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authorYaniv Gardi <ygardi@codeaurora.org>2016-02-01 15:02:39 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2016-02-23 21:27:02 -0500
commit14497328b6a628cedafdd2df1bb8d3e9d1d5338f (patch)
tree197639caef71a4938c4360ce0df68d5566419334 /drivers/scsi/ufs
parentscsi: ufs: clear fields UTRD, UPIU req and rsp before new transfers (diff)
downloadlinux-dev-14497328b6a628cedafdd2df1bb8d3e9d1d5338f.tar.xz
linux-dev-14497328b6a628cedafdd2df1bb8d3e9d1d5338f.zip
scsi: ufs: verify command tag validity
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 <subhashj@codeaurora.org> Reviewed-by: Dolev Raviv <draviv@codeaurora.org> Signed-off-by: Gilad Broner <gbroner@codeaurora.org> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/ufs')
-rw-r--r--drivers/scsi/ufs/ufshcd.c24
1 files changed, 22 insertions, 2 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 7ae87c9c3496..8a34f61be679 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",