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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2016-11-01 17:19:57 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2016-11-01 20:32:24 +0300 |
| commit | df3d422cbac685da882e4c239dfda07de33d431b (patch) | |
| tree | 5d61ed8c7e551eb980a4c1772964bdce25d8c1d8 | |
| parent | aac173e9618faadf8f92af6cc05e64f7acc64d79 (diff) | |
| download | linux-df3d422cbac685da882e4c239dfda07de33d431b.tar.xz | |
scsi: scsi_dh_alua: Fix a reference counting bug
The code at the end of alua_rtpg_work() is as follows:
scsi_device_put(sdev);
kref_put(&pg->kref, release_port_group);
In other words, alua_rtpg_queue() must hold an sdev reference and a pg
reference before queueing rtpg work. If no rtpg work is queued no
additional references should be held when alua_rtpg_queue() returns. If
no rtpg work is queued, ensure that alua_rtpg_queue() only gives up the
sdev reference if that reference was obtained by the same
alua_rtpg_queue() call.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reported-by: Tang Junhui <tang.junhui@zte.com.cn>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Tang Junhui <tang.junhui@zte.com.cn>
Cc: <stable@vger.kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
| -rw-r--r-- | drivers/scsi/device_handler/scsi_dh_alua.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index f375167f16ea..7bb20684e9fa 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -891,6 +891,7 @@ static void alua_rtpg_queue(struct alua_port_group *pg, /* Do not queue if the worker is already running */ if (!(pg->flags & ALUA_PG_RUNNING)) { kref_get(&pg->kref); + sdev = NULL; start_queue = 1; } } @@ -902,7 +903,8 @@ static void alua_rtpg_queue(struct alua_port_group *pg, if (start_queue && !queue_delayed_work(alua_wq, &pg->rtpg_work, msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) { - scsi_device_put(sdev); + if (sdev) + scsi_device_put(sdev); kref_put(&pg->kref, release_port_group); } } |