[PATCH] scsi_dh_alua: Fix a reference counting bug

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Tang Junhui <tang.junhui@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index f375167..7bb2068 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);
 	}
 }
-- 
2.10.1

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux