From 02bd3499a3be984f1e88821c3ed252c8c49c498e Mon Sep 17 00:00:00 2001
From: James Bottomley <James.Bottomley@HansenPartnership.com>
Date: Fri, 12 Dec 2008 13:28:29 -0600
Subject: [SCSI] scsi_lib: only call scsi_unprep_request() under queue lock

It's called under that lock everywhere else and it does alter the
request state, so it should be.

This one occurance in scsi_requeue_command() could open a window where
req->special is set to NULL while the requests is going through either
timeout or completion processing leading to NULL pointer derefs of the
sort complained of in bugzillas 12020 and 12195.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
---
 drivers/scsi/scsi_lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/scsi/scsi_lib.c')

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index fa45a1a6686..148d3af92ae 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -648,8 +648,8 @@ static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
 	struct request *req = cmd->request;
 	unsigned long flags;
 
-	scsi_unprep_request(req);
 	spin_lock_irqsave(q->queue_lock, flags);
+	scsi_unprep_request(req);
 	blk_requeue_request(q, req);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 
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