syzbot


INFO: task hung in nbd_ioctl

Status: fixed on 2019/11/06 12:39
Subsystems: nbd
[Documentation on labels]
Reported-by: syzbot+24c12fa8d218ed26011a@syzkaller.appspotmail.com
Fix commit: cf1b2326b734 nbd: verify socket is supported during setup
First crash: 1754d, last: 1682d
Cause bisection: introduced by (bisect log) :
commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4
Author: Mike Christie <mchristi@redhat.com>
Date: Sun Aug 4 19:10:06 2019 +0000

  nbd: fix max number of supported devs

Crash: INFO: task hung in nbd_ioctl (log)
Repro: C syz .config
  
Discussions (8)
Title Replies (including bot) Last reply
[PATCH 4.19 000/149] 4.19.82-stable review 169 (169) 2019/11/11 09:36
[PATCH 5.3 000/163] 5.3.9-stable review 174 (174) 2019/11/06 10:49
[PATCH 4.14 00/95] 4.14.152-stable review 102 (102) 2019/11/05 23:37
[PATCH AUTOSEL 4.14 01/24] arm64: dts: Fix gpio to pinmux mapping 24 (24) 2019/10/30 15:55
[PATCH AUTOSEL 4.19 01/38] regulator: of: fix suspend-min/max-voltage parsing 38 (38) 2019/10/30 15:54
INFO: task hung in nbd_ioctl 10 (11) 2019/10/30 08:41
[PATCH] nbd: verify socket is supported during setup 3 (3) 2019/10/25 20:37
[PATCH] nbd: fix hang in NBD_DO_IT ioctl error handling 2 (2) 2019/10/17 16:09
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in nbd_ioctl C done 18 1630d 1704d 1/1 fixed on 2019/12/28 10:32
linux-4.14 INFO: task hung in nbd_ioctl (2) C done 16 1377d 1623d 1/1 fixed on 2020/10/21 11:01
upstream INFO: task hung in nbd_ioctl (2) nbd 37 1385d 1438d 15/28 fixed on 2020/09/25 01:17
linux-5.15 INFO: task hung in nbd_ioctl origin:upstream C error 11 48d 353d 0/3 upstream: reported C repro on 2023/06/26 06:58
linux-6.1 INFO: task hung in nbd_ioctl origin:upstream C 7 15d 416d 0/3 upstream: reported C repro on 2023/04/23 23:29
linux-4.19 INFO: task hung in nbd_ioctl C error 79 492d 1706d 0/1 upstream: reported C repro on 2019/10/12 13:11
upstream INFO: task hung in nbd_ioctl (3) nbd C done unreliable 123 4d19h 1354d 0/28 upstream: reported C repro on 2020/09/28 07:17
linux-4.14 INFO: task hung in nbd_ioctl (3) C inconclusive 12 757d 1308d 0/1 upstream: reported C repro on 2020/11/13 07:37

Sample crash report:
INFO: task syz-executor039:7883 blocked for more than 143 seconds.
      Not tainted 5.4.0-rc4+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor039 D27984  7883   7880 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3384 [inline]
 __schedule+0x74b/0xb80 kernel/sched/core.c:4069
 schedule+0x131/0x1e0 kernel/sched/core.c:4136
 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871
 do_wait_for_common+0x2e7/0x4d0 kernel/sched/completion.c:83
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x47/0x60 kernel/sched/completion.c:136
 flush_workqueue+0x60d/0x14b0 kernel/workqueue.c:2826
 nbd_start_device_ioctl drivers/block/nbd.c:1272 [inline]
 __nbd_ioctl drivers/block/nbd.c:1347 [inline]
 nbd_ioctl+0x9d2/0xac0 drivers/block/nbd.c:1387
 __blkdev_driver_ioctl block/ioctl.c:304 [inline]
 blkdev_ioctl+0x807/0x2980 block/ioctl.c:606
 block_ioctl+0xbd/0x100 fs/block_dev.c:1954
 do_vfs_ioctl+0x744/0x1730 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4496e9
Code: 00 61 64 64 69 6e 67 20 61 20 72 75 6c 65 73 65 74 2d 73 70 65 63 69 66 69 63 20 22 6d 61 69 6e 22 20 71 75 65 75 65 00 00 70 <72> 6f 63 65 73 73 42 61 74 63 68 3a 20 62 61 74 63 68 20 6f 66 20
RSP: 002b:00007fd715da2ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dac48 RCX: 00000000004496e9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000005
RBP: 00000000006dac40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac4c
R13: 00007ffd73e6239f R14: 00007fd715da39c0 R15: 20c49ba5e353f7cf

