From: Stratos Psomadakis <psomas@gentoo.org>
Date: Sun, 4 Dec 2011 00:23:54 +0000 (+0200)
Subject: sym53c8xx: Fix NULL pointer dereference in slave_destroy
X-Git-Tag: v2.6.32.55~3
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=751153cccad7b285060c11af30379fcf599dc625;p=linux-pvops.git

sym53c8xx: Fix NULL pointer dereference in slave_destroy

commit cced5041ed5a2d1352186510944b0ddfbdbe4c0b upstream.

sym53c8xx_slave_destroy unconditionally assumes that sym53c8xx_slave_alloc has
succesesfully allocated a sym_lcb. This can lead to a NULL pointer dereference
(exposed by commit 4e6c82b).

Signed-off-by: Stratos Psomadakis <psomas@gentoo.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c
index 45374d66d26a..c19ca5e35baa 100644
--- a/drivers/scsi/sym53c8xx_2/sym_glue.c
+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c
@@ -837,6 +837,10 @@ static void sym53c8xx_slave_destroy(struct scsi_device *sdev)
 	struct sym_lcb *lp = sym_lp(tp, sdev->lun);
 	unsigned long flags;
 
+	/* if slave_alloc returned before allocating a sym_lcb, return */
+	if (!lp)
+		return;
+
 	spin_lock_irqsave(np->s.host->host_lock, flags);
 
 	if (lp->busy_itlq || lp->busy_itl) {