Re: [syzbot] INFO: task hung in synchronize_rcu (3)

[Paolo Bonzini]

On 5/10/22 15:45, Sean Christopherson wrote:
> >      KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
> >
> > bisection log:https://syzkaller.appspot.com/x/bisect.txt?x=16dc2e49f00000
> > start commit:   ea4424be1688 Merge tag 'mtd/fixes-for-5.17-rc8' of git://g..
> > git tree:       upstream
> > kernel config:https://syzkaller.appspot.com/x/.config?x=442f8ac61e60a75e
> > dashboard link:https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
> > syz repro:https://syzkaller.appspot.com/x/repro.syz?x=1685af9e700000
> > C reproducer:https://syzkaller.appspot.com/x/repro.c?x=11b09df1700000
> >
> > If the result looks correct, please mark the issue as fixed by replying with:
> >
> > #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
> >
> > For information about bisection process see:https://goo.gl/tpsmEJ#bisection
> #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()

Are you sure? The hang is in synchronize_*rcu* and the testcase is 
unrelated to KVM.  It seems like the testcase is not 100% reproducible.

Paolo