From: Jiri Slaby Date: Wed, 23 Sep 2009 14:15:35 +0000 (+0200) Subject: SCSI: scsi_lib: fix potential NULL dereference X-Git-Tag: v2.6.32.50~9 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=a488d32120a22ca2a2f436ab91947bcb352ee7cf;p=linux-pvops.git SCSI: scsi_lib: fix potential NULL dereference commit 03b147083a2f9a2a3fbbd2505fa88ffa3c6ab194 upstream. Stanse found a potential NULL dereference in scsi_kill_request. Instead of triggering BUG() in 'if (unlikely(cmd == NULL))' branch, the kernel will Oops earlier on cmd dereference. Move the dereferences after the if. Signed-off-by: Jiri Slaby Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 1ae7b7c848b9..00e3961da07e 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1370,9 +1370,9 @@ static int scsi_lld_busy(struct request_queue *q) static void scsi_kill_request(struct request *req, struct request_queue *q) { struct scsi_cmnd *cmd = req->special; - struct scsi_device *sdev = cmd->device; - struct scsi_target *starget = scsi_target(sdev); - struct Scsi_Host *shost = sdev->host; + struct scsi_device *sdev; + struct scsi_target *starget; + struct Scsi_Host *shost; blk_start_request(req); @@ -1382,6 +1382,9 @@ static void scsi_kill_request(struct request *req, struct request_queue *q) BUG(); } + sdev = cmd->device; + starget = scsi_target(sdev); + shost = sdev->host; scsi_init_cmd_errh(cmd); cmd->result = DID_NO_CONNECT << 16; atomic_inc(&cmd->device->iorequest_cnt);