Re: [syzbot] WARNING in __perf_install_in_context

From: Peter Zijlstra
Date: Mon May 17 2021 - 07:28:15 EST


On Mon, May 17, 2021 at 03:56:22AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 18a3c5f7 Merge tag 'for_linus' of git://git.kernel.org/pub..
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> console output: https://syzkaller.appspot.com/x/log.txt?x=1662c153d00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=b8ac1fe5995f69d7
> dashboard link: https://syzkaller.appspot.com/bug?extid=0fb24f56fa707081e4f2
> userspace arch: riscv64
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+0fb24f56fa707081e4f2@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 8643 at kernel/events/core.c:2781 __perf_install_in_context+0x1c0/0x47c kernel/events/core.c:2781
> Modules linked in:
> CPU: 1 PID: 8643 Comm: syz-executor.0 Not tainted 5.12.0-rc8-syzkaller-00011-g18a3c5f7abfd #0
> Hardware name: riscv-virtio,qemu (DT)

How serious should I take this thing? ARM64 and x86_64 don't show these
errors.