From 04c116e2bdfc3969f9819d2cebfdf678353c354c Mon Sep 17 00:00:00 2001 From: Can Guo Date: Mon, 18 Dec 2023 07:32:17 -0800 Subject: [PATCH] scsi: ufs: core: Let the sq_lock protect sq_tail_slot access When accessing sq_tail_slot without protection from sq_lock, a race condition can cause multiple SQEs to be copied to duplicate SQE slots. This can lead to multiple stability issues. Fix this by moving the *dest initialization in ufshcd_send_command() back under protection from the sq_lock. Fixes: 3c85f087faec ("scsi: ufs: mcq: Use pointer arithmetic in ufshcd_send_command()") Signed-off-by: Can Guo Link: https://lore.kernel.org/r/1702913550-20631-1-git-send-email-quic_cang@quicinc.com Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen --- drivers/ufs/core/ufshcd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index bce0d2a9a7f3a..16d76325039a5 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -2274,9 +2274,10 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag, if (is_mcq_enabled(hba)) { int utrd_size = sizeof(struct utp_transfer_req_desc); struct utp_transfer_req_desc *src = lrbp->utr_descriptor_ptr; - struct utp_transfer_req_desc *dest = hwq->sqe_base_addr + hwq->sq_tail_slot; + struct utp_transfer_req_desc *dest; spin_lock(&hwq->sq_lock); + dest = hwq->sqe_base_addr + hwq->sq_tail_slot; memcpy(dest, src, utrd_size); ufshcd_inc_sq_tail(hwq); spin_unlock(&hwq->sq_lock); -- 2.30.2