rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1232/1:b..l P4365/1:b..l
(detected by 0, t=10502 jiffies, g=32421, q=22)
task:kworker/u4:11 state:R running task stack:23152 pid: 4365 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc9000388faa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: e12d87e963a20700
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4200
RBP: ffffc9000388fbc0 R08: dffffc0000000000 R09: 1ffffffff203dc18
R10: dffffc0000000000 R11: fffffbfff203dc19 R12: ffffffff8c31ef60
R13: 1ffff92000711f60 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0xc9/0x5c0 net/batman-adv/network-coding.c:723
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
task:kworker/u4:4 state:R running task stack:22096 pid: 1232 ppid: 2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:206
Code: 48 8b 3d a0 0e 12 0c 48 89 de 5b e9 47 5a 44 00 00 00 cc cc 00 00 cc 48 8b 04 24 65 48 8b 0d 34 6e 89 7e 65 8b 15 35 6e 89 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00
RSP: 0018:ffffc90004fd7a58 EFLAGS: 00000202
RAX: ffffffff88678da3 RBX: 0000000000000001 RCX: ffff888022f21dc0
RDX: 0000000080000000 RSI: ffffffff8a7a41e0 RDI: ffffffff8a7a41a0
RBP: ffffc90004fd7b50 R08: dffffc0000000000 R09: 1ffffffff203dc18
R10: dffffc0000000000 R11: fffffbfff203dc19 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000000590a1 R15: ffffffff8d628940
rcu_read_unlock include/linux/rcupdate.h:769 [inline]
inet_twsk_purge+0x713/0x820 net/ipv4/inet_timewait_sock.c:309
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x78e/0xba0 net/core/net_namespace.c:635
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10502 jiffies! g32421 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:27440 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 8739 Comm: syz.8.931 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x845/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 7e d3 93 f7 48 89 df e8 b6 aa 94 f7 e8 01 a0 b5 f7 fb bf 01 00 00 00 96 c0 88 f7 65 8b 05 07 e8 38 76 85 c0 74 02 5b c3 e8 44 f5 36
RSP: 0018:ffffc900035afbc0 EFLAGS: 00000282
RAX: 001577a96bf4ef00 RBX: ffff88802ae7dc80 RCX: 001577a96bf4ef00
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff88802ae7dc83 R09: 1ffff110055cfb90
R10: dffffc0000000000 R11: ffffed10055cfb91 R12: dffffc0000000000
R13: ffff88802ae7dc80 R14: 0000000000000021 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11f2/0x12e0 kernel/signal.c:2904
arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7db95e4e97
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f7db783d028 EFLAGS: 00000246
RAX: 000000000000012b RBX: 00007f7db986cfa0 RCX: 00007f7db95e4e99
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f7db967aeaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7db986d038 R14: 00007f7db986cfa0 R15: 00007ffeb79917c8