Commit 2f974865 authored May 14, 2015 by Eryu Guan Committed by Theodore Ts'o May 14, 2015

ext4: check for zero length extent explicitly



The following commit introduced a bug when checking for zero length extent

5946d089 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

parent 9d506594

fs/ext4/extents.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);
		}