4.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eryu Guan <guane...@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 <guane...@gmail.com>
Signed-off-by: Theodore Ts'o <ty...@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/ext4/extents.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -377,7 +377,7 @@ 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);
 }


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to