ext4: check for zero length extent explicitly

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>
Cc: stable@vger.kernel.org
This commit is contained in:
Eryu Guan 2015-05-14 19:00:45 -04:00 committed by Theodore Ts'o
parent 9d50659406
commit 2f974865ff
1 changed files with 1 additions and 1 deletions

View File

@ -377,7 +377,7 @@ 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);
}