On Tue 30-04-24 08:04:03, syzbot wrote:
syzbot has bisected this issue to:So I'm not sure the bisect is correct since the change is looking harmless.
commit 67d7d8ad99beccd9fe92d585b87f1760dc9018e3
Author: Baokun Li <libaokun1@xxxxxxxxxx>
Date: Thu Jun 16 02:13:56 2022 +0000
ext4: fix use-after-free in ext4_xattr_set_entry
But it is sufficiently related that there indeed may be some relationship.
Anyway, the kernel log has:
[ 44.932900][ T1063] EXT4-fs warning (device loop0): ext4_evict_inode:297: xattr delete (err -12)
[ 44.943316][ T1063] EXT4-fs (loop0): unmounting filesystem.
[ 44.949531][ T1063] ------------[ cut here ]------------
[ 44.955050][ T1063] WARNING: CPU: 0 PID: 1063 at fs/mbcache.c:409 mb_cache_destroy+0xda/0x110
So ext4_xattr_delete_inode() called when removing inode has failed with
ENOMEM and later mb_cache_destroy() was eventually complaining about having
mbcache entry with increased refcount. So likely some error cleanup path is
forgetting to drop mbcache entry reference somewhere but at this point I
cannot find where. We'll likely need to play with the reproducer to debug
that. Baokun, any chance for looking into this?
Honza