syzbot

 sign-in | mailing list | source | docs
🐞 Open [1499]
≡ Subsystems
🐞 Fixed [6516]
🐞 Invalid [16585]
⬇ Missing Backports [204]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

INFO: rcu detected stall in sys_wait4

Status: auto-closed as invalid on 2020/10/10 08:00
Subsystems: kernel
[Documentation on labels]
First crash: 1864d, last: 1864d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_wait4 (3) kernel 1 1 724d 724d 0/29 auto-obsoleted due to no activity on 2023/11/24 01:26
upstream INFO: rcu detected stall in sys_wait4 (2) kernel 1 1 1233d 1233d 0/29 auto-closed as invalid on 2022/07/03 11:21
upstream INFO: rcu detected stall in sys_wait4 (4) mm 1 C done done 2 462d 495d 26/29 fixed on 2024/07/12 01:55
linux-5.15 INFO: rcu detected stall in sys_wait4 1 1 432d 432d 0/3 auto-obsoleted due to no activity on 2024/09/21 03:35
upstream INFO: rcu detected stall in sys_wait4 (5) kernel 1 1 236d 236d 0/29 auto-obsoleted due to no activity on 2025/03/26 13:51
linux-6.1 INFO: rcu detected stall in sys_wait4 1 1 861d 861d 0/3 auto-obsoleted due to no activity on 2023/08/09 13:38

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=20a/1/0x4000000000000000 softirq=167612/167612 fqs=0 
	(t=10500 jiffies g=231485 q=86)
rcu: rcu_preempt kthread starved for 10500 jiffies! g231485 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I28912    10      2 0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x7d3/0xc40 kernel/sched/core.c:4178
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6944 Comm: syz-executor.1 Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_local_irq_restore+0x3a/0x50 arch/x86/include/asm/paravirt.h:765
Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 f0 c7 2b 89 e8 45 5d 5a 00 48 83 3d 9d 88 d2 07 00 74 0c 48 89 df 57 9d <0f> 1f 44 00 00 5b c3 0f 0b 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000007cd8 EFLAGS: 00000082
RAX: 1ffffffff12578fe RBX: 0000000000000082 RCX: dffffc0000000000
RDX: ffff888074a7c1c0 RSI: ffff88809f109300 RDI: 0000000000000082
RBP: 0000000000000001 R08: ffffffff869acc50 R09: fffff52000000f9c
R10: fffff52000000f9c R11: 0000000000000000 R12: ffff888074a7c1c0
R13: ffff88809f109300 R14: 00000000ffffffff R15: 0000000000000082
FS:  00000000019b6940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004dbc10 CR3: 0000000074a6c000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_is_held_type+0x87/0xe0 kernel/locking/lockdep.c:4998
 lock_is_held include/linux/lockdep.h:425 [inline]
 advance_sched+0x1be/0x8c0 net/sched/sch_taprio.c:704
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x47f/0x930 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb9/0x130 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:do_wait_thread kernel/exit.c:1377 [inline]
RIP: 0010:do_wait+0x2f0/0x690 kernel/exit.c:1449
Code: 89 c6 e8 b3 56 2d 00 45 85 ff 0f 85 be 02 00 00 48 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 54 60 6c 00 48 8b 6d 00 <49> 39 ed 74 1b e8 76 52 2d 00 eb b4 0f 1f 40 00 e8 6b 52 2d 00 eb
RSP: 0018:ffffc90002397d18 EFLAGS: 00000246
RAX: 1ffff11011c52cb1 RBX: ffffc90002397dd8 RCX: ffff888074a7c1c0
RDX: ffff888074a7c1c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff8880970faa08 R08: ffffffff81473c1d R09: ffffffff81475bec
R10: 0000000000000002 R11: ffff888074a7c1c0 R12: dffffc0000000000
R13: ffff888074a7c6b8 R14: ffff888074a7c1c0 R15: 0000000000000000
 kernel_wait4+0x1d1/0x2c0 kernel/exit.c:1621
 __do_sys_wait4 kernel/exit.c:1633 [inline]
 __se_sys_wait4 kernel/exit.c:1629 [inline]
 __x64_sys_wait4+0xc3/0x150 kernel/exit.c:1629
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4169ca
Code: Bad RIP value.
RSP: 002b:00007ffe906406a8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000011f5bf RCX: 00000000004169ca
RDX: 0000000040000001 RSI: 00007ffe906406e0 RDI: ffffffffffffffff
RBP: 0000000000001152 R08: 0000000000000001 R09: 00000000019b6940
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffe906406e0 R14: 000000000011f591 R15: 00007ffe906406f0
NMI backtrace for cpu 1
CPU: 1 PID: 23537 Comm: syz-executor.0 Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1f0/0x31e lib/dump_stack.c:118
 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x199/0x2a0 kernel/rcu/tree_stall.h:320
 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 rcu_pending kernel/rcu/tree.c:3489 [inline]
 rcu_sched_clock_irq+0x1928/0x1eb0 kernel/rcu/tree.c:2504
 update_process_times+0x12c/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:176 [inline]
 tick_sched_timer+0x254/0x410 kernel/time/tick-sched.c:1320
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb9/0x130 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:__sanitizer_cov_trace_pc+0x59/0x60 kernel/kcov.c:207
Code: e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 48 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a <c3> 66 0f 1f 44 00 00 4c 8b 04 24 65 48 8b 14 25 00 fe 01 00 65 8b
RSP: 0018:ffffc900023d7d98 EFLAGS: 00000246
RAX: ffffffff81698d96 RBX: 1ffff9200047afb9 RCX: 0000000000040000
RDX: ffffc90001ca9000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc900023d7e28 R08: ffffffff81698d66 R09: ffffed1015d06d11
R10: ffffed1015d06d11 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffffc900023d7dc8
 csd_lock_wait kernel/smp.c:108 [inline]
 smp_call_function_single+0x316/0x450 kernel/smp.c:382
 smp_call_function_many kernel/smp.c:577 [inline]
 smp_call_function kernel/smp.c:599 [inline]
 on_each_cpu+0x4d/0x1f0 kernel/smp.c:699
 clock_was_set+0x18/0x20 kernel/time/hrtimer.c:872
 do_settimeofday64+0x41e/0x520 kernel/time/timekeeping.c:1257
 __do_sys_clock_settime kernel/time/posix-timers.c:1079 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1067 [inline]
 __x64_sys_clock_settime+0x196/0x1c0 kernel/time/posix-timers.c:1067
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cba9
Code: Bad RIP value.
RSP: 002b:00007f7750e06c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00000000004dbbc0 RCX: 000000000045cba9
RDX: 0000000000000000 RSI: 0000000020000400 RDI: 0000000000000000
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000007b R14: 00000000004c352c R15: 00007f7750e076d4

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/07/12 07:53 upstream 0aea6d5c5be3 115e1930 .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.