Re: [syzbot] [bcachefs?] [rcu?] BUG: unable to handle kernel NULL pointer dereference in rcu_core (3)

From: Boqun Feng
Date: Wed Jun 11 2025 - 16:59:00 EST


On Wed, Jun 11, 2025 at 12:57:04PM -0700, syzbot wrote:
> Hello,
>
> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
>
> Reported-by: syzbot+80e5d6f453f14a53383a@xxxxxxxxxxxxxxxxxxxxxxxxx
> Tested-by: syzbot+80e5d6f453f14a53383a@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> Tested on:
>
> commit: 488ef356 KEYS: Invert FINAL_PUT bit
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=129a660c580000

Is there a way to see the whole console output? If Ulad's patch fixes
the exact issue, we should be able to see a WARN_ON_ONCE() triggered.

Regards,
Boqun

> kernel config: https://syzkaller.appspot.com/x/.config?x=713d218acd33d94
> dashboard link: https://syzkaller.appspot.com/bug?extid=80e5d6f453f14a53383a
> compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
> patch: https://syzkaller.appspot.com/x/patch.diff?x=170e460c580000
>
> Note: testing is done by a robot and is best-effort only.
>