From 951744fea0aea9adbd7c8cacb3605f2d69a66f96 Mon Sep 17 00:00:00 2001
From: Dmitriy Monakhov <dmonakhov@openvz.org>
Date: Tue, 8 May 2007 00:35:22 -0700
Subject: [PATCH] udf: possible null pointer dereference while load_partition

sb_read may return NULL, let's explicitly check it.

Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/udf/super.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index a92daaba6c4c..9b8644a06e53 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1403,6 +1403,8 @@ udf_load_partition(struct super_block *sb, kernel_lb_addr *fileset)
 
 					pos = udf_block_map(UDF_SB_VAT(sb), 0);
 					bh = sb_bread(sb, pos);
+					if (!bh)
+						return 1;
 					UDF_SB_TYPEVIRT(sb,i).s_start_offset =
 						le16_to_cpu(((struct virtualAllocationTable20 *)bh->b_data + udf_ext0_offset(UDF_SB_VAT(sb)))->lengthHeader) +
 							udf_ext0_offset(UDF_SB_VAT(sb));