summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/scsi_debug.c
diff options
context:
space:
mode:
authorDouglas Gilbert <dgilbert@interlog.com>2020-07-02 10:53:55 -0400
committerMartin K. Petersen <martin.petersen@oracle.com>2020-07-02 23:49:54 -0400
commit74595c044cb56cb073370c09fefc23eb8ed6d835 (patch)
tree093a812cdbb969fed4f9aa8f2753fcb0af2394a4 /drivers/scsi/scsi_debug.c
parent93bf02e5a2c2418bc290a778cd537837d789d9ee (diff)
downloadlinux-74595c044cb56cb073370c09fefc23eb8ed6d835.tar.gz
linux-74595c044cb56cb073370c09fefc23eb8ed6d835.tar.bz2
linux-74595c044cb56cb073370c09fefc23eb8ed6d835.zip
scsi: scsi_debug: Fix in_use bitmap corruption
Heavy testing indicates the irqsave() spinlock around the __set_bit() is insufficient to stop following clear_bit() calls being rarely applied out-of-order. Also the nearby failed kzalloc() path leading to SCSI_MLQUEUE_HOST_BUSY does not properly undo the in_use bitmap and num_in_q, fix. Link: https://lore.kernel.org/r/20200702145355.522283-1-dgilbert@interlog.com Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/scsi_debug.c')
-rw-r--r--drivers/scsi/scsi_debug.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 843cccb38cb7..4692f5b6ad13 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -5430,7 +5430,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
else
return SCSI_MLQUEUE_HOST_BUSY;
}
- __set_bit(k, sqp->in_use_bm);
+ set_bit(k, sqp->in_use_bm);
atomic_inc(&devip->num_in_q);
sqcp = &sqp->qc_arr[k];
sqcp->a_cmnd = cmnd;
@@ -5439,10 +5439,13 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
spin_unlock_irqrestore(&sqp->qc_lock, iflags);
if (unlikely(sdebug_every_nth && sdebug_any_injecting_opt))
setup_inject(sqp, sqcp);
- if (sd_dp == NULL) {
+ if (!sd_dp) {
sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC);
- if (sd_dp == NULL)
+ if (!sd_dp) {
+ atomic_dec(&devip->num_in_q);
+ clear_bit(k, sqp->in_use_bm);
return SCSI_MLQUEUE_HOST_BUSY;
+ }
new_sd_dp = true;
} else {
new_sd_dp = false;