags & IORING_NOP_CQE32) {

@@ -60,12 +62,10 @@ int io_nop(struct io_kiocb *req, unsigne
 	int ret = nop->result;
 
 	if (nop->flags & IORING_NOP_FILE) {
-		if (nop->flags & IORING_NOP_FIXED_FILE) {
+		if (req->flags & REQ_F_FIXED_FILE)
 			req->file = io_file_get_fixed(req, nop->fd, issue_flags);
-			req->flags |= REQ_F_FIXED_FILE;
-		} else {
+		else
 			req->file = io_file_get_normal(req, nop->fd);
-		}
 		if (!req->file) {
 			ret = -EBADF;
 			goto done;

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Runyu Xiao <[email protected]>

commit 29bef9934b2521f787bb15dd1985d4c0d12ae02a upstream.

commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early.

io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun.

Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time.

---
 io_uring/io-wq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -601,7 +601,6 @@ static void io_worker_handle_work(struct
 	struct io_wq *wq = worker->wq;
 
 	do {
-		bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
 		struct io_wq_work *work;
 
 		/*

@@ -637,6 +636,7 @@ static void io_worker_handle_work(struct
 
 		/* handle a whole dependent link */
 		do {
+			bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
 			struct io_wq_work *next_hashed, *linked;
 			unsigned int work_flags = atomic_read(&work->flags);
 			unsigned int hash = __io_wq_is_hashed(work_flags)

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Wigham <[email protected]>

commit c554246ff4c68abf71b61a89c6e39d3cf94f523e upstream.

A partial read will store the completed byte count in io->bytes_done. The regular completion path applies io_fixup_rw_res() so that, when the following operation reaches EOF, the number of bytes already read is returned.

The iopoll completion path does not apply this fixup to the return value and can return zero instead.

Use the fixup result when updating the CQE, and the raw result for the reissue check.

---
 io_uring/rw.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

@@ -611,15 +611,15 @@ static void io_complete_rw_iopoll(struct
 {
 	struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb);
 	struct io_kiocb *req = cmd_to_io_kiocb(rw);
+	int final_res = io_fixup_rw_res(req, res);
 
 	if (kiocb->ki_flags & IOCB_WRITE)
 		io_req_end_write(req);
-	if (unlikely(res != req->cqe.res)) {
-		if (res == -EAGAIN && io_rw_should_reissue(req))
-			req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE;
-		else
-			req->cqe.res = res;
-	}
+
+	if (res == -EAGAIN && io_rw_should_reissue(req))
+		req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE;
+	else if (unlikely(final_res != req->cqe.res))
+		req->cqe.res = final_res;
 
 	/* order with io_iopoll_complete() checking ->iopoll_completed */
 	smp_store_release(&req->iopoll_completed, 1);

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Breno Leitao <[email protected]>

commit 45f1458a85017a023f138b22ac5c76abd477db42 upstream.

There is a use-after-free error on netpoll, which is clearly detected by KASAN.

      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80
      Read of size 1 at addr ... by task kworker/9:1
      Workqueue: events queue_process
      Call Trace:
       skb_dequeue+0x1e/0xb0
       queue_process+0x2c/0x600
       process_scheduled_works+0x4b6/0x850
       worker_thread+0x414/0x5a0
      Allocated by task 242:
       __netpoll_setup+0x201/0x4a0
       netpoll_setup+0x249/0x550
       enabled_store+0x32f/0x380
      Freed by task 0:
       kfree+0x1b7/0x540
       rcu_core+0x3f8/0x7a0

The problem happens when there is a pending TX worker running in parallel with the cleanup path.

This is what happens on netpoll shutdown path:

1) __netpoll_cleanup() is called
2) set dev->npinfo to NULL
3) call_rcu() with rcu_cleanup_netpoll_info()
3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with
cancel_delayed_work(), but doesn't wait for the worker to finish
4) and kfree(npinfo);

Because 3.1) doesn't really cancel the work, as the comment says "we can't call cancel_delayed_work_sync here, as we are in softirq", the TX worker can run after 4).

Tl;DR: queue_process() is not an RCU reader, it reaches npinfo through the work item via container_of().

Use disable_delayed_work_sync() to ensure the worker is completely stopped and prevent any future re-arming attempts. Once npinfo is set to NULL, senders will bail out and not queue new work. The disable flag ensures any in-flight re-arming attempts also fail silently.

In the future, we can do the cleanup inline here without needing the npinfo->rcu rcu_head, but that is net-next material.

---
 net/core/netpoll.c |    9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

@@ -812,14 +812,6 @@ static void rcu_cleanup_netpoll_info(str
 			container_of(rcu_head, struct netpoll_info, rcu);
 
 	skb_queue_purge(&npinfo->txq);
-
-	/* we can't call cancel_delayed_work_sync here, as we are in softirq */
-	cancel_delayed_work(&npinfo->tx_work);
-
-	/* clean after last, unfinished work */
-	__skb_queue_purge(&npinfo->txq);
-	/* now cancel it again */
-	cancel_delayed_work(&npinfo->tx_work);
 	kfree(npinfo);
 }
 

@@ -843,6 +835,7 @@ static void __netpoll_cleanup(struct net
 			ops->ndo_netpoll_cleanup(np->dev);
 
 		RCU_INIT_POINTER(np->dev->npinfo, NULL);
+		disable_delayed_work_sync(&npinfo->tx_work);
 		call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
 	}
 

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Yuyang Huang <[email protected]>