[SCSI] fix oops in scsi_run_queue()
The recent commit closing the race window in device teardown:
commit 86cbfb5607d4b81b1a993ff689bbd2addd5d3a9b
Author: James Bottomley <James.Bottomley@suse.de>
Date: Fri Apr 22 10:39:59 2011 -0500
[SCSI] put stricter guards on queue dead checks
is causing a potential NULL deref in scsi_run_queue() because the
q->queuedata may already be NULL by the time this function is called.
Since we shouldn't be running a queue that is being torn down, simply
add a NULL check in scsi_run_queue() to forestall this.
Tested-by: Jim Schutt <jaschut@sandia.gov>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e9901b8..0bac91e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -400,10 +400,15 @@
static void scsi_run_queue(struct request_queue *q)
{
struct scsi_device *sdev = q->queuedata;
- struct Scsi_Host *shost = sdev->host;
+ struct Scsi_Host *shost;
LIST_HEAD(starved_list);
unsigned long flags;
+ /* if the device is dead, sdev will be NULL, so no queue to run */
+ if (!sdev)
+ return;
+
+ shost = sdev->host;
if (scsi_target(sdev)->single_lun)
scsi_single_lun_run(sdev);