Patch "usb: host: xhci: Fix possible wild pointer when handling abort command" has been added to the 4.9-stable tree

Patch "usb: host: xhci: Fix possible wild pointer when handling abort command" has been added to the 4.9-stable tree

[gregkh]

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

    usb: host: xhci: Fix possible wild pointer when handling abort command

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-host-xhci-fix-possible-wild-pointer-when-handling-abort-command.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 2a7cfdf37b7c08ac29df4c62ea5ccb01474b6597 Mon Sep 17 00:00:00 2001
From: Baolin Wang <baolin.wang@linaro.org>
Date: Tue, 3 Jan 2017 18:28:47 +0200
Subject: usb: host: xhci: Fix possible wild pointer when handling abort command

From: Baolin Wang <baolin.wang@linaro.org>

commit 2a7cfdf37b7c08ac29df4c62ea5ccb01474b6597 upstream.

When current command was supposed to be aborted, host will free the command
in handle_cmd_completion() function. But it might be still referenced by
xhci->current_cmd, which need to set NULL.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/host/xhci-ring.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1368,8 +1368,11 @@ static void handle_cmd_completion(struct
 	 */
 	if (cmd_comp_code == COMP_CMD_ABORT) {
 		xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
-		if (cmd->status == COMP_CMD_ABORT)
+		if (cmd->status == COMP_CMD_ABORT) {
+			if (xhci->current_cmd == cmd)
+				xhci->current_cmd = NULL;
 			goto event_handled;
+		}
 	}
 
 	cmd_type = TRB_FIELD_TO_TYPE(le32_to_cpu(cmd_trb->generic.field[3]));


Patches currently in stable-queue which might be from baolin.wang@linaro.org are

queue-4.9/usb-host-xhci-fix-possible-wild-pointer-when-handling-abort-command.patch
queue-4.9/xhci-handle-command-completion-and-timeout-race.patch