[patch] udf: possible null pointer dereference while load_partition

[Dmitriy Monakhov]

sb_read may return NULL, let's explicitly check it.
Signed-off-by: Dmitriy Monakhov <[EMAIL PROTECTED]>


diff --git a/fs/udf/super.c b/fs/udf/super.c
index f4b3265..951b85d 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1407,6 +1407,8 @@ 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));