[1/2] usb: host: xhci: Fix possible wild pointer when handling abort command

Message ID b0157454dce55d1288c7e097ddffc3d6c81351b2.1480922249.git.baolin.wang@linaro.org
State Accepted
Commit 2a7cfdf37b7c08ac29df4c62ea5ccb01474b6597
Headers show

Commit Message

(Exiting) Baolin Wang Dec. 5, 2016, 7:51 a.m.
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>

---
This patch is based on Lu Baolu's new fix patch:
usb: xhci: fix possible wild pointer
https://www.spinics.net/lists/linux-usb/msg150219.html
---
 drivers/usb/host/xhci-ring.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

-- 
1.7.9.5

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Patch

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 62dd1c7..9965a4c 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1362,8 +1362,11 @@  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]));