From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 23 Nov 2009 01:48:34 +0000 (-0500)
Subject: ext4: add check for wraparound in ext4_data_block_valid()
X-Git-Tag: v2.6.33-rc1~330^2~20
X-Git-Url: https://bbs.cooldavid.org/git/?a=commitdiff_plain;h=1585d8d89ae1791d8f957731f5655700fbcc5664;p=net-next-2.6.git

ext4: add check for wraparound in ext4_data_block_valid()

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index dc79b75d8f7..4df8621ec31 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -228,6 +228,7 @@ int ext4_data_block_valid(struct ext4_sb_info *sbi, ext4_fsblk_t start_blk,
 	struct rb_node *n = sbi->system_blks.rb_node;
 
 	if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
+	    (start_blk + count < start_blk) ||
 	    (start_blk + count > ext4_blocks_count(sbi->s_es)))
 		return 0;
 	while (n) {