[PATCH 3.16 151/370] usb: host: xhci: Fix possible wild pointer when handling abort command

Ben Hutchings
2017-03-10T12:46:15Z

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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
@@ -1380,8 +1380,11 @@ 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]));