tree 20fc38556e27c4ba6aa90b14f1390c18f1c63d0c
parent a2e1484ed6dc5bca7defdfdb97818bcb9fc69e6a
author Theodore Ts'o <tytso@mit.edu> 1573181021 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1575495268 +0100

ext4: add more paranoia checking in ext4_expand_extra_isize handling

commit 4ea99936a1630f51fc3a2d61a58ec4a1c4b7d55a upstream.

It's possible to specify a non-zero s_want_extra_isize via debugging
option, and this can cause bad things(tm) to happen when using a file
system with an inode size of 128 bytes.

Add better checking when the file system is mounted, as well as when
we are actually doing the trying to do the inode expansion.

Link: https://lore.kernel.org/r/20191110121510.GH23325@mit.edu
Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com
Reported-by: syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com
Reported-by: syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>