Re: [PATCH v2] scsi: ufs: mcq: Add NULL check in ufshcd_mcq_abort()

[Bart Van Assche]

On 4/9/25 5:13 PM, Chenyuan Yang wrote:
> A race can occur between the MCQ completion path and the abort handler:
> once a request completes, __blk_mq_free_request() sets rq->mq_hctx to
> NULL, meaning the subsequent ufshcd_mcq_req_to_hwq() call in
> ufshcd_mcq_abort() can return a NULL pointer. If this NULL pointer is
> dereferenced, the kernel will crash.
>
> Add a NULL check for the returned hwq pointer. If hwq is NULL, log an
> error and return FAILED, preventing a potential NULL-pointer dereference.
> As suggested by Bart, the ufshcd_cmd_inflight() check is removed.
>
> This is similar to the fix in commit 74736103fb41
> ("scsi: ufs: core: Fix ufshcd_abort_one racing issue").
>
> This is found by our static analysis tool KNighter.
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>