On Tue, Jun 8, 2021 at 11:47 AM Hao Xu <haoxu@xxxxxxxxxxxxxxxxx> wrote: > > 在 2021/6/5 上午4:22, syzbot 写道: > > syzbot has bisected this issue to: > > > > commit 24369c2e3bb06d8c4e71fd6ceaf4f8a01ae79b7c > > Author: Pavel Begunkov <asml.silence@xxxxxxxxx> > > Date: Tue Jan 28 00:15:48 2020 +0000 > > > > io_uring: add io-wq workqueue sharing > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17934777d00000 > > start commit: f88cd3fb Merge tag 'vfio-v5.13-rc5' of git://github.com/aw.. > > git tree: upstream > > final oops: https://syzkaller.appspot.com/x/report.txt?x=14534777d00000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=10534777d00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=82d85e75046e5e64 > > dashboard link: https://syzkaller.appspot.com/bug?extid=ea2f1484cffe5109dc10 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d5772fd00000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10525947d00000 > > > > Reported-by: syzbot+ea2f1484cffe5109dc10@xxxxxxxxxxxxxxxxxxxxxxxxx > > Fixes: 24369c2e3bb0 ("io_uring: add io-wq workqueue sharing") > > > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > > This is not a bug, the repro program first set RLIMIT_NPROC to 0, then > submits an unbound work whcih raises a warning of > WARN_ON_ONCE(!acct->max_workers). Since unbound->max_workers is > task_rlimit(current, RLIMIT_NPROC), so it is expected. Hi Hao, Then this is a mis-use of WARN_ON. If this check is intended for end users, it needs to use pr_err (also print understandable message and no stack trace which is most likely not useful for end users): https://elixir.bootlin.com/linux/v5.13-rc5/source/include/asm-generic/bug.h#L71
