diff options
| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2016-11-01 08:19:57 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-18 10:51:48 +0100 |
| commit | 2850fad5acb02d58e45bf7cab169418aab8c51f4 (patch) | |
| tree | 5458cfeaf8f3ef7556fd60696c081b476aaf6111 | |
| parent | 5fac70d772a4d360eb3453f76f860c68eb192f1d (diff) | |
scsi: scsi_dh_alua: Fix a reference counting bug
commit df3d422cbac685da882e4c239dfda07de33d431b upstream.
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>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 6e825036be89..920c42151e92 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -890,6 +890,7 @@ 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; } } @@ -901,7 +902,8 @@ 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); } } |