Showing all locks held in the system:
1 lock held by khungtaskd/1070:
 #0: ffffffff888d3f80 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207
2 locks held by kworker/u5:0/1527:
 #0: ffff88809fa37d28 ((wq_completion)knbd0-recv){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline]
 #0: ffff88809fa37d28 ((wq_completion)knbd0-recv){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242
 #1: ffff8880a637fd78 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244
1 lock held by rsyslogd/7770:
 #0: ffff8880a04f7420 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801
2 locks held by getty/7860:
 #0: ffff88809b3bd090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156
2 locks held by getty/7861:
 #0: ffff888090daf090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156
2 locks held by getty/7862:
 #0: ffff8880a3a20090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156
2 locks held by getty/7863:
 #0: ffff8880a7bcc090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f152e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156
2 locks held by getty/7864:
 #0: ffff8880a35b0090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156
2 locks held by getty/7865:
 #0: ffff8880a2541090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156
2 locks held by getty/7866:
 #0: ffff88809b0f8090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272
 #1: ffffc90005f012e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1070 Comm: khungtaskd Not tainted 5.4.0-rc4+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xbb9/0xbd0 kernel/hung_task.c:289
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60

Crashes (71):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/22 14:19 upstream 3b7c59a1950c c59a7cd8 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/10/06 18:52 upstream 43b815c6a8e7 f3f7d9c8 .config console log report syz C ci-upstream-kasan-gce-root
2019/09/28 00:50 linux-next bb2aee77c82d d8074e0b .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/11/05 08:34 upstream a99d8080aaf3 76630fc9 .config console log report ci-upstream-kasan-gce-root
2019/10/30 11:27 upstream 23fdb198ae81 5ea87a66 .config console log report ci-upstream-kasan-gce-root
2019/10/26 04:20 upstream 8caacaad78b6 c2e837da .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/25 22:34 upstream 39a38bcba4ab c2e837da .config console log report ci-upstream-kasan-gce-root
2019/10/25 09:09 upstream 39a38bcba4ab d01bb02a .config console log report ci-upstream-kasan-gce-smack-root
2019/10/22 08:11 upstream 7d194c2100ad c59a7cd8 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/21 07:15 upstream 4fe34d61a3a9 8c88c9c1 .config console log report ci-upstream-kasan-gce-root
2019/10/19 12:01 upstream b9959c7a347d 8c88c9c1 .config console log report ci-upstream-kasan-gce-smack-root
2019/10/19 10:01 upstream b9959c7a347d 8c88c9c1 .config console log report ci-upstream-kasan-gce-root
2019/10/18 19:06 upstream 0e2adab6cf28 8c88c9c1 .config console log report ci-upstream-kasan-gce-root
2019/10/18 06:56 upstream 283ea345934d 8c88c9c1 .config console log report ci-upstream-kasan-gce-smack-root
2019/10/17 07:56 upstream bc88f85c6c09 8c88c9c1 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/16 16:06 upstream 3b1f00aceb7a d4ea592f .config console log report ci-upstream-kasan-gce-smack-root
2019/10/16 13:41 upstream 3b1f00aceb7a d4ea592f .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/13 23:44 upstream da94001239cc 2f661ec4 .config console log report ci-upstream-kasan-gce-root
2019/10/12 04:54 upstream 9e208aa06c21 426631dd .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/11 13:00 upstream fb20da6af705 1a3bad90 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/06 17:46 upstream 43b815c6a8e7 f3f7d9c8 .config console log report ci-upstream-kasan-gce-smack-root
2019/10/06 11:13 upstream 43b815c6a8e7 f3f7d9c8 .config console log report ci-upstream-kasan-gce-root
2019/10/06 07:25 upstream 4ea655343ce4 f3f7d9c8 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/06 06:53 upstream 4ea655343ce4 f3f7d9c8 .config console log report ci-upstream-kasan-gce-smack-root
