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: 527d, last: 23h29m

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	684d	686d	0/22	closed as invalid on 2019/12/04 14:04
upstream	INFO: rcu detected stall in batadv_nc_worker (2)				4	649d	650d	0/22	closed as invalid on 2020/01/09 08:13

Sample crash report:

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=dd7/1/0x4000000000000000 softirq=104137/104138 fqs=2513 
	(detected by 0, t=10502 jiffies, g=202181, q=1404)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 24541 Comm: kworker/u4:4 Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_acquire+0x3c/0x510 kernel/locking/lockdep.c:5593
Code: 89 fe 41 55 41 89 d5 41 54 41 89 cc 55 44 89 c5 53 48 81 ec b0 00 00 00 48 8d 5c 24 10 4c 89 0c 24 48 c7 44 24 10 b3 8a b5 41 <48> c1 eb 03 48 c7 44 24 18 aa 62 14 8b 48 01 d8 48 c7 44 24 20 70
RSP: 0018:ffffc90000fd8ce0 EFLAGS: 00000082
RAX: dffffc0000000000 RBX: ffffc90000fd8cf0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8b97f0a0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffed10123ffb5d R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8b97f0a0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f120f7541b8 CR3: 000000002a7be000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:687 [inline]
 advance_sched+0x4a5/0x9a0 net/sched/sch_taprio.c:763
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593
Code: 96 a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 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:ffffc9000bdbfba0 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920017b7f76 RCX: 0bf81aee8f9736ba
RDX: 1ffff11005f4154b RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fd059e7
R10: fffffbfff1fa0b3c R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8b97f0a0 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:687 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:410 [inline]
 batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:721
 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: rcu_preempt kthread starved for 5407 jiffies! g202181 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:28472 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb44/0x5960 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 6576 Comm: syz-executor.3 Not tainted 5.15.0-rc5-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:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481
 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:729 [inline]
 rcu_pending kernel/rcu/tree.c:3880 [inline]
 rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2599
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x6b/0x70 kernel/kcov.c:286
Code: 00 00 00 48 39 fe 72 22 44 89 c6 48 83 c2 01 48 89 4c 38 f0 48 c7 44 38 e0 05 00 00 00 48 89 74 38 e8 4e 89 54 c8 20 48 89 10 <c3> 0f 1f 40 00 41 57 41 56 49 89 d6 41 55 41 54 55 48 89 fd 53 48
RSP: 0018:ffffc9000409f8c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880b9d37180 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffff88807c71a080 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff816ac2e6 R11: 0000000000000000 R12: ffffed10173a6e31
R13: 0000000000000001 R14: ffff8880b9d37188 R15: 0000000000000001
 csd_lock_wait kernel/smp.c:440 [inline]
 smp_call_function_many_cond+0x476/0xc20 kernel/smp.c:969
 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:927 [inline]
 flush_tlb_mm_range+0x1d8/0x230 arch/x86/mm/tlb.c:1013
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:426 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:416 [inline]
 tlb_flush_mmu mm/mmu_gather.c:248 [inline]
 tlb_finish_mmu+0x3e7/0x8c0 mm/mmu_gather.c:340
 exit_mmap+0x1ea/0x630 mm/mmap.c:3173
 __mmput+0x122/0x4b0 kernel/fork.c:1115
 mmput+0x58/0x60 kernel/fork.c:1136
 exit_mm kernel/exit.c:501 [inline]
 do_exit+0xabc/0x2a30 kernel/exit.c:812
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2868
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f203b7c3761
Code: Unable to access opcode bytes at RIP 0x7f203b7c3737.
RSP: 002b:00007ffc3b104ae0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 0000000000000a9c RCX: 00007f203b7c3761
RDX: 00007ffc3b104b20 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc3b104bac R08: 0000000000000000 R09: 00007ffc3b11c080
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 000000000015a2eb R14: 0000000000000004 R15: 00007ffc3b104c10
----------------
Code disassembly (best guess):
   0:	89 fe                	mov    %edi,%esi
   2:	41 55                	push   %r13
   4:	41 89 d5             	mov    %edx,%r13d
   7:	41 54                	push   %r12
   9:	41 89 cc             	mov    %ecx,%r12d
   c:	55                   	push   %rbp
   d:	44 89 c5             	mov    %r8d,%ebp
  10:	53                   	push   %rbx
  11:	48 81 ec b0 00 00 00 	sub    $0xb0,%rsp
  18:	48 8d 5c 24 10       	lea    0x10(%rsp),%rbx
  1d:	4c 89 0c 24          	mov    %r9,(%rsp)
  21:	48 c7 44 24 10 b3 8a 	movq   $0x41b58ab3,0x10(%rsp)
  28:	b5 41
* 2a:	48 c1 eb 03          	shr    $0x3,%rbx <-- trapping instruction
  2e:	48 c7 44 24 18 aa 62 	movq   $0xffffffff8b1462aa,0x18(%rsp)
  35:	14 8b
  37:	48 01 d8             	add    %rbx,%rax
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	44 24 20             	rex.R and $0x20,%al
  3f:	70                   	.byte 0x70

