rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (1 GPs behind) idle=9eb4/1/0x4000000000000000 softirq=27264/27265 fqs=5092
rcu: hardirqs softirqs csw/system
rcu: number: 1206441 0 0
rcu: cputime: 18207 34271 40 ==> 52510(ms)
rcu: (t=10503 jiffies g=31345 q=2258 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 277 jiffies! g31345 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=30138
rcu: rcu_preempt kthread starved for 280 jiffies! g31345 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27088 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:queued_write_lock_slowpath+0x125/0x294 kernel/locking/qrwlock.c:85
Code: f0 41 81 0e 00 01 00 00 42 0f b6 04 23 84 c0 74 37 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 2a 4c 89 f7 e8 bf be 6b f7 eb 20 f3 90 <42> 0f b6 04 23 84 c0 74 15 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 08
RSP: 0018:ffffc900001f0520 EFLAGS: 00000206
RAX: 00000000000001ff RBX: 1ffffffff1c19108 RCX: ffffffff8a713fab
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e0c8840
RBP: ffffc900001f05d0 R08: ffffffff8e0c8843 R09: 1ffffffff1c19108
R10: dffffc0000000000 R11: fffffbfff1c19109 R12: dffffc0000000000
R13: 1ffff9200003e0a8 R14: ffffffff8e0c8840 R15: ffffc900001f0570
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055582151ea38 CR3: 000000000cb30000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
queued_write_lock include/asm-generic/qrwlock.h:101 [inline]
do_raw_write_lock+0x1ee/0x260 kernel/locking/spinlock_debug.c:210
neigh_forced_gc net/core/neighbour.c:265 [inline]
neigh_alloc net/core/neighbour.c:486 [inline]
___neigh_create+0x20f/0x2440 net/core/neighbour.c:649
ip6_finish_output2+0x159e/0x1650 net/ipv6/ip6_output.c:132
dst_output include/net/dst.h:467 [inline]
NF_HOOK include/linux/netfilter.h:304 [inline]
ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513
addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2
RAX: 8570bb41a2ac6100 RBX: ffffffff8161881b RCX: 8570bb41a2ac6100
RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65
R10: dffffc0000000000 R11: ffffed10171e6d66 R12: ffffffff8e4a2128
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110037ca780
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:170 [inline]
do_idle+0x1eb/0x510 kernel/sched/idle.c:282
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b
CPU: 0 PID: 8645 Comm: syz.9.742 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x2e/0x60 kernel/kcov.c:216
Code: 48 8b 04 24 65 48 8b 0d f0 24 7e 7e 65 8b 15 f1 24 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 <74> 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b
RSP: 0018:ffffc90000007110 EFLAGS: 00000246
RAX: ffffffff813ac064 RBX: 0000000000000302 RCX: ffff88802d949e00
RDX: 0000000000000100 RSI: 0000000000000302 RDI: 0000000000000000
RBP: ffffc90000007668 R08: ffff88802d949e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900000071e8
R13: dffffc0000000000 R14: ffffc900000076a8 R15: ffffc900000071f8
FS: 00007ff11ecc86c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000001 CR3: 000000006165e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
unwind_next_frame+0x1d24/0x2970 arch/x86/kernel/unwind_orc.c:672
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452
neigh_del net/core/neighbour.c:226 [inline]
neigh_remove_one+0x5f1/0x700 net/core/neighbour.c:247
neigh_forced_gc net/core/neighbour.c:280 [inline]
neigh_alloc net/core/neighbour.c:486 [inline]
___neigh_create+0x467/0x2440 net/core/neighbour.c:649
ip6_finish_output2+0x159e/0x1650 net/ipv6/ip6_output.c:132
dst_output include/net/dst.h:467 [inline]
NF_HOOK include/linux/netfilter.h:304 [inline]
ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513
addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006
call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x52d/0x7d0 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:generic_exec_single+0x476/0x4f0 kernel/smp.c:418
Code: 75 11 e8 cd e6 0a 00 48 85 db 75 16 e8 c3 e6 0a 00 eb 15 e8 bc e6 0a 00 e8 47 cd ec 08 48 85 db 74 ea e8 ad e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c
RSP: 0018:ffffc9000de4fa00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc9000fb51000 RSI: 0000000000002a6b RDI: 0000000000002a6c
RBP: ffffc9000de4fad0 R08: ffffffff90d945ff R09: 1ffffffff21b28bf
R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: 1ffff92001bc9f44
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92001bc9f65
smp_call_function_single+0x352/0x580 kernel/smp.c:647
task_function_call kernel/events/core.c:120 [inline]
perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948
__do_sys_perf_event_open kernel/events/core.c:12915 [inline]
__se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12567
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff11dd8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff11ecc8038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007ff11dfe6090 RCX: 00007ff11dd8f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007ff11de13f91 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff11dfe6128 R14: 00007ff11dfe6090 R15: 00007ffe37ef8978