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 5f2951d..1ea3741 100644 (file)
--- 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]));