rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4252/1:b..l P154/1:b..l
(detected by 1, t=10502 jiffies, g=10245, q=145)
task:kworker/u4:2 state:R running task stack:24424 pid: 154 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_irq+0xb1/0x150 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+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90001ef7aa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: da9d6abf95131000
RDX: 0000000000000000 RSI: ffffffff8a0b2ac0 RDI: ffffffff8a59a480
RBP: ffffc90001ef7bc0 R08: dffffc0000000000 R09: fffffbfff1ff7819
R10: fffffbfff1ff7819 R11: 1ffffffff1ff7818 R12: ffffffff8c11c660
R13: 1ffff920003def60 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
rcu_read_lock include/linux/rcupdate.h:739 [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+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
task:kworker/u4:5 state:R running task stack:21352 pid: 4252 ppid: 2 flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6650
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
trace_kmalloc include/trace/events/kmem.h:46 [inline]
kmem_cache_alloc_trace+0x132/0x2a0 mm/slub.c:3251
kmalloc include/linux/slab.h:604 [inline]
kzalloc include/linux/slab.h:735 [inline]
sctp_inet6addr_event+0x37b/0x730 net/sctp/ipv6.c:86
notifier_call_chain kernel/notifier.c:83 [inline]
atomic_notifier_call_chain+0x15d/0x280 kernel/notifier.c:198
ipv6_add_addr+0xb30/0xde0 net/ipv6/addrconf.c:1182
addrconf_add_linklocal+0x280/0x6b0 net/ipv6/addrconf.c:3238
addrconf_addr_gen+0x4ee/0x620 net/ipv6/addrconf.c:3369
addrconf_init_auto_addrs+0x6d5/0xa80 net/ipv6/addrconf.c:-1
addrconf_notify+0xa6b/0xf00 net/ipv6/addrconf.c:3662
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
netdev_state_change+0xd2/0x140 net/core/dev.c:1440
linkwatch_do_dev+0x10d/0x160 net/core/link_watch.c:167
__linkwatch_run_queue+0x4a9/0x7b0 net/core/link_watch.c:213
linkwatch_event+0x48/0x50 net/core/link_watch.c:252
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
process_scheduled_works kernel/workqueue.c:2373 [inline]
worker_thread+0xdca/0x12a0 kernel/workqueue.c:2459
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10567 jiffies! g10245 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27008 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 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 1
CPU: 1 PID: 4519 Comm: syz.3.20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 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+0x10c8/0x1220 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+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
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:1690 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
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:__sanitizer_cov_trace_cmp8+0x0/0x80 kernel/kcov.c:273
Code: 28 4d 39 ca 77 22 89 ff 89 f6 4a c7 44 02 08 04 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 <48> 8b 04 24 65 48 8b 0d b4 a2 8a 7e 65 8b 15 b5 a2 8a 7e 81 e2 00
RSP: 0018:ffffc90003b5fc60 EFLAGS: 00000293
RAX: ffffffff83dadaf3 RBX: 0000000000000030 RCX: ffff888070c98000
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 00007ffdcd889360
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad323e
R10: fffffbfff1ad323e R11: 1ffffffff1ad323d R12: ffffc90003b5fde0
R13: 00007ffdcd889360 R14: ffffc90003b5fe00 R15: 00007ffdcd889330
__chk_range_not_ok arch/x86/include/asm/uaccess.h:33 [inline]
_copy_to_user+0xb2/0x130 lib/usercopy.c:38
copy_to_user include/linux/uaccess.h:200 [inline]
copy_siginfo_to_user+0x20/0x80 kernel/signal.c:3367
__setup_rt_frame arch/x86/kernel/signal.c:490 [inline]
setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
handle_signal arch/x86/kernel/signal.c:824 [inline]
arch_do_signal_or_restart+0xd56/0x1300 arch/x86/kernel/signal.c:869
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: 0033:0x7fa311a92880
Code: 00 0f 85 f3 fc ff ff c3 66 90 0f b7 07 0f b7 0e 0f c8 0f c9 d1 e8 d1 e9 0f b6 7c 17 ff 0f b6 74 16 ff 09 f8 09 f1 29 c8 c3 90 <48> 83 fa 20 0f 82 d6 02 00 00 c5 fe 6f 0e c5 f5 74 0f c5 fd d7 c1
RSP: 002b:00007ffdcd8897a8 EFLAGS: 00000246
RAX: 000000000000000e RBX: 00007fa312852720 RCX: 000000000000002e
RDX: 0000000000000006 RSI: 0000001b31263fd2 RDI: 0000001b31263ff2
RBP: 0000001b31263fd2 R08: 000000000003fde8 R09: 0000000000000000
R10: 0000001b31224218 R11: 0000000000000006 R12: 0000000000000028
R13: 000000000000000e R14: 0000001b31224220 R15: 0000001b31224218
sched: RT throttling activated