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

[Mathias Nyman]

On 05.12.2016 09:51, Baolin Wang wrote:
> 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@xxxxxxxxxx>
> ---
> 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(-)
>
> 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]));

True, thanks

-Mathias