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patch "xhci: Fix memory leak when caching protocol extended capability PSI" added to usb-linus

PATCH [email protected] 1 participant 1 message Feb 10, 2020

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This is a note to let you know that I've just added the patch titled

xhci: Fix memory leak when caching protocol extended capability PSI

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From fc57313d1017dd6b6f37a94e88daa8df54368ecc Mon Sep 17 00:00:00 2001
From: Mathias Nyman <[email protected]>
Date: Mon, 10 Feb 2020 15:45:51 +0200
Subject: xhci: Fix memory leak when caching protocol extended capability PSI
tables

xhci driver assumed that xHC controllers have at most one custom supported speed table (PSI) for all usb 3.x ports.
Memory was allocated for one PSI table under the xhci hub structure.

Turns out this is not the case, some controllers have a separate "supported protocol capability" entry with a PSI table for each port. This means each usb3 roothub port can in theory support different custom speeds.

To solve this, cache all supported protocol capabilities with their PSI tables in an array, and add pointers to the xhci port structure so that every port points to its capability entry in the array.

When creating the SuperSpeedPlus USB Device Capability BOS descriptor for the xhci USB 3.1 roothub we for now will use only data from the first USB 3.1 capable protocol capability entry in the array. This could be improved later, this patch focuses resolving the memory leak.

Fixes 47189098f8be ("xhci: parse xhci protocol speed ID list for usb 3.1 usage")
Cc stable <[email protected]> # v4.4+
---
 drivers/usb/host/xhci-hub.c | 25 +++++++++++-----
 drivers/usb/host/xhci-mem.c | 58 +++++++++++++++++++++++--------------
 drivers/usb/host/xhci.h     | 14 +++++++--
 3 files changed, 64 insertions(+), 33 deletions(-)
drivers/usb/host/xhci-hub.c +17 -8
index 7a3a29e5e9d2..af92b2576fe9 100644
@@ -55,6 +55,7 @@ static u8 usb_bos_descriptor [] = {
 static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 				     u16 wLength)
 {
+	struct xhci_port_cap *port_cap = NULL;
 	int i, ssa_count;
 	u32 temp;
 	u16 desc_size, ssp_cap_size, ssa_size = 0;
@@ -64,16 +65,24 @@ static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 	ssp_cap_size = sizeof(usb_bos_descriptor) - desc_size;
 
 	/* does xhci support USB 3.1 Enhanced SuperSpeed */
-	if (xhci->usb3_rhub.min_rev >= 0x01) {
+	for (i = 0; i < xhci->num_port_caps; i++) {
+		if (xhci->port_caps[i].maj_rev == 0x03 &&
+		    xhci->port_caps[i].min_rev >= 0x01) {
+			usb3_1 = true;
+			port_cap = &xhci->port_caps[i];
+			break;
+		}
+	}
+
+	if (usb3_1) {
 		/* does xhci provide a PSI table for SSA speed attributes? */
-		if (xhci->usb3_rhub.psi_count) {
+		if (port_cap->psi_count) {
 			/* two SSA entries for each unique PSI ID, RX and TX */
-			ssa_count = xhci->usb3_rhub.psi_uid_count * 2;
+			ssa_count = port_cap->psi_uid_count * 2;
 			ssa_size = ssa_count * sizeof(u32);
 			ssp_cap_size -= 16; /* skip copying the default SSA */
 		}
 		desc_size += ssp_cap_size;
-		usb3_1 = true;
 	}
 	memcpy(buf, &usb_bos_descriptor, min(desc_size, wLength));
 
@@ -99,7 +108,7 @@ static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 	}
 
 	/* If PSI table exists, add the custom speed attributes from it */
-	if (usb3_1 && xhci->usb3_rhub.psi_count) {
+	if (usb3_1 && port_cap->psi_count) {
 		u32 ssp_cap_base, bm_attrib, psi, psi_mant, psi_exp;
 		int offset;
 
@@ -111,7 +120,7 @@ static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 
 		/* attribute count SSAC bits 4:0 and ID count SSIC bits 8:5 */
 		bm_attrib = (ssa_count - 1) & 0x1f;
-		bm_attrib |= (xhci->usb3_rhub.psi_uid_count - 1) << 5;
+		bm_attrib |= (port_cap->psi_uid_count - 1) << 5;
 		put_unaligned_le32(bm_attrib, &buf[ssp_cap_base + 4]);
 
 		if (wLength < desc_size + ssa_size)
@@ -124,8 +133,8 @@ static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
 		 * USB 3.1 requires two SSA entries (RX and TX) for every link
 		 */
 		offset = desc_size;
-		for (i = 0; i < xhci->usb3_rhub.psi_count; i++) {
-			psi = xhci->usb3_rhub.psi[i];
+		for (i = 0; i < port_cap->psi_count; i++) {
+			psi = port_cap->psi[i];
 			psi &= ~USB_SSP_SUBLINK_SPEED_RSVD;
 			psi_exp = XHCI_EXT_PORT_PSIE(psi);
 			psi_mant = XHCI_EXT_PORT_PSIM(psi);
drivers/usb/host/xhci-mem.c +36 -22

102 lines not on this page · raw message

drivers/usb/host/xhci.h +11 -3
index 13d8838cd552..3ecee10fdcdc 100644
@@ -1702,12 +1702,20 @@ struct xhci_bus_state {
  * Intel Lynx Point LP xHCI host.
  */
 #define	XHCI_MAX_REXIT_TIMEOUT_MS	20
+struct xhci_port_cap {
+	u32			*psi;	/* array of protocol speed ID entries */
+	u8			psi_count;
+	u8			psi_uid_count;
+	u8			maj_rev;
+	u8			min_rev;
+};
 
 struct xhci_port {
 	__le32 __iomem		*addr;
 	int			hw_portnum;
 	int			hcd_portnum;
 	struct xhci_hub		*rhub;
+	struct xhci_port_cap	*port_cap;
 };
 
 struct xhci_hub {
@@ -1719,9 +1727,6 @@ struct xhci_hub {
 	/* supported prococol extended capabiliy values */
 	u8			maj_rev;
 	u8			min_rev;
-	u32			*psi;	/* array of protocol speed ID entries */
-	u8			psi_count;
-	u8			psi_uid_count;
 };
 
 /* There is one xhci_hcd structure per controller */
@@ -1880,6 +1885,9 @@ struct xhci_hcd {
 	/* cached usb2 extened protocol capabilites */
 	u32                     *ext_caps;
 	unsigned int            num_ext_caps;
+	/* cached extended protocol port capabilities */
+	struct xhci_port_cap	*port_caps;
+	unsigned int		num_port_caps;
 	/* Compliance Mode Recovery Data */
 	struct timer_list	comp_mode_recovery_timer;
 	u32			port_status_u0;
Signature · 1 line
2.25.0