path: root/fs
diff options
authorEryu Guan <guaneryu@gmail.com>2015-05-14 19:00:45 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-06-06 08:19:36 -0700
commitfc371c057452f734868ad2b2738cc715fad74d87 (patch)
treec3a1f56c15784c87a6b873e6de057bb990051066 /fs
parent1e217f7207a18add4440166fa818d65b53f5422a (diff)
ext4: check for zero length extent explicitly
commit 2f974865ffdfe7b9f46a9940836c8b167342563d upstream. The following commit introduced a bug when checking for zero length extent 5946d08 ext4: check for overlapping extents in ext4_valid_extent_entries() Zero length extent could pass the check if lblock is zero. Adding the explicit check for zero length back. Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 96a1ce159f51..4e237a6b4b33 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -361,7 +361,7 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
ext4_lblk_t last = lblock + len - 1;
- if (lblock > last)
+ if (len == 0 || lblock > last)
return 0;
return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);