From: Baolin Wang <baolin.wang@linaro.org>
Date: Tue, 3 Jan 2017 16:28:47 +0000 (+0200)
Subject: usb: host: xhci: Fix possible wild pointer when handling abort command
X-Git-Tag: v4.10-rc3~1^2~16
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=2a7cfdf37b7c08ac29df4c62ea5ccb01474b6597;p=linux.git

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>
---

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]));