INFO: rcu detected stall in batadv_nc

INFO: rcu detected stall in batadv_nc_worker (3)
Status: upstream: reported on 2020/10/01 10:35
Reported-by: syzbot+69904c3b4a09e8fa2e1b@syzkaller.appspotmail.com
First crash: 346d, last: 14d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	INFO: rcu detected stall in batadv_nc_worker				7	504d	505d	0/22	closed as invalid on 2019/12/04 14:04
upstream	INFO: rcu detected stall in batadv_nc_worker (2)				4	469d	469d	0/22	closed as invalid on 2020/01/09 08:13

Sample crash report:

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P25/1:b..l
	(detected by 1, t=10502 jiffies, g=61033, q=55)
task:kworker/u4:2    state:R  running task     stack:24336 pid:   44 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 context_switch kernel/sched/core.c:4329 [inline]
 __schedule+0x911/0x2160 kernel/sched/core.c:5079
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5536
 irqentry_exit_cond_resched kernel/entry/common.c:392 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:384 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:lock_acquire+0x1ef/0x740 kernel/locking/lockdep.c:5480
Code: 27 a8 7e 83 f8 01 0f 85 ee 03 00 00 9c 58 f6 c4 02 0f 85 d9 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90000e8fba0 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920001d1f76 RCX: 000000006e3715c0
RDX: 1ffff110023db13e RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fafd8a7
R10: fffffbfff1f5fb14 R11: 0000000000000000 R12: 0000000000000002
R13: ffffffff8bf75220 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:657 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline]
 batadv_nc_worker+0x12d/0xe50 net/batman-adv/network-coding.c:715
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
task:kworker/u4:1    state:R  running task     stack:24928 pid:   25 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:4329 [inline]
 __schedule+0x911/0x2160 kernel/sched/core.c:5079
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5536
 irqentry_exit_cond_resched kernel/entry/common.c:392 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:384 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:lock_acquire+0x1ef/0x740 kernel/locking/lockdep.c:5480
Code: 27 a8 7e 83 f8 01 0f 85 ee 03 00 00 9c 58 f6 c4 02 0f 85 d9 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc90000dffa58 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920001bff4d RCX: 0000000027c65334
RDX: 1ffff1100239485e RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fafd8a7
R10: fffffbfff1f5fb14 R11: 0000000000000000 R12: 0000000000000002
R13: ffffffff8bf75220 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:657 [inline]
 inet_twsk_purge+0x117/0x7c0 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:178
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g61033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=33251
rcu: rcu_preempt kthread starved for 10502 jiffies! g61033 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:
task:rcu_preempt     state:I stack:28904 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4329 [inline]
 __schedule+0x911/0x2160 kernel/sched/core.c:5079
 schedule+0xcf/0x270 kernel/sched/core.c:5158
 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1878
 rcu_gp_fqs_loop kernel/rcu/tree.c:1983 [inline]
 rcu_gp_kthread+0xd07/0x2300 kernel/rcu/tree.c:2156
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1 Comm: systemd Not tainted 5.12.0-rc6-next-20210407-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1194 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x21/0x150 kernel/rcu/tree.c:1186
Code: 84 00 00 00 00 00 0f 1f 00 65 8b 15 59 b8 a1 7e 81 e2 00 00 f0 00 b8 01 00 00 00 75 0a 8b 15 3e a1 67 0c 85 d2 75 01 c3 55 53 <65> ff 05 38 b8 a1 7e e8 93 5b ae 07 48 c7 c3 40 61 03 00 83 f8 07
RSP: 0000:ffffc90000c67c50 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 1ffff9200018cf91 RCX: ffffffff8159d1e8
RDX: 0000000000000001 RSI: 0000000000010003 RDI: ffff8880b9c36288
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8dc7d7cf
R10: fffffbfff1b8faf9 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880b9c26398 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fed584f6500(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556d339fd058 CR3: 0000000024955000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
 rcu_read_lock_held_common kernel/rcu/update.c:102 [inline]
 rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x5e9/0x740 kernel/locking/lockdep.c:5483
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:167
 __run_hrtimer kernel/time/hrtimer.c:1541 [inline]
 __hrtimer_run_queues+0x243/0xe40 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0033:0x7fed56a5d681
Code: 00 4c 29 e0 31 c9 4b 8d 34 26 49 39 d7 4c 89 e2 0f 95 c1 48 83 ca 01 48 83 c8 01 48 c1 e1 02 49 89 77 58 48 09 ca 49 89 56 08 <48> 89 46 08 e9 1a f9 ff ff 48 8d 0d 4f d4 0e 00 48 8d 35 ef 93 0e
RSP: 002b:00007ffef4b74ae0 EFLAGS: 00010202
RAX: 000000000001dfb1 RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000000a1 RSI: 0000556d339fd050 RDI: 0000000000000004
RBP: 0000000000002710 R08: 0000000000000003 R09: 00000000000000a0
R10: cb92ca33b4b9f458 R11: aa93d3cad1cf7c00 R12: 00000000000000a0
R13: 00007fed56d7db58 R14: 0000556d339fcfb0 R15: 00007fed56d7db00

Crashes (13):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci-upstream-linux-next-kasan-gce-root	2021/04/07 15:24	linux-next	5103a5be	6a81331a	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-root	2020/12/31 16:10	upstream	f6e1ea19	79264ae3	.config	log	report	info
ci-upstream-kasan-gce-root	2020/10/09 00:16	upstream	3d006ee4	92390980	.config	log	report	info
ci-upstream-kasan-gce-smack-root	2020/08/06 00:31	upstream	fffe3ae0	0487ea6f	.config	log	report
ci-upstream-kasan-gce-root	2020/07/08 03:46	upstream	7cc2a8ea	51095195	.config	log	report
ci-upstream-kasan-gce-smack-root	2020/07/07 14:37	upstream	7cc2a8ea	51095195	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/05/30 22:53	upstream	ffeb595d	6f3e1c7c	.config	log	report
ci-upstream-kasan-gce-root	2020/05/10 07:00	upstream	1d3962ae	8742a2b9	.config	log	report
ci-upstream-kasan-gce-386	2020/07/13 03:50	upstream	4437dd6e	9ebcc5b1	.config	log	report
ci-upstream-net-this-kasan-gce	2020/07/22 15:39	net	2c4dc314	128cd85f	.config	log	report
ci-upstream-net-this-kasan-gce	2020/07/03 01:55	net	e4b9a72d	bed10395	.config	log	report
ci-upstream-net-kasan-gce	2020/09/01 04:44	net-next	c30a3c95	d5a3ae1f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/02 03:53	linux-next	b36c9697	abf9ba4f	.config	log	report