rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=c68c/1/0x4000000000000000 softirq=11980/11981 fqs=768
rcu: (t=10501 jiffies g=9869 q=1150 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 8963 jiffies! g9869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=6776
rcu: rcu_preempt kthread starved for 8966 jiffies! g9869 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:27752 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: 6152 Comm: syz-executor 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: 0000555585643500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f03987e6038 CR3: 000000005b42c000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 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:memory_is_nonzero mm/kasan/generic.c:101 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline]
RIP: 0010:kasan_check_range+0x67/0x290 mm/kasan/generic.c:187
Code: 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 <4d> 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c
RSP: 0018:ffffc900045df868 EFLAGS: 00000a07
RAX: ffffffff81c87901 RBX: dffffc0000000001 RCX: ffffffff81c879d4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001dd7740
RBP: ffff888024191c80 R08: ffffea0001dd7747 R09: 1ffffd40003baee8
R10: dffffc0000000000 R11: fffff940003baee8 R12: dffffc0000000000
R13: 1ffffd40003baee9 R14: fffff940003baee9 R15: 1ffffd40003baee8
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
PageSwapBacked include/linux/page-flags.h:515 [inline]
mm_counter_file+0xd4/0x2c0 include/linux/mm.h:2651
insert_page_into_pte_locked+0x15c/0x4b0 mm/memory.c:1841
insert_page mm/memory.c:1868 [inline]
vm_insert_page+0x560/0x8b0 mm/memory.c:2021
kcov_mmap+0xe9/0x160 kernel/kcov.c:505
call_mmap include/linux/fs.h:2023 [inline]
mmap_file mm/internal.h:98 [inline]
__mmap_region mm/mmap.c:2790 [inline]
mmap_region+0xfa5/0x2020 mm/mmap.c:2941
do_mmap+0x92f/0x10a0 mm/mmap.c:1385
vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556
ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431
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: 0033:0x7f039858f783
Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7
RSP: 002b:00007ffed5de7278 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f03987e6218 RCX: 00007f039858f783
RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f03977fb000
RBP: 00007f03987e6218 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000003 R14: 00007ffed5de7568 R15: 0000000000000000
CPU: 0 PID: 6129 Comm: syz.1.75 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:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x1f/0x80 kernel/kcov.c:293
Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d e0 22 7e 7e 65 8b 15 e1 22 7e 7e 81 e2 00 01 ff 00 74 11 <81> fa 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 4e 8b 91 f8 15 00
RSP: 0018:ffffc90000006ef0 EFLAGS: 00000206
RAX: ffffffff813aa7f8 RBX: ffffffff8ec2d31c RCX: ffff88801b2f0000
RDX: 0000000000000100 RSI: ffffffff8a672eb0 RDI: ffffffff8a672ebc
RBP: ffffffff8ec2d30c R08: ffffc90000007090 R09: 0000000000000023
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8ec2d310
R13: ffffffff8a672ebc R14: ffffffff8a672eb0 R15: ffffffff8ec2d314
FS: 00007fb637ef76c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001afee000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
unwind_next_frame+0x4b8/0x2970 arch/x86/kernel/unwind_orc.c:494
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x280 mm/slub.c:3852
skb_kfree_head net/core/skbuff.c:947 [inline]
skb_free_head net/core/skbuff.c:961 [inline]
skb_release_data+0x60a/0x800 net/core/skbuff.c:991
skb_release_all net/core/skbuff.c:1057 [inline]
__kfree_skb net/core/skbuff.c:1071 [inline]
consume_skb+0xb2/0x110 net/core/skbuff.c:1287
netlink_broadcast_filtered+0x101c/0x1110 net/netlink/af_netlink.c:1538
netlink_broadcast net/netlink/af_netlink.c:1560 [inline]
nlmsg_multicast include/net/netlink.h:1090 [inline]
nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2588
__neigh_notify+0x1ae/0x300 net/core/neighbour.c:3535
neigh_cleanup_and_release+0xa0/0x260 net/core/neighbour.c:102
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:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254
Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 80 ca 14 09 e8 4b a4 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000be17918 EFLAGS: 00000286
RAX: 3fa684aae23dc700 RBX: 0000000000000000 RCX: 3fa684aae23dc700
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffc9000be17970 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: ffff88801b2f0000
R13: dffffc0000000000 R14: ffff88802dd65a00 R15: ffff8880b8e3cac8
context_switch kernel/sched/core.c:5383 [inline]
__schedule+0x14da/0x44d0 kernel/sched/core.c:6699
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1068/0x1400 kernel/signal.c:2867
arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb636f8f749
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:00007fb637ef7038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000006 RBX: 00007fb6371e6090 RCX: 00007fb636f8f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007fb637013f91 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6371e6128 R14: 00007fb6371e6090 R15: 00007ffda5820188