From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Ding <dinggnu-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: [PATCH] i2c: busses/i2c-pxa.c: fix potential null pointer dereference error
Date: Mon,  4 Feb 2013 23:11:36 +0100
Message-ID: <1360015899-13706-1-git-send-email-dinggnu@gmail.com>
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Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>, Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>, Haojian Zhuang <haojian.zhuang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Cong Ding <dinggnu-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
List-Id: linux-i2c@vger.kernel.org

If it goes to eclk through line 1107, the variable res would be NULL. It will
cause a null pointer dereference error if we call release_mem_region.

Signed-off-by: Cong Ding <dinggnu-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/i2c/busses/i2c-pxa.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 1034d93..eadf1a4 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -1211,7 +1211,8 @@ eremap:
 eclk:
 	kfree(i2c);
 emalloc:
-	release_mem_region(res->start, resource_size(res));
+	if (!res)
+		release_mem_region(res->start, resource_size(res));
 	return ret;
 }
 
-- 
1.7.9.5