6.12-stable review patch. If anyone has any objections, please let me know.
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From: Chenyuan Yang chenyuan0y@gmail.com
[ Upstream commit 4c324085062919d4e21c69e5e78456dcec0052fe ]
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.
Signed-off-by: Chenyuan Yang chenyuan0y@gmail.com Link: https://lore.kernel.org/r/20250410001320.2219341-1-chenyuan0y@gmail.com Fixes: f1304d442077 ("scsi: ufs: mcq: Added ufshcd_mcq_abort()") Reviewed-by: Bart Van Assche bvanassche@acm.org Reviewed-by: Peter Wang peter.wang@mediatek.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ufs/core/ufs-mcq.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c index dba935c712d64..45b04f3c37764 100644 --- a/drivers/ufs/core/ufs-mcq.c +++ b/drivers/ufs/core/ufs-mcq.c @@ -673,13 +673,6 @@ int ufshcd_mcq_abort(struct scsi_cmnd *cmd) unsigned long flags; int err;
- if (!ufshcd_cmd_inflight(lrbp->cmd)) { - dev_err(hba->dev, - "%s: skip abort. cmd at tag %d already completed.\n", - __func__, tag); - return FAILED; - } - /* Skip task abort in case previous aborts failed and report failure */ if (lrbp->req_abort_skip) { dev_err(hba->dev, "%s: skip abort. tag %d failed earlier\n", @@ -688,6 +681,11 @@ int ufshcd_mcq_abort(struct scsi_cmnd *cmd) }
hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd)); + if (!hwq) { + dev_err(hba->dev, "%s: skip abort. cmd at tag %d already completed.\n", + __func__, tag); + return FAILED; + }
if (ufshcd_mcq_sqe_search(hba, hwq, tag)) { /*