[25/27] [SCSI] sym53c8xx: Fix NULL pointer dereference in slave_destroy

Greg KH
2012-01-23T23:46:27Z

From: Stratos Psomadakis <psomas@gentoo.org>

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>

---
drivers/scsi/sym53c8xx_2/sym_glue.c | 4 ++++
1 file changed, 4 insertions(+)

--- 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(stru
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) {