patch "usb: host: xhci: Fix possible wild pointer when handling abort" added to usb-linus

patch "usb: host: xhci: Fix possible wild pointer when handling abort" added to usb-linus

[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

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 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

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.

Cc: <stable@vger.kernel.org>
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(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index acc37311c938..bc8be6f6669e 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1363,8 +1363,11 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
 	 */
 	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]));
-- 
2.11.0