Messages in this thread | | | Date | Fri, 3 May 2024 09:54:56 +0800 | Subject | Re: [syzbot] [ext4?] WARNING in mb_cache_destroy | From | Baokun Li <> |
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On 2024/5/2 18:33, Jan Kara wrote: > On Tue 30-04-24 08:04:03, syzbot wrote: >> syzbot has bisected this issue to: >> >> commit 67d7d8ad99beccd9fe92d585b87f1760dc9018e3 >> Author: Baokun Li <libaokun1@huawei.com> >> Date: Thu Jun 16 02:13:56 2022 +0000 >> >> ext4: fix use-after-free in ext4_xattr_set_entry > So I'm not sure the bisect is correct since the change is looking harmless. > 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
Hi Honza,
Sorry for the late reply, the first two days were May Day holidays. Thanks for the heads up, I'll take a look at this soon.
Regards, Baokun
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