Crashes (43):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci-upstream-kasan-gce-selinux-root	2021/10/18 09:16	upstream	cf52ad5ff16c	0c5d9412	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/10/16 21:46	upstream	304040fb4909	0c5d9412	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-root	2021/10/15 12:08	upstream	ec681c53f8d2	0c5d9412	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/10/14 17:11	upstream	26d657410983	5462d470	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/10/13 22:47	upstream	348949d9a444	5462d470	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/10/13 20:43	upstream	348949d9a444	5462d470	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/10/10 00:52	upstream	7fd2bf83d59a	838e7e2c	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/10/08 21:06	upstream	741668ef7832	efe0f24d	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/10/07 02:45	upstream	5af4055fa813	62ee0987	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/10/05 04:48	upstream	84b3e42564ac	ce697b49	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/10/04 07:58	upstream	9e1ff307c779	ce697b49	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/10/04 00:36	upstream	9e1ff307c779	db0f5787	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-root	2021/09/26 01:59	upstream	a5e0aceabef6	8cac236e	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-selinux-root	2021/09/24 19:30	upstream	4c4f0c2bf341	8cac236e	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/09/17 12:25	upstream	bdb575f87217	5b989942	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/08/19 17:52	upstream	d6d09a694205	b599f2fc	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-root	2021/08/12 12:04	upstream	1746f4db5135	6972b106	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-smack-root	2021/06/20 08:30	upstream	913ec3c22ef4	aba2b2fb	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-root	2021/05/12 21:56	upstream	dbb5afad100a	da958a4d	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-kasan-gce	2021/06/29 17:22	bpf	d6765985a42a	9d2ab5df	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-next-kasan-gce	2021/09/20 23:34	bpf-next	e57f52b42d1f	af796c18	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-next-kasan-gce	2021/08/31 16:32	bpf-next	a16ef91aa61a	8f58a0ef	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-next-kasan-gce	2021/08/24 22:50	bpf-next	a6258837c8a8	b599f2fc	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-next-kasan-gce	2021/08/12 07:29	bpf-next	25dc3895baaa	6972b106	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-next-kasan-gce	2021/06/09 00:28	bpf-next	380afe720896	5c2fe346	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-bpf-next-kasan-gce	2021/05/25 13:44	bpf-next	8fb33b605530	3c7fef33	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-linux-next-kasan-gce-root	2021/09/14 17:33	linux-next	815c5020b5ab	07e953c1	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-linux-next-kasan-gce-root	2021/09/13 03:28	linux-next	24a36d3171e4	5ae8508a	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-linux-next-kasan-gce-root	2021/08/29 12:22	linux-next	5e63226c7228	be2c130d	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-linux-next-kasan-gce-root	2021/08/28 12:27	linux-next	5e63226c7228	be2c130d	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-linux-next-kasan-gce-root	2021/04/07 15:24	linux-next	5103a5be098c	6a81331a	.config	log	report	info	INFO: rcu detected stall in batadv_nc_worker
ci-upstream-kasan-gce-root	2020/12/31 16:10	upstream	f6e1ea196492	79264ae3	.config	log	report	info
ci-upstream-kasan-gce-root	2020/10/09 00:16	upstream	3d006ee42dde	92390980	.config	log	report	info
ci-upstream-kasan-gce-smack-root	2020/08/06 00:31	upstream	fffe3ae0ee84	0487ea6f	.config	log	report
ci-upstream-kasan-gce-root	2020/07/08 03:46	upstream	7cc2a8ea1048	51095195	.config	log	report
ci-upstream-kasan-gce-smack-root	2020/07/07 14:37	upstream	7cc2a8ea1048	51095195	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/05/30 22:53	upstream	ffeb595d8481	6f3e1c7c	.config	log	report
ci-upstream-kasan-gce-root	2020/05/10 07:00	upstream	1d3962ae3b3d	8742a2b9	.config	log	report
ci-upstream-kasan-gce-386	2020/07/13 03:50	upstream	4437dd6e8f71	9ebcc5b1	.config	log	report
ci-upstream-net-this-kasan-gce	2020/07/22 15:39	net	2c4dc3148603	128cd85f	.config	log	report
ci-upstream-net-this-kasan-gce	2020/07/03 01:55	net	e4b9a72d76a4	bed10395	.config	log	report
ci-upstream-net-kasan-gce	2020/09/01 04:44	net-next	c30a3c957c88	d5a3ae1f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/02 03:53	linux-next	b36c969764ab	abf9ba4f	.config	log	report