From a4dbc2902ff426f9ded7542eeb3f347442f7fc1f Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Sun, 1 May 2011 09:42:07 -0500 Subject: fix oops in scsi_run_queue() 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: Greg Kroah-Hartman --- 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 fb2bb35c62c..415fdf2bd94 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; 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); -- cgit v1.2.3