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authorEryu Guan <guaneryu@gmail.com>2015-05-14 19:00:45 -0400
committerSasha Levin <sasha.levin@oracle.com>2015-06-10 13:42:24 -0400
commitc164d09cd8eb3f6b8c183409695dc0eb3c4c503a (patch)
treeb6a9a6ed4d7b4bacc4b1fbc3ba5c392345b9d91b
parentd08570f3f052876a7a4472b66daac86c6a11b6b0 (diff)
ext4: check for zero length extent explicitly
[ Upstream commit 2f974865ffdfe7b9f46a9940836c8b167342563d ] 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 Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--fs/ext4/extents.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 6cfacbb0f928..b5fcb1ac0dd7 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -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);
}