Re: INFO: rcu detected stall in corrupted (3)

[Tetsuo Handa]

On 2019/03/30 7:34, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:ÂÂÂ 8c2ffd91 Linux 5.1-rc2
> git tree:ÂÂÂÂÂÂ upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15099d2b200000
> kernel config:Â https://syzkaller.appspot.com/x/.config?x=8dcdce25ea72bedf
> dashboard link: https://syzkaller.appspot.com/bug?extid=65cecdd27b726c261799
> compiler:ÂÂÂÂÂÂ gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:ÂÂÂÂÂ https://syzkaller.appspot.com/x/repro.syz?x=17d3c67d200000
> C reproducer:ÂÂ https://syzkaller.appspot.com/x/repro.c?x=11d4f317200000
> 
> Bisection is inconclusive: the bug happens on the oldest tested release.

This reproducer does sched_setattr(SCHED_DEADLINE) with bogus value, as with
a reproducer for "INFO: rcu detected stall in sys_sendfile64" did.

  sched_setattr(0, {size=0, sched_policy=0x6 /* SCHED_DEADLINE */, sched_flags=0, sched_nice=0, sched_priority=0, sched_runtime=65535, sched_deadline=4611686018427453437, sched_period=0}, 0) = 0

#syz invalid