scsi: ufs: core: Fix racing issue between ufshcd_mcq_abort() and ISR

commit 27900d7119c464b43cd9eac69c85884d17bae240 upstream.

If command timeout happens and cq complete IRQ is raised at the same time,
ufshcd_mcq_abort clears lprb->cmd and a NULL pointer deref happens in the
ISR. Error log:

ufshcd_abort: Device abort task at tag 18
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000108
pc : [0xffffffe27ef867ac] scsi_dma_unmap+0xc/0x44
lr : [0xffffffe27f1b898c] ufshcd_release_scsi_cmd+0x24/0x114

Fixes: f1304d442077 ("scsi: ufs: mcq: Added ufshcd_mcq_abort()")
Cc: stable@vger.kernel.org
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Link: https://lore.kernel.org/r/20231106075117.8995-1-peter.wang@mediatek.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 5c75ab9..0787456 100644 (file)
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -630,6 +630,7 @@ int ufshcd_mcq_abort(struct scsi_cmnd *cmd)
        int tag = scsi_cmd_to_rq(cmd)->tag;
        struct ufshcd_lrb *lrbp = &hba->lrb[tag];
        struct ufs_hw_queue *hwq;
+       unsigned long flags;
        int err = FAILED;
 
        if (!ufshcd_cmd_inflight(lrbp->cmd)) {
@@ -670,8 +671,10 @@ int ufshcd_mcq_abort(struct scsi_cmnd *cmd)
        }
 
        err = SUCCESS;
+       spin_lock_irqsave(&hwq->cq_lock, flags);
        if (ufshcd_cmd_inflight(lrbp->cmd))
                ufshcd_release_scsi_cmd(hba, lrbp);
+       spin_unlock_irqrestore(&hwq->cq_lock, flags);
 
 out:
        return err;