ext4: Fix deadlock during directory rename
authorJan Kara <jack@suse.cz>
Wed, 1 Mar 2023 14:10:04 +0000 (15:10 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 17 Mar 2023 07:50:29 +0000 (08:50 +0100)
commit2ef7f829214fa8f428d953b49557b89b2b02db66
tree11c9744ef8452b340d6beb63ec06b834fdd38c79
parentdc7d4b1a6568652f51ee45b1a1e3531f1186a552
ext4: Fix deadlock during directory rename

[ Upstream commit 3c92792da8506a295afb6d032b4476e46f979725 ]

As lockdep properly warns, we should not be locking i_rwsem while having
transactions started as the proper lock ordering used by all directory
handling operations is i_rwsem -> transaction start. Fix the lock
ordering by moving the locking of the directory earlier in
ext4_rename().

Reported-by: syzbot+9d16c39efb5fade84574@syzkaller.appspotmail.com
Fixes: 0813299c586b ("ext4: Fix possible corruption when moving a directory")
Link: https://syzkaller.appspot.com/bug?extid=9d16c39efb5fade84574
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230301141004.15087-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fs/ext4/namei.c