| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 39/64] ext4: check for zero length extent explicitly | Date | Wed, 3 Jun 2015 20:43:07 +0900 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Eryu Guan <guaneryu@gmail.com>
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>
--- fs/ext4/extents.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -361,7 +361,7 @@ static int ext4_valid_extent(struct inod 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); }
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