Re: [syzbot] INFO: task hung in perf_event_free_task

From: Peter Zijlstra
Date: Wed Apr 21 2021 - 05:32:36 EST


On Tue, Apr 20, 2021 at 02:10:22AM -0700, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 7af08140 Revert "gcov: clang: fix clang-11+ build"
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15416871d00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=c0a6882014fd3d45
> dashboard link: https://syzkaller.appspot.com/bug?extid=7692cea7450c97fa2a0a
> compiler: Debian clang version 11.0.1-2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=145c9ffed00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12de31ded00000

When I build that C file and run it, it completes. AFAICT that's not the
expected outcome given we're looking for a hung-task scenario. Hmm?