INFO: rcu detected stall in garp_join

INFO: rcu detected stall in garp_join_timer
Status: auto-closed as invalid on 2020/06/12 11:13
Reported-by: syzbot+e3431279540f468dc0bc@syzkaller.appspotmail.com
First crash: 395d, last: 380d

similar bugs (5):
Kernel	Title	Count	Last	Reported	Patched	Status
linux-4.19	INFO: rcu detected stall in garp_join_timer	7	385d	416d	0/1	auto-closed as invalid on 2020/06/07 13:30
upstream	INFO: rcu detected stall in garp_join_timer	1	456d	456d	0/21	closed as invalid on 2019/11/29 14:24
upstream	INFO: rcu detected stall in garp_join_timer (2)	14	27d	377d	0/21	upstream: reported on 2020/02/16 10:50
linux-4.19	INFO: rcu detected stall in garp_join_timer (2)	1	252d	252d	0/1	auto-closed as invalid on 2020/10/18 11:34
linux-4.19	INFO: rcu detected stall in garp_join_timer (3)	1	45d	45d	0/1	upstream: reported on 2021/01/13 13:34

Sample crash report:

INFO: rcu_preempt self-detected stall on CPU
	1-...: (10499 ticks this GP) idle=772/140000000000002/0 softirq=57942/57942 fqs=15 
	 (t=10500 jiffies g=15819 c=15818 q=460)
rcu_preempt kthread starved for 10469 jiffies! g15819 c15818 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_preempt     R  running task    29104     8      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3384
 schedule+0x92/0x1c0 kernel/sched/core.c:3428
 schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1746
 rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
NMI backtrace for cpu 1
CPU: 1 PID: 26410 Comm: syz-executor.4 Not tainted 4.14.170-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:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
 rcu_dump_cpu_stacks+0x186/0x1d2 kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x43d/0xd0a kernel/rcu/tree.c:2792
 update_process_times+0x31/0x70 kernel/time/timer.c:1590
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:165
 tick_sched_timer+0x43/0x130 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x270/0xbc0 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x95/0xe0 kernel/locking/spinlock.c:192
RSP: 0000:ffff8880aed07c20 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fe2ce1 RBX: 0000000000000286 RCX: 1ffff1100b8709a4
RDX: dffffc0000000000 RSI: ffff88805c384d00 RDI: 0000000000000286
RBP: ffff8880aed07c30 R08: ffff88805c384480 R09: ffff88805c384d20
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aed239c0
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8880aed239c0
 __mod_timer kernel/time/timer.c:1026 [inline]
 mod_timer+0x56c/0xeb0 kernel/time/timer.c:1069
 garp_join_timer_arm+0x5e/0x80 net/802/garp.c:401
 garp_join_timer+0x74/0x80 net/802/garp.c:414
 call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
 expire_timers kernel/time/timer.c:1318 [inline]
 __run_timers kernel/time/timer.c:1636 [inline]
 __run_timers kernel/time/timer.c:1604 [inline]
 run_timer_softirq+0x5b7/0x1520 kernel/time/timer.c:1649
 __do_softirq+0x244/0x9a0 kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x160/0x1b0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0033:0x403e0e
RSP: 002b:00007f225b747c90 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10
RAX: eff3cbf96ec6ef00 RBX: 000000000075bf28 RCX: 000000000045b3b9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000075bf20
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c
R13: 00000000000000b8 R14: 00007f225b7489c0 R15: 000000000075bf2c
INFO: rcu_sched detected stalls on CPUs/tasks:
	(detected by 0, t=10539 jiffies, g=12488, c=12487, q=21)
INFO: Stall ended before state dump start

Crashes (4):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report
ci2-linux-4-14	2020/02/13 11:12	linux-4.14.y	e0f8b8a6	84f4fc8a	.config	log	report
ci2-linux-4-14	2020/02/09 08:03	linux-4.14.y	e0f8b8a6	06150bf1	.config	log	report
ci2-linux-4-14	2020/02/05 05:00	linux-4.14.y	9fa690a2	93e5e335	.config	log	report
ci2-linux-4-14	2020/01/29 07:14	linux-4.14.y	9a95f252	c8e81ce4	.config	log	report