Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C079436BD3 for ; Wed, 29 Jul 2026 13:07:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785330427; cv=none; b=Tl1GWxB+YjGUJ2UVw/rqM9yMyDMkjh7gitGBM1Vc/mrOnGrUfe/T/X7BF0nL+XJUeaK0NeKqIX0ksHkucEbeZrGzRjfK0oHhex35j0TPSko/3VbBrfv3Bn9+I4Jj5ViItTUwgTRKf7bwxK+4KNgb7hMBBVn47DQNBfYUFRNqe+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785330427; c=relaxed/simple; bh=FVxffVxswSPLyzDRbQQJR1CCmR51XdQUz6GcXjU5Eks=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=ciWhNN/4Sr06xxyWDgtjN2MfOgs591SU2I3q7jIx2zYDswxaRSmbwBOxYOUmai9yeXy1mdA7BQYEVyJltx/pXqU9oCMFion5Hpk/qdBhX263y0JETcxbE7F1eleA93aISorTC5CeWCmmpKGYdTO3BIZDVrJvv4qJuPAKJYnHsXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bxl2aMzk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bxl2aMzk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9AB71F000E9; Wed, 29 Jul 2026 13:07:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785330425; bh=RoJPdIGGOwa4qoSYaBecUqAzbVDvuvkOCECO+TlgyH8=; h=Subject:To:Cc:From:Date; b=bxl2aMzkZ/HxBtRsym9Xr6yhz9O6iMju7kPmJv7Gi8aChVfeaE/6LyxstIarxas0a 79wLnebGN3Fm1sJJOYhy/SHuvludMpLVMyQO0Iu05V9InbElScx7cwoYecSFX5raDu xFRTkHhQV7HCJvmKWlrCRCVegaOMTKgZtXEt9vU4= Subject: FAILED: patch "[PATCH] wifi: brcmfmac: drain bus_reset work on device removal" failed to apply to 6.18-stable tree To: fanwu01@zju.edu.cn,arend.vanspriel@broadcom.com,johannes.berg@intel.com Cc: From: Date: Wed, 29 Jul 2026 15:06:51 +0200 Message-ID: <2026072951-caring-silicon-be2d@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x 43b25879f004c98defa2776bedc6ca4763c51945 # git commit -s git send-email --to '' --in-reply-to '2026072951-caring-silicon-be2d@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 43b25879f004c98defa2776bedc6ca4763c51945 Mon Sep 17 00:00:00 2001 From: Fan Wu Date: Sat, 18 Jul 2026 02:43:53 +0000 Subject: [PATCH] wifi: brcmfmac: drain bus_reset work on device removal brcmf_fw_crashed() and the debugfs "reset" entry both schedule drvr->bus_reset, whose callback recovers drvr through container_of() and dereferences it. The removal path frees drvr (brcmf_free -> wiphy_free) without draining the work, so a bus_reset callback pending or running during removal can outlive drvr. Cancellation cannot live in brcmf_detach() or brcmf_free(): the work callback reaches teardown through the bus .reset op (PCIe brcmf_pcie_reset -> brcmf_detach; SDIO brcmf_sdio_bus_reset -> brcmf_sdiod_remove -> brcmf_free), so cancelling there would wait for the running work and deadlock. Add a per-bus mutex (bus_reset_lock) and route all arming through brcmf_bus_schedule_reset(), which under the lock skips when the bus is marked removing. Each bus remove entry calls brcmf_bus_cancel_reset_work(), which under the same lock sets removing and cancels the work. Holding the mutex across cancel_work_sync() makes the set-removing + drain step atomic. Every producer reaches the arming path from process context -- the PCIe firmware-halt notification runs in the threaded IRQ handler (brcmf_pcie_isr_thread) and the SDIO hostmail path runs from the data workqueue -- so the mutex is taken only in sleepable contexts. Where applicable the remove entry first stops the firmware-crash producer: on PCIe mask the mailbox and synchronize_irq; on SDIO unregister the bus interrupt and cancel the data worker, which also reports firmware halts through brcmf_fw_crashed(). The mutex is initialized at bus allocation. The SDIO suspend power-off path frees drvr through the same brcmf_sdiod_remove() and takes the same lock; resume re-allows the work only on a successful re-probe. Also guard brcmf_fw_crashed() against a NULL bus_if/drvr: it can fire before brcmf_attach() wires up drvr, and it dereferences drvr (bphy_err/brcmf_dev_coredump) before reaching the arming gate. The bus_reset work is shared across buses, so the drain is applied to every remove path: PCIe (the .reset op introduced by the Fixes commit), SDIO (arms the same work through brcmf_fw_crashed()), and USB (via the debugfs "reset" entry). cancel_work_sync() drains a running or pending bus_reset work item before removal frees drvr, and patch 1/2 makes the scratch-buffer release safe when reset teardown has already released those DMA buffers. This patch fixes the lifetime of the bus_reset work item itself. It does not attempt to address the separate, pre-existing lifetime of the asynchronous firmware completion started by the PCIe reset path. That callback needs its own lifetime/ownership protocol and is being tracked separately. This issue was found by an in-house static analysis tool. Fixes: 4684997d9eea ("brcmfmac: reset PCIe bus on a firmware crash") Cc: stable@vger.kernel.org Signed-off-by: Fan Wu Assisted-by: Codex:gpt-5.6 Acked-by: Arend van Spriel Link: https://patch.msgid.link/20260718024353.3147201-3-fanwu01@zju.edu.cn Signed-off-by: Johannes Berg diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c index d24b80e492e0..ec487c6f2e38 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c @@ -1069,6 +1069,7 @@ static int brcmf_ops_sdio_probe(struct sdio_func *func, bus_if = kzalloc_obj(*bus_if); if (!bus_if) return -ENOMEM; + mutex_init(&bus_if->bus_reset_lock); sdiodev = kzalloc_obj(*sdiodev); if (!sdiodev) { kfree(bus_if); @@ -1130,6 +1131,14 @@ static void brcmf_ops_sdio_remove(struct sdio_func *func) if (func->num != 1) return; + /* Drain bus_reset before the shared brcmf_sdiod_remove() + * teardown, which the SDIO reset callback also reaches. The + * data worker can arm bus_reset via brcmf_fw_crashed(); cancel + * it first. + */ + brcmf_sdio_cancel_datawork(sdiodev->bus); + brcmf_bus_cancel_reset_work(bus_if); + /* only proceed with rest of cleanup if func 1 */ brcmf_sdiod_remove(sdiodev); @@ -1204,6 +1213,8 @@ static int brcmf_ops_sdio_suspend(struct device *dev) } else { /* power will be cut so remove device, probe again in resume */ brcmf_sdiod_intr_unregister(sdiodev); + brcmf_sdio_cancel_datawork(sdiodev->bus); + brcmf_bus_cancel_reset_work(bus_if); ret = brcmf_sdiod_remove(sdiodev); if (ret) brcmf_err("Failed to remove device on suspend\n"); @@ -1229,6 +1240,8 @@ static int brcmf_ops_sdio_resume(struct device *dev) ret = brcmf_sdiod_probe(sdiodev); if (ret) brcmf_err("Failed to probe device on resume\n"); + else + brcmf_bus_allow_reset_work(bus_if); } else { if (sdiodev->wowl_enabled && sdiodev->settings->bus.sdio.oob_irq_supported) disable_irq_wake(sdiodev->settings->bus.sdio.oob_irq_nr); diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h index fe31051a9e11..9371c1489948 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h @@ -9,6 +9,7 @@ #include #include #include +#include #include "debug.h" /* IDs of the 6 default common rings of msgbuf protocol */ @@ -179,6 +180,8 @@ struct brcmf_bus { enum brcmf_fwvendor fwvid; bool always_use_fws_queue; bool wowl_supported; + bool removing; /* device removal in progress; quiesce async work */ + struct mutex bus_reset_lock; const struct brcmf_bus_ops *ops; struct brcmf_bus_msgbuf *msgbuf; @@ -186,6 +189,9 @@ struct brcmf_bus { struct list_head list; }; +void brcmf_bus_cancel_reset_work(struct brcmf_bus *bus_if); +void brcmf_bus_allow_reset_work(struct brcmf_bus *bus_if); + /* * callback wrappers */ diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c index ec170647800d..dad6f4563d14 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c @@ -1167,6 +1167,35 @@ static int brcmf_revinfo_read(struct seq_file *s, void *data) return 0; } +/* + * Serialize arming from debugfs reset and brcmf_fw_crashed() against + * teardown. The remove path sets ->removing and drains the work while + * holding bus_reset_lock, so a racing armer is either drained or skips it. + */ +static void brcmf_bus_schedule_reset(struct brcmf_bus *bus_if) +{ + mutex_lock(&bus_if->bus_reset_lock); + if (bus_if->drvr && bus_if->drvr->bus_reset.func && !bus_if->removing) + schedule_work(&bus_if->drvr->bus_reset); + mutex_unlock(&bus_if->bus_reset_lock); +} + +void brcmf_bus_cancel_reset_work(struct brcmf_bus *bus_if) +{ + mutex_lock(&bus_if->bus_reset_lock); + bus_if->removing = true; + if (bus_if->drvr) + cancel_work_sync(&bus_if->drvr->bus_reset); + mutex_unlock(&bus_if->bus_reset_lock); +} + +void brcmf_bus_allow_reset_work(struct brcmf_bus *bus_if) +{ + mutex_lock(&bus_if->bus_reset_lock); + bus_if->removing = false; + mutex_unlock(&bus_if->bus_reset_lock); +} + static void brcmf_core_bus_reset(struct work_struct *work) { struct brcmf_pub *drvr = container_of(work, struct brcmf_pub, @@ -1187,7 +1216,7 @@ static ssize_t bus_reset_write(struct file *file, const char __user *user_buf, if (value != 1) return -EINVAL; - schedule_work(&drvr->bus_reset); + brcmf_bus_schedule_reset(drvr->bus_if); return count; } @@ -1417,14 +1446,23 @@ void brcmf_dev_coredump(struct device *dev) void brcmf_fw_crashed(struct device *dev) { struct brcmf_bus *bus_if = dev_get_drvdata(dev); - struct brcmf_pub *drvr = bus_if->drvr; + struct brcmf_pub *drvr; + + /* May fire before brcmf_attach() wires up drvr, or after removal + * has cleared it; guard the derefs below (and the arming gate in + * brcmf_bus_schedule_reset() already checks drvr/->removing). + */ + if (!bus_if) + return; + drvr = bus_if->drvr; + if (!drvr) + return; bphy_err(drvr, "Firmware has halted or crashed\n"); brcmf_dev_coredump(dev); - if (drvr->bus_reset.func) - schedule_work(&drvr->bus_reset); + brcmf_bus_schedule_reset(bus_if); } void brcmf_detach(struct device *dev) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c index 9f10b3fff9ff..55f4d7b970f2 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c @@ -2503,6 +2503,7 @@ brcmf_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id) ret = -ENOMEM; goto fail; } + mutex_init(&bus->bus_reset_lock); bus->msgbuf = kzalloc_obj(*bus->msgbuf); if (!bus->msgbuf) { ret = -ENOMEM; @@ -2598,6 +2599,11 @@ brcmf_pcie_remove(struct pci_dev *pdev) if (devinfo->ci) brcmf_pcie_intr_disable(devinfo); + if (devinfo->irq_allocated) + synchronize_irq(pdev->irq); + + brcmf_bus_cancel_reset_work(bus); + brcmf_detach(&pdev->dev); brcmf_free(&pdev->dev); diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c index b725c64e5b5c..9f7ed1d293a0 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c @@ -4560,6 +4560,12 @@ int brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev) return ret; } +void brcmf_sdio_cancel_datawork(struct brcmf_sdio *bus) +{ + if (bus) + cancel_work_sync(&bus->datawork); +} + /* Detach and free everything */ void brcmf_sdio_remove(struct brcmf_sdio *bus) { diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h index 80180d5c6c87..b93d153a8963 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h @@ -361,6 +361,7 @@ int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev); int brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev); void brcmf_sdio_remove(struct brcmf_sdio *bus); void brcmf_sdio_isr(struct brcmf_sdio *bus, bool in_isr); +void brcmf_sdio_cancel_datawork(struct brcmf_sdio *bus); void brcmf_sdio_wd_timer(struct brcmf_sdio *bus, bool active); void brcmf_sdio_wowl_config(struct device *dev, bool enabled); diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c index 0b52f968b907..b41949a9bdc8 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c @@ -1260,6 +1260,7 @@ static int brcmf_usb_probe_cb(struct brcmf_usbdev_info *devinfo, ret = -ENOMEM; goto fail; } + mutex_init(&bus->bus_reset_lock); bus->dev = dev; bus_pub->bus = bus; @@ -1329,6 +1330,8 @@ brcmf_usb_disconnect_cb(struct brcmf_usbdev_info *devinfo) return; brcmf_dbg(USB, "Enter, bus_pub %p\n", devinfo); + brcmf_bus_cancel_reset_work(devinfo->bus_pub.bus); + brcmf_detach(devinfo->dev); brcmf_free(devinfo->dev); kfree(devinfo->bus_pub.bus);