[PATCH v2 2/3] nvme-tcp: fix possible use-after-free in transport error_recovery work

[Hannes Reinecke]

On 2/1/22 13:54, Sagi Grimberg wrote:
> While nvme_tcp_submit_async_event_work is checking the ctrl and queue
> state before preparing the AER command and scheduling io_work, in order
> to fully prevent a race where this check is not reliable the error
> recovery work must flush async_event_work before continuing to destroy
> the admin queue after setting the ctrl state to RESETTING such that
> there is no race .submit_async_event and the error recovery handler
> itself changing the ctrl state.
> 
> Tested-by: Chris Leech <cleech at redhat.com>
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
> ---
>   drivers/nvme/host/tcp.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 4ceb28675fdf..01e24b5703db 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -2096,6 +2096,7 @@ static void nvme_tcp_error_recovery_work(struct work_struct *work)
>   	struct nvme_ctrl *ctrl = &tcp_ctrl->ctrl;
>   
>   	nvme_stop_keep_alive(ctrl);
> +	flush_work(&ctrl->async_event_work);
>   	nvme_tcp_teardown_io_queues(ctrl, false);
>   	/* unquiesce to fail fast pending requests */
>   	nvme_start_queues(ctrl);

Reviewed-by: Hannes Reinecke <hare at suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare at suse.de			                  +49 911 74053 688
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