The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7303cb5bfe845f7d43cd9b2dbd37dbb266efda9b Mon Sep 17 00:00:00 2001
From: Jan Kara jack@suse.cz Date: Fri, 31 Jul 2020 18:21:35 +0200 Subject: [PATCH] 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 cb2eb1967e73..b92571beab72 100644 --- 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)