Re: INFO: task hung in io_uring_cancel_sqpoll

From: Palash Oswal <oswalpalash@gmail.com>
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	io-uring@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	syzbot+11bf59db879676f59e52@syzkaller.appspotmail.com
Subject: Re: INFO: task hung in io_uring_cancel_sqpoll
Date: Fri, 30 Apr 2021 20:41:45 +0530	[thread overview]
Message-ID: <CAGyP=7eN4Eu2RwUQvXOYwaXAfYmxhU1gmQ9adSVUOmJNE+=teQ@mail.gmail.com> (raw)
In-Reply-To: <6d682c9d-a3ec-ec74-c8be-89e1ea5e24ca@gmail.com>

On Fri, Apr 30, 2021 at 8:37 PM Pavel Begunkov <asml.silence@gmail.com> wrote:
>
> On 4/30/21 4:02 PM, Palash Oswal wrote:
> > On Fri, Apr 30, 2021 at 8:03 PM Pavel Begunkov <asml.silence@gmail.com> wrote:
> >>
> >> On 4/30/21 3:21 PM, Palash Oswal wrote:
> >>> On Thursday, March 18, 2021 at 9:40:21 PM UTC+5:30 syzbot wrote:
> >>>>
> >>>> Hello,
> >>>>
> >>>> syzbot found the following issue on:
> >>>>
> >>>> HEAD commit: 0d7588ab riscv: process: Fix no prototype for arch_dup_tas..
> >>>> 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=12dde5aed00000
> >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=81c0b708b31626cc
> >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=11bf59db879676f59e52
> >>>> userspace arch: riscv64
> >>>> CC: [asml.s...@gmail.com ax...@kernel.dk io-u...@vger.kernel.org linux-...@vger.kernel.org]
> >>>>
> >>>> Unfortunately, I don't have any reproducer for this issue yet.
> >>
> >> There was so many fixes in 5.12 after this revision, including sqpoll
> >> cancellation related... Can you try something more up-to-date? Like
> >> released 5.12 or for-next
> >>
> >
> > The reproducer works for 5.12.
>
> Ok, any chance you have syz repro as well? it's easier to read
>
> >


Syzkaller reproducer:
# {Threaded:false Collide:false Repeat:true RepeatTimes:0 Procs:1
Slowdown:1 Sandbox: Fault:false FaultCall:-1 FaultNth:0 Leak:false
NetInjection:false NetDevices:false NetReset:false Cgroups:false
BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false USB:false
VhciInjection:false Wifi:false IEEE802154:false Sysctl:false
UseTmpDir:false HandleSegv:false Repro:false Trace:false}
r0 = syz_io_uring_setup(0x7987, &(0x7f0000000200)={0x0, 0x0, 0x2},
&(0x7f0000400000/0xc00000)=nil, &(0x7f0000ffd000/0x3000)=nil,
&(0x7f00000000c0)=<r1=>0x0, &(0x7f00000001c0)=<r2=>0x0)
syz_io_uring_submit(r1, r2, &(0x7f0000000180)=@IORING_OP_TIMEOUT={0xb,
0x1, 0x0, 0x0, 0x4, &(0x7f0000000140)={0x77359400}}, 0x1)
syz_io_uring_setup(0x4bf1, &(0x7f0000000540)={0x0, 0x0, 0x36, 0x0,
0x0, 0x0, r0}, &(0x7f0000ffd000/0x2000)=nil,
&(0x7f0000ffc000/0x1000)=nil, 0x0, 0x0)