ext4: fix checking of directory entry validity for inline directories

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>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index cb2eb1967e7308bfbe3cc58375d58bef8c549375..b92571beab72786c94668fb6d3d3d8596f545f16 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1396,8 +1396,8 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
                    ext4_match(dir, 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;
@@ -2482,7 +2482,7 @@ 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)