Re: [syzbot] [mm?] [bcachefs?] WARNING in lock_list_lru_of_memcg

Andrew Morton
2025-02-14T23:23:59Z

On Fri, 14 Feb 2025 10:11:19 -0800 syzbot <syzbot+38a0cbd267eff2d286ff@syzkaller.appspotmail.com> wrote:

> syzbot has found a reproducer for the following issue on:

Thanks. I doubt if bcachefs is implicated in this?

> HEAD commit: 128c8f96eb86 Merge tag 'drm-fixes-2025-02-14' of https://g..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=148019a4580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=c776e555cfbdb82d
> dashboard link: https://syzkaller.appspot.com/bug?extid=38a0cbd267eff2d286ff
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12328bf8580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-128c8f96.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/a97f78ac821e/vmlinux-128c8f96.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/f451cf16fc9f/bzImage-128c8f96.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/a7da783f97cf/mount_3.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+38a0cbd267eff2d286ff@syzkaller.appspotmail.com
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 5459 at mm/list_lru.c:96 lock_list_lru_of_memcg+0x39e/0x4d0 mm/list_lru.c:96

VM_WARN_ON(!css_is_dying(&memcg->css));

>
> ...
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