From: Mike Christie <mchristi@redhat.com>
To: syzbot <syzbot+24c12fa8d218ed26011a@syzkaller.appspotmail.com>,
axboe@kernel.dk, josef@toxicpanda.com,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
nbd@other.debian.org, syzkaller-bugs@googlegroups.com
Subject: Re: INFO: task hung in nbd_ioctl
Date: Tue, 1 Oct 2019 12:48:14 -0500 [thread overview]
Message-ID: <5D93915E.3090504@redhat.com> (raw)
In-Reply-To: <000000000000b1b1ee0593cce78f@google.com>
On 09/30/2019 05:39 PM, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: bb2aee77 Add linux-next specific files for 20190926
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=13385ca3600000
> kernel config: https://syzkaller.appspot.com/x/.config?x=e60af4ac5a01e964
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=24c12fa8d218ed26011a
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12abc2a3600000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11712c05600000
>
> The bug was bisected to:
>
> commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4
> Author: Mike Christie <mchristi@redhat.com>
> Date: Sun Aug 4 19:10:06 2019 +0000
>
> nbd: fix max number of supported devs
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1226f3c5600000
> final crash: https://syzkaller.appspot.com/x/report.txt?x=1126f3c5600000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1626f3c5600000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+24c12fa8d218ed26011a@syzkaller.appspotmail.com
> Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
>
> INFO: task syz-executor390:8778 can't die for more than 143 seconds.
> syz-executor390 D27432 8778 8777 0x00004004
> Call Trace:
> context_switch kernel/sched/core.c:3384 [inline]
> __schedule+0x828/0x1c20 kernel/sched/core.c:4065
> schedule+0xd9/0x260 kernel/sched/core.c:4132
> schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871
> do_wait_for_common kernel/sched/completion.c:83 [inline]
> __wait_for_common kernel/sched/completion.c:104 [inline]
> wait_for_common kernel/sched/completion.c:115 [inline]
> wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
> flush_workqueue+0x40f/0x14c0 kernel/workqueue.c:2826
> nbd_start_device_ioctl drivers/block/nbd.c:1272 [inline]
> __nbd_ioctl drivers/block/nbd.c:1347 [inline]
> nbd_ioctl+0xb2e/0xc44 drivers/block/nbd.c:1387
> __blkdev_driver_ioctl block/ioctl.c:304 [inline]
> blkdev_ioctl+0xedb/0x1c20 block/ioctl.c:606
> block_ioctl+0xee/0x130 fs/block_dev.c:1954
> vfs_ioctl fs/ioctl.c:47 [inline]
> file_ioctl fs/ioctl.c:539 [inline]
> do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726
> ksys_ioctl+0xab/0xd0 fs/ioctl.c:743
> __do_sys_ioctl fs/ioctl.c:750 [inline]
> __se_sys_ioctl fs/ioctl.c:748 [inline]
> __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748
> do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x4452d9
> Code: Bad RIP value.
> RSP: 002b:00007ffde928d288 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004452d9
> RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
> RBP: 0000000000000000 R08: 00000000004025b0 R09: 00000000004025b0
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402520
> R13: 00000000004025b0 R14: 0000000000000000 R15: 0000000000000000
> INFO: task syz-executor390:8778 blocked for more than 143 seconds.
> Not tainted 5.3.0-next-20190926 #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> syz-executor390 D27432 8778 8777 0x00004004
> Call Trace:
> context_switch kernel/sched/core.c:3384 [inline]
> __schedule+0x828/0x1c20 kernel/sched/core.c:4065
> schedule+0xd9/0x260 kernel/sched/core.c:4132
> schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871
> do_wait_for_common kernel/sched/completion.c:83 [inline]
> __wait_for_common kernel/sched/completion.c:104 [inline]
> wait_for_common kernel/sched/completion.c:115 [inline]
> wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
> flush_workqueue+0x40f/0x14c0 kernel/workqueue.c:2826
> nbd_start_device_ioctl drivers/block/nbd.c:1272 [inline]
> __nbd_ioctl drivers/block/nbd.c:1347 [inline]
> nbd_ioctl+0xb2e/0xc44 drivers/block/nbd.c:1387
> __blkdev_driver_ioctl block/ioctl.c:304 [inline]
> blkdev_ioctl+0xedb/0x1c20 block/ioctl.c:606
> block_ioctl+0xee/0x130 fs/block_dev.c:1954
> vfs_ioctl fs/ioctl.c:47 [inline]
> file_ioctl fs/ioctl.c:539 [inline]
> do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726
> ksys_ioctl+0xab/0xd0 fs/ioctl.c:743
> __do_sys_ioctl fs/ioctl.c:750 [inline]
> __se_sys_ioctl fs/ioctl.c:748 [inline]
> __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748
> do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x4452d9
> Code: Bad RIP value.
> RSP: 002b:00007ffde928d288 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004452d9
> RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
> RBP: 0000000000000000 R08: 00000000004025b0 R09: 00000000004025b0
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402520
> R13: 00000000004025b0 R14: 0000000000000000 R15: 0000000000000000
>
I will send a fix for this.
I had assumed that for every socket type a kernel_sock_shutdown would
break us out of sock_recvmsg call, but it looks like that's not the case.
next prev parent reply other threads:[~2019-10-01 17:48 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-30 22:39 INFO: task hung in nbd_ioctl syzbot
2019-10-01 17:48 ` Mike Christie [this message]
2019-10-01 21:19 ` Mike Christie
2019-10-17 14:03 ` Richard W.M. Jones
2019-10-17 15:47 ` Mike Christie
2019-10-17 16:28 ` Richard W.M. Jones
2019-10-17 16:36 ` Eric Biggers
2019-10-17 16:49 ` Richard W.M. Jones
2019-10-17 21:26 ` Mike Christie
2019-10-30 8:39 ` Wouter Verhelst
2019-10-30 8:41 ` Wouter Verhelst
-- strict thread matches above, loose matches on Subject: below --
2021-09-16 2:43 Hao Sun
2021-09-18 1:34 Hao Sun
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