A race condition appear to exist between request completion when
scsi_done() is called to end the request and set the tag back to
-1 (at blk_queue_end_tag() scsi_end_request), and scsi layer error
handling which aborts the command and reuses it to request sense
data. Sending the request sense is done with tag which was set to -1
and so it is invalid.
Assert command tag passed from scsi layer is valid.

Reviewed-by: Subhash Jadavani <subha...@codeaurora.org>
Reviewed-by: Dolev Raviv <dra...@codeaurora.org>
Signed-off-by: Gilad Broner <gbro...@codeaurora.org>
Signed-off-by: Yaniv Gardi <yga...@codeaurora.org>

---
 drivers/scsi/ufs/ufshcd.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 7ae87c9..8a34f61 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -190,6 +190,10 @@ static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
                struct ufs_pa_layer_attr *desired_pwr_mode);
 static int ufshcd_change_power_mode(struct ufs_hba *hba,
                             struct ufs_pa_layer_attr *pwr_mode);
+static inline bool ufshcd_valid_tag(struct ufs_hba *hba, int tag)
+{
+       return tag >= 0 && tag < hba->nutrs;
+}
 
 static inline int ufshcd_enable_irq(struct ufs_hba *hba)
 {
@@ -1309,6 +1313,12 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, 
struct scsi_cmnd *cmd)
        hba = shost_priv(host);
 
        tag = cmd->request->tag;
+       if (!ufshcd_valid_tag(hba, tag)) {
+               dev_err(hba->dev,
+                       "%s: invalid command tag %d: cmd=0x%p, 
cmd->request=0x%p",
+                       __func__, tag, cmd, cmd->request);
+               BUG();
+       }
 
        spin_lock_irqsave(hba->host->host_lock, flags);
        switch (hba->ufshcd_state) {
@@ -3861,13 +3871,23 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
        host = cmd->device->host;
        hba = shost_priv(host);
        tag = cmd->request->tag;
+       if (!ufshcd_valid_tag(hba, tag)) {
+               dev_err(hba->dev,
+                       "%s: invalid command tag %d: cmd=0x%p, 
cmd->request=0x%p",
+                       __func__, tag, cmd, cmd->request);
+               BUG();
+       }
 
        ufshcd_hold(hba, false);
+       reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
        /* If command is already aborted/completed, return SUCCESS */
-       if (!(test_bit(tag, &hba->outstanding_reqs)))
+       if (!(test_bit(tag, &hba->outstanding_reqs))) {
+               dev_err(hba->dev,
+                       "%s: cmd at tag %d already completed, 
outstanding=0x%lx, doorbell=0x%x\n",
+                       __func__, tag, hba->outstanding_reqs, reg);
                goto out;
+       }
 
-       reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
        if (!(reg & (1 << tag))) {
                dev_err(hba->dev,
                "%s: cmd was completed, but without a notifying intr, tag = %d",
-- 
1.8.5.2

-- 
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to