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| author | Eryu Guan <guaneryu@gmail.com> | 2015-05-14 19:00:45 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-06 08:19:36 -0700 |
| commit | fc371c057452f734868ad2b2738cc715fad74d87 (patch) | |
| tree | c3a1f56c15784c87a6b873e6de057bb990051066 | |
| parent | 1e217f7207a18add4440166fa818d65b53f5422a (diff) | |
| download | lwn-fc371c057452f734868ad2b2738cc715fad74d87.tar.gz lwn-fc371c057452f734868ad2b2738cc715fad74d87.zip | |
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>
| -rw-r--r-- | fs/ext4/extents.c | 2 |
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); } |