2019/10/05 04:29 upstream b145b0eb2031 f3f7d9c8 .config console log report ci-upstream-kasan-gce-root
2019/10/05 02:43 upstream b145b0eb2031 f3f7d9c8 .config console log report ci-upstream-kasan-gce-smack-root
2019/10/05 00:45 upstream b145b0eb2031 f3f7d9c8 .config console log report ci-upstream-kasan-gce-root
2019/10/04 11:09 upstream cc3a7bfe62b9 fc17ba49 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/02 21:31 upstream 54ecb8f7028c 2e29b534 .config console log report ci-upstream-kasan-gce-root
2019/10/01 22:33 upstream 54ecb8f7028c b7a87a83 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/01 04:46 upstream 54ecb8f7028c c7a4fb99 .config console log report ci-upstream-kasan-gce-selinux-root
2019/09/30 21:54 upstream 97f9a3c4eee5 c7a4fb99 .config console log report ci-upstream-kasan-gce-smack-root
2019/09/29 13:06 upstream 02dc96ef6c25 c1ad5441 .config console log report ci-upstream-kasan-gce-selinux-root
2019/09/27 06:04 upstream cbafe18c7102 2f1548bc .config console log report ci-upstream-kasan-gce-smack-root
2019/09/24 06:19 upstream e94f8ccde471 c68252d2 .config console log report ci-upstream-kasan-gce-root
2019/09/22 18:31 upstream f7c3bf8fa7e5 d96e88f3 .config console log report ci-upstream-kasan-gce-selinux-root
2019/09/21 22:53 upstream 227c3e9eb5cf d96e88f3 .config console log report ci-upstream-kasan-gce-root
2019/09/18 19:17 upstream 35f7a9526615 c2dcd700 .config console log report ci-upstream-kasan-gce-selinux-root
2019/10/18 13:32 linux-next c4b9850b3676 8c88c9c1 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/16 05:05 linux-next 0e9d28bc6c81 d4ea592f .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/14 04:58 linux-next 8ada228ac7ed 2f661ec4 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/13 08:05 linux-next 8ada228ac7ed 426631dd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/13 04:43 linux-next 8ada228ac7ed 426631dd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/10 13:35 linux-next 4a9e93dbc796 a4efa8c0 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/07 04:08 linux-next 311ef88adfa3 f3f7d9c8 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/06 11:57 linux-next 311ef88adfa3 f3f7d9c8 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/10/06 11:03 linux-next 311ef88adfa3 f3f7d9c8 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/27 20:39 linux-next bb2aee77c82d d8074e0b .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/21 20:17 linux-next b5b3bd898ba9 d96e88f3 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/14 22:03 linux-next 6d028043b55e 32d59357 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/14 18:57 linux-next 6d028043b55e 32d59357 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/14 13:46 linux-next 6d028043b55e 32d59357 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/12 22:46 linux-next 6d028043b55e 0b7672ee .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/12 07:08 linux-next 6d028043b55e f4e53c10 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/11 19:02 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/11 01:56 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/10 02:10 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/08 20:33 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/07 22:12 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/07 02:23 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
2019/09/06 08:08 linux-next 6d028043b55e 040fda58 .config console log report ci-upstream-linux-next-kasan-gce-root
2019/08/30 12:49 linux-next ed2393ca0910 fd37b39e .config console log report ci-upstream-linux-next-kasan-gce-root
2019/08/30 03:54 linux-next ed2393ca0910 fd37b39e .config console log report ci-upstream-linux-next-kasan-gce-root
2019/08/30 01:52 linux-next ed2393ca0910 fd37b39e .config console log report ci-upstream-linux-next-kasan-gce-root
2019/08/24 20:16 linux-next 9733a7c62c66 78ded196 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.