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-Url: http://git.osdn.net/view?a=commitdiff_plain;h=86bb666386ee632879c278d9e95378aed5f99ed9;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git

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

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>
---

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 5f2951dd4d79..1ea3741bbe1a 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1365,8 +1365,11 @@ 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]));