Linux SCSI subsystem development
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From: Bart Van Assche <bvanassche@acm.org>
To: Chenyuan Yang <chenyuan0y@gmail.com>,
	alim.akhtar@samsung.com, avri.altman@wdc.com,
	James.Bottomley@HansenPartnership.com,
	martin.petersen@oracle.com, peter.wang@mediatek.com,
	minwoo.im@samsung.com, manivannan.sadhasivam@linaro.org,
	viro@zeniv.linux.org.uk, cw9316.lee@samsung.com,
	quic_nguyenb@quicinc.com, quic_cang@quicinc.com,
	stanley.chu@mediatek.com
Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] scsi: ufs: mcq: Add NULL check in ufshcd_mcq_abort()
Date: Thu, 10 Apr 2025 13:46:21 -0700	[thread overview]
Message-ID: <5c4b5e2e-eac1-4be5-bf72-2c151979a5cf@acm.org> (raw)
In-Reply-To: <20250410001320.2219341-1-chenyuan0y@gmail.com>

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@acm.org>

  reply	other threads:[~2025-04-10 20:46 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-10  0:13 [PATCH v2] scsi: ufs: mcq: Add NULL check in ufshcd_mcq_abort() Chenyuan Yang
2025-04-10 20:46 ` Bart Van Assche [this message]
2025-04-11  2:41 ` Peter Wang (王信友)
2025-04-12 10:28 ` Martin K. Petersen

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