| Message ID | 20210722033439.26550-7-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | UFS patches for kernel v5.15 | expand |
Hi Bart, > @@ -6979,24 +6966,15 @@ static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag) > */ > static int ufshcd_abort(struct scsi_cmnd *cmd) > { > - struct Scsi_Host *host; > - struct ufs_hba *hba; > + struct Scsi_Host *host = cmd->device->host; > + struct ufs_hba *hba = shost_priv(host); > + unsigned int tag = cmd->request->tag; > + struct ufshcd_lrb *lrbp = &hba->lrb[tag]; If tag < 0, lrbp will be assigned incorrect pointer. > unsigned long flags; > - unsigned int tag; > int err = 0; > - struct ufshcd_lrb *lrbp; > u32 reg; > > - host = cmd->device->host; > - hba = shost_priv(host); > - tag = cmd->request->tag; > - lrbp = &hba->lrb[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(); > - } > + WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); > > ufshcd_hold(hba, false); > reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL); Thanks, Daejun
On 7/27/21 11:48 PM, Daejun Park wrote: >> @@ -6979,24 +6966,15 @@ static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag) >> */ >> static int ufshcd_abort(struct scsi_cmnd *cmd) >> { >> - struct Scsi_Host *host; >> - struct ufs_hba *hba; >> + struct Scsi_Host *host = cmd->device->host; >> + struct ufs_hba *hba = shost_priv(host); >> + unsigned int tag = cmd->request->tag; >> + struct ufshcd_lrb *lrbp = &hba->lrb[tag]; > > If tag < 0, lrbp will be assigned incorrect pointer. That shouldn't hurt since lrbp is only used after it has been verified that tag >= 0. Thanks, Bart.
Hi Bart, >On 7/27/21 11:48 PM, Daejun Park wrote: >>> @@ -6979,24 +6966,15 @@ static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag) >>> */ >>> static int ufshcd_abort(struct scsi_cmnd *cmd) >>> { >>> - struct Scsi_Host *host; >>> - struct ufs_hba *hba; >>> + struct Scsi_Host *host = cmd->device->host; >>> + struct ufs_hba *hba = shost_priv(host); >>> + unsigned int tag = cmd->request->tag; >>> + struct ufshcd_lrb *lrbp = &hba->lrb[tag]; >> >> If tag < 0, lrbp will be assigned incorrect pointer. > >That shouldn't hurt since lrbp is only used after it has been verified >that tag >= 0. OK, I got it. Reviewed-by: Daejun Park <daejun7.park@samsung.com> > >Thanks, > >Bart. > > >
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 17afd1b0bd2c..ec12cd4eae03 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -252,11 +252,6 @@ static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable); static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba); static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba); -static inline bool ufshcd_valid_tag(struct ufs_hba *hba, int tag) -{ - return tag >= 0 && tag < hba->nutrs; -} - static inline void ufshcd_enable_irq(struct ufs_hba *hba) { if (!hba->is_irq_enabled) { @@ -2700,20 +2695,12 @@ static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i) */ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) { + struct ufs_hba *hba = shost_priv(host); + int tag = cmd->request->tag; struct ufshcd_lrb *lrbp; - struct ufs_hba *hba; - int tag; int err = 0; - 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(); - } + WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); if (!down_read_trylock(&hba->clk_scaling_lock)) return SCSI_MLQUEUE_HOST_BUSY; @@ -2967,7 +2954,7 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, goto out_unlock; } tag = req->tag; - WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); + WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); /* Set the timeout such that the SCSI error handler is not activated. */ req->timeout = msecs_to_jiffies(2 * timeout); blk_mq_start_request(req); @@ -6677,7 +6664,7 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, goto out_unlock; } tag = req->tag; - WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); + WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); if (unlikely(test_bit(tag, &hba->outstanding_reqs))) { err = -EBUSY; @@ -6979,24 +6966,15 @@ static int ufshcd_try_to_abort_task(struct ufs_hba *hba, int tag) */ static int ufshcd_abort(struct scsi_cmnd *cmd) { - struct Scsi_Host *host; - struct ufs_hba *hba; + struct Scsi_Host *host = cmd->device->host; + struct ufs_hba *hba = shost_priv(host); + unsigned int tag = cmd->request->tag; + struct ufshcd_lrb *lrbp = &hba->lrb[tag]; unsigned long flags; - unsigned int tag; int err = 0; - struct ufshcd_lrb *lrbp; u32 reg; - host = cmd->device->host; - hba = shost_priv(host); - tag = cmd->request->tag; - lrbp = &hba->lrb[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(); - } + WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); ufshcd_hold(hba, false); reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
scsi_add_host() allocates shost->can_queue tags. ufshcd_init() sets shost->can_queue to hba->nutrs. In other words, we know that tag values will less than hba->nutrs. Hence remove the checks that verify that blk_get_request() returns a tag less than hba->nutrs. This check was introduced by commit 14497328b6a6 ("scsi: ufs: verify command tag validity"). Keep the tag >= 0 check because it helps to detect use-after-free issues. Reviewed-by: Bean Huo <beanhuo@micron.com> CC: Avri Altman <avri.altman@wdc.com> Cc: Alim Akhtar <alim.akhtar@samsung.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/ufs/ufshcd.c | 42 ++++++++++----------------------------- 1 file changed, 10 insertions(+), 32 deletions(-)