syzbot


INFO: task hung in synchronize_rcu (2)

Status: closed as invalid on 2019/11/30 16:54
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1039d, last: 1038d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in synchronize_rcu (3) C done done 354 4d04h 803d 23/24 upstream: reported C repro on 2020/07/22 18:22
android-49 INFO: task hung in synchronize_rcu 1 1039d 1039d 0/3 auto-closed as invalid on 2020/03/28 16:57
linux-4.14 INFO: task hung in synchronize_rcu C error 158 22d 1061d 0/1 upstream: reported C repro on 2019/11/07 04:32
linux-4.19 INFO: task hung in synchronize_rcu C 67 4d11h 1059d 0/1 upstream: reported C repro on 2019/11/08 21:27
upstream INFO: task hung in synchronize_rcu syz done 1206 1039d 1065d 15/24 fixed on 2019/11/29 15:48
android-414 INFO: task hung in synchronize_rcu 1 1057d 1057d 0/1 auto-closed as invalid on 2020/03/10 10:42

Sample crash report:
INFO: task syz-executor.0:8046 blocked for more than 143 seconds.
      Not tainted 5.4.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D27416  8046   8037 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081
 schedule+0xdc/0x2b0 kernel/sched/core.c:4155
 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
 __wait_rcu_gp+0x225/0x2f0 kernel/rcu/update.c:374
 synchronize_rcu.part.0+0xcf/0xe0 kernel/rcu/tree.c:2768
 synchronize_rcu+0x27/0xa0 kernel/rcu/tree.c:2769
 tracepoint_synchronize_unregister include/linux/tracepoint.h:83 [inline]
 perf_trace_event_unreg.isra.0+0xcb/0x220 kernel/trace/trace_event_perf.c:168
 perf_trace_destroy+0xbc/0x100 kernel/trace/trace_event_perf.c:243
 tp_perf_event_destroy+0x16/0x20 kernel/events/core.c:8995
 _free_event+0x35c/0x1410 kernel/events/core.c:4615
 put_event+0x47/0x60 kernel/events/core.c:4709
 perf_event_release_kernel+0x772/0xef0 kernel/events/core.c:4824
 perf_release+0x37/0x50 kernel/events/core.c:4834
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413d81
Code: 89 44 24 10 e8 40 c1 04 00 48 8b 6c 24 18 48 83 c4 20 c3 48 8b 4c 24 30 48 89 0c 24 48 8b 4c 24 38 48 89 4c 24 08 48 89 44 24 <10> e8 99 0c 00 00 48 8b 44 24 40 eb b5 48 8b 44 24 40 eb ae 48 8b
RSP: 002b:00007fff9effb430 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413d81
RDX: 0000000000718060 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000071c980 R08: 00000000000142d2 R09: 00000000000142d2
R10: 00007fff9effb560 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000720bd8 R14: 0000000000720be0 R15: 00007fff9effb540

Showing all locks held in the system:
1 lock held by khungtaskd/1113:
 #0: ffffffff895a4080 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334
2 locks held by getty/7978:
 #0: ffff88802b6fd090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc900040322e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/7979:
 #0: ffff8880255d9090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000401a2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/7980:
 #0: ffff88801ea21090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000403a2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/7981:
 #0: ffff888025ede090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc900040362e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/7982:
 #0: ffff88802bb4d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000402e2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/7983:
 #0: ffff888021928090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000402a2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
2 locks held by getty/7984:
 #0: ffff88802c6a0090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000400a2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.0/8046:
 #0: ffffffff895e8e40 (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:241

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

NMI backtrace for cpu 3
CPU: 3 PID: 1113 Comm: khungtaskd Not tainted 5.4.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xb11/0x10c0 kernel/hung_task.c:289
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 3 to CPUs 0-2:
NMI backtrace for cpu 2 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
NMI backtrace for cpu 0
CPU: 0 PID: 8058 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:__lock_acquire+0x21f/0x4a00 kernel/locking/lockdep.c:3892
Code: 0a 40 80 fe 03 0f 8e 0f 38 00 00 0f b7 70 20 81 e6 ff 1f 00 00 44 39 e6 75 09 48 85 db 0f 85 fc 11 00 00 4c 03 95 60 ff ff ff <44> 89 e6 66 81 e6 ff 1f 49 8d 42 20 48 89 c2 48 89 85 50 ff ff ff
RSP: 0018:ffff88802d209c58 EFLAGS: 00000082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88800a730958
RBP: ffff88802d209d70 R08: 0000000000000001 R09: 0000000000000001
R10: ffff88800a730958 R11: ffff88800a7300c0 R12: 0000000000000051
R13: 0000000000000000 R14: ffff88802d2293d8 R15: 0000000000000001
FS:  00007f8708cf3700(0000) GS:ffff88802d200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 0000000071290000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167
 __run_hrtimer kernel/time/hrtimer.c:1516 [inline]
 __hrtimer_run_queues+0x3df/0xe40 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x4f/0x80 kernel/locking/spinlock.c:199
Code: c0 68 34 53 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 12 2a 99 01 00 74 20 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 e7 6b 96 f9 65 8b 05 18 14 48 78 85 c0 74 06 41
RSP: 0018:ffff888070f27588 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff12a668d RBX: ffffffff880b3de0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff88800a730954
RBP: ffff888070f27590 R08: ffff88800a7300c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88802d237380
R13: ffff88800a7300c0 R14: ffff88800a7300c0 R15: ffff88802d237398
 rq_unlock_irq kernel/sched/sched.h:1240 [inline]
 __schedule+0x150a/0x1f30 kernel/sched/core.c:4084
 preempt_schedule_common+0x4f/0xe0 kernel/sched/core.c:4236
 preempt_schedule+0x4b/0x60 kernel/sched/core.c:4261
 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50
 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock+0x3c/0x40 kernel/locking/spinlock.c:183
 spin_unlock include/linux/spinlock.h:378 [inline]
 zap_pte_range mm/memory.c:1130 [inline]
 zap_pmd_range mm/memory.c:1178 [inline]
 zap_pud_range mm/memory.c:1207 [inline]
 zap_p4d_range mm/memory.c:1228 [inline]
 unmap_page_range+0x10b1/0x2ac0 mm/memory.c:1249
 unmap_single_vma+0x19d/0x300 mm/memory.c:1294
 unmap_vmas+0x184/0x2f0 mm/memory.c:1326
 exit_mmap+0x2ba/0x530 mm/mmap.c:3161
 __mmput kernel/fork.c:1079 [inline]
 mmput+0x179/0x4d0 kernel/fork.c:1100
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x806/0x2ef0 kernel/exit.c:784
 do_group_exit+0x135/0x360 kernel/exit.c:895
 get_signal+0x47c/0x24f0 kernel/signal.c:2734
 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a759
Code: Bad RIP value.
RSP: 002b:00007f8708cf2c88 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000007 RBX: 000000000071c0f8 RCX: 000000000045a759
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 000000002001d000
RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f8708cf36d4
R13: 00000000004aec2b R14: 00000000006f1ca8 R15: 00000000ffffffff

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-qemu-upstream 2019/11/30 16:13 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/30 10:56 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/30 10:02 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/30 06:20 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/30 00:10 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/29 21:02 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/29 19:23 upstream 81b6b96475ac 3a75be00 .config log report
ci-qemu-upstream 2019/11/29 18:52 upstream 81b6b96475ac 3a75be00 .config log report
* Struck through repros no longer work on HEAD.