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authorEryu Guan <guaneryu@gmail.com>2015-05-14 19:00:45 -0400
committerZefan Li <lizefan@huawei.com>2015-09-18 09:20:40 +0800
commitfc83d2a48ec24c7836bcef1e67af16a84dc3f570 (patch)
tree7e9bcba5e03ae6e82b7cfcfdd794b9a8676eb689
parente92c54259e8d8bae9a3e1a4ce840ff0246cb8b3f (diff)
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: Zefan Li <lizefan@huawei.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 bb72833e9455..bbe09a975003 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -320,7 +320,7 @@ 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);
}