syzbot


INFO: task hung in nbd_ioctl

Status: upstream: reported C repro on 2023/04/23 23:29
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+01dac5a170e34de1cd4b@syzkaller.appspotmail.com
First crash: 396d, last: 30d
Bug presence (1)
Date Name Commit Repro Result
2023/06/26 upstream (ToT) 88afbb21d4b3 C [report] INFO: task hung in nbd_ioctl
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in nbd_ioctl C done 18 1610d 1684d 1/1 fixed on 2019/12/28 10:32
linux-4.14 INFO: task hung in nbd_ioctl (2) C done 16 1357d 1602d 1/1 fixed on 2020/10/21 11:01
upstream INFO: task hung in nbd_ioctl (2) nbd 37 1364d 1417d 15/26 fixed on 2020/09/25 01:17
upstream INFO: task hung in nbd_ioctl nbd C done 71 1661d 1697d 13/26 fixed on 2019/11/06 12:39
linux-5.15 INFO: task hung in nbd_ioctl origin:upstream C error 11 27d 332d 0/3 upstream: reported C repro on 2023/06/26 06:58
linux-4.19 INFO: task hung in nbd_ioctl C error 79 471d 1685d 0/1 upstream: reported C repro on 2019/10/12 13:11
upstream INFO: task hung in nbd_ioctl (3) nbd C done unreliable 121 12d 1333d 0/26 upstream: reported C repro on 2020/09/28 07:17
linux-4.14 INFO: task hung in nbd_ioctl (3) C inconclusive 12 736d 1287d 0/1 upstream: reported C repro on 2020/11/13 07:37
upstream INFO: task can't die in nbd_ioctl nbd C done 7 40d 1326d 0/26 upstream: reported C repro on 2020/10/05 07:20
Fix bisection attempts (7)
Created Duration User Patch Repo Result
2024/04/23 17:21 2h30m bisect fix linux-6.1.y job log (0) log
2024/03/15 00:41 1h28m bisect fix linux-6.1.y job log (0) log
2024/01/15 01:23 1h39m bisect fix linux-6.1.y job log (0) log
2023/12/15 20:12 1h44m bisect fix linux-6.1.y job log (0) log
2023/11/14 19:17 1h24m bisect fix linux-6.1.y job log (0) log
2023/10/12 20:31 3h36m bisect fix linux-6.1.y job log (0) log
2023/09/03 14:21 1h40m bisect fix linux-6.1.y job log (0) log

Sample crash report:
INFO: task syz-executor158:3563 blocked for more than 143 seconds.
      Not tainted 6.1.35-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor158 state:D stack:26184 pid:3563  ppid:3562   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x132c/0x4330 kernel/sched/core.c:6554
 schedule+0xbf/0x180 kernel/sched/core.c:6630
 schedule_timeout+0xac/0x300 kernel/time/timer.c:1911
 do_wait_for_common+0x441/0x5e0 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x46/0x60 kernel/sched/completion.c:138
 __flush_workqueue+0x737/0x1610 kernel/workqueue.c:2861
 nbd_start_device_ioctl drivers/block/nbd.c:1425 [inline]
 __nbd_ioctl drivers/block/nbd.c:1487 [inline]
 nbd_ioctl+0xaf6/0xe70 drivers/block/nbd.c:1527
 blkdev_ioctl+0x3a9/0x760 block/ioctl.c:615
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f105e767389
RSP: 002b:00007ffe3d311a48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f105e767389
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe3d311be8 R09: 00007ffe3d311be8
R10: 00007ffe3d311be8 R11: 0000000000000246 R12: 00007f105e7266a0
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cf27470 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cf27c70 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
 #0: ffffffff8cf272a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u5:0/47:
 #0: ffff88801f953938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0
 #1: ffffc90000b87d20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264
2 locks held by getty/3303:
 #0: ffff8880213cc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2177
2 locks held by kworker/u4:0/3566:
 #0: ffff8880b9839dd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #1: ffff8880b9827788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x43d/0x770 kernel/sched/psi.c:952

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.35-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf18/0xf60 kernel/hung_task.c:377
 kthread+0x26e/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3566 Comm: kworker/u4:0 Not tainted 6.1.35-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:static_obj kernel/locking/lockdep.c:841 [inline]
RIP: 0010:lockdep_init_map_type+0x22e/0x8d0 kernel/locking/lockdep.c:4840
Code: 10 00 74 16 48 c7 c7 c0 e5 d5 8c e8 fc 71 76 00 48 ba 00 00 00 00 00 fc ff df 48 c7 c0 00 60 02 92 49 39 c7 0f 83 65 ff ff ff <4c> 39 3d 0b 38 6c 0b 0f 87 58 ff ff ff 4c 89 ff e8 8d 06 00 00 48
RSP: 0018:ffffc9000398f960 EFLAGS: 00000287
RAX: ffffffff92026000 RBX: ffffc9000398faaa RCX: ffffffff91a83103
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc9000398faa9
RBP: ffffc9000398fa28 R08: dffffc0000000000 R09: ffffc9000398fa90
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc9000398fa88
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff91ac8400
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558729454600 CR3: 000000000cc8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_init_map_waits include/linux/lockdep.h:191 [inline]
 lockdep_init_map_wait include/linux/lockdep.h:198 [inline]
 lockdep_init_map include/linux/lockdep.h:204 [inline]
 do_init_timer kernel/time/timer.c:850 [inline]
 init_timer_on_stack_key kernel/time/timer.c:806 [inline]
 schedule_timeout+0x1a0/0x300 kernel/time/timer.c:1933
 toggle_allocation_gate+0x23b/0x480 mm/kfence/core.c:811
 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289
 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436
 kthread+0x26e/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/26 04:49 linux-6.1.y e84a4e368abe 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in nbd_ioctl
2023/06/26 06:57 linux-6.1.y e84a4e368abe 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in nbd_ioctl
2024/03/22 15:00 linux-6.1.y d7543167affd 4b6cdce6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in nbd_ioctl
2024/03/15 15:32 linux-6.1.y 61adba85cc40 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in nbd_ioctl
2024/02/09 20:05 linux-6.1.y f1bb70486c9c 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in nbd_ioctl
2023/06/25 18:53 linux-6.1.y e84a4e368abe 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in nbd_ioctl
2023/04/23 23:29 linux-6.1.y f17b0ab65d17 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in nbd_ioctl
* Struck through repros no longer work on HEAD.