Commit 2f974865 authored by Eryu Guan's avatar Eryu Guan Committed by Theodore Ts'o

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: default avatarEryu Guan <guaneryu@gmail.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent 9d506594
...@@ -377,7 +377,7 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) ...@@ -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 lblock = le32_to_cpu(ext->ee_block);
ext4_lblk_t last = lblock + len - 1; ext4_lblk_t last = lblock + len - 1;
if (lblock > last) if (len == 0 || lblock > last)
return 0; return 0;
return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
} }
......
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