Commit a5d3f789 authored Jul 31, 2020 by Jan Kara Committed by Greg Kroah-Hartman Aug 26, 2020

ext4: fix checking of directory entry validity for inline directories



commit 7303cb5bfe845f7d43cd9b2dbd37dbb266efda9b upstream.

ext4_search_dir() and ext4_generic_delete_entry() can be called both for
standard director blocks and for inline directories stored inside inode
or inline xattr space. For the second case we didn't call
ext4_check_dir_entry() with proper constraints that could result in
accepting corrupted directory entry as well as false positive filesystem
errors like:

EXT4-fs error (device dm-0): ext4_search_dir:1395: inode #28320400:
block 113246792: comm dockerd: bad entry in directory: directory entry too
close to block end - offset=0, inode=28320403, rec_len=32, name_len=8,
size=4096

Fix the arguments passed to ext4_check_dir_entry().

Fixes: 109ba779d6cc ("ext4: check for directory entries too close to block end")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200731162135.8080-1-jack@suse.cz


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c666936d

fs/ext4/namei.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1309,8 +1309,8 @@ int ext4_search_dir(struct buffer_head bh, char search_buf, int buf_size,
		ext4_match(fname, de)) {
		/* found a match - just to be sure, do
		* a full check */
		if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
		bh->b_size, offset))
		if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
		buf_size, offset))
		return -1;
		*res_dir = de;
		return 1;
		@@ -2344,7 +2344,7 @@ int ext4_generic_delete_entry(handle_t *handle,
		de = (struct ext4_dir_entry_2 *)entry_buf;
		while (i < buf_size - csum_size) {
		if (ext4_check_dir_entry(dir, NULL, de, bh,
		bh->b_data, bh->b_size, i))
		entry_buf, buf_size, i))
		return -EFSCORRUPTED;
		if (de == de_del) {
		if (pde)