[lkml]   [2012]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[34-longterm 169/196] fix oops in scsi_run_queue()
From: James Bottomley <>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit c055f5b2614b4f758ae6cc86733f31fa4c2c5844 upstream.

The recent commit closing the race window in device teardown:

commit 86cbfb5607d4b81b1a993ff689bbd2addd5d3a9b
Author: James Bottomley <>
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 <>
Signed-off-by: James Bottomley <>
Signed-off-by: Paul Gortmaker <>
drivers/scsi/scsi_lib.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c2a9e12..725f3cd 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -400,10 +400,15 @@ static inline int scsi_host_is_busy(struct Scsi_Host *shost)
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;
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)


 \ /
  Last update: 2012-03-13 01:35    [W:0.520 / U:0.912 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site