rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=5fdc/1/0x4000000000000000 softirq=17612/17634 fqs=0
rcu: (detected by 0, t=10503 jiffies, g=17229, q=609 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5828 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: mld mld_ifc_work
RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:2090 [inline]
RIP: 0010:__hrtimer_run_queues+0x4c5/0xa10 kernel/time/hrtimer.c:2131
Code: 80 3b 01 75 18 e8 db 9e 13 00 eb 27 e8 d4 9e 13 00 49 bd 00 00 00 00 00 fc ff df eb 16 e8 c3 9e 13 00 48 89 ef 48 8b 74 24 38 <31> d2 31 c9 e8 a2 35 00 00 43 0f b6 04 2f 84 c0 48 8b 14 24 0f 85
RSP: 0018:ffffc90000a17c58 EFLAGS: 00000002
RAX: ffffffff81b44f4d RBX: ffff88802f406338 RCX: ffff88807f9f1f40
RDX: 0000000001000101 RSI: ffff8880b8728440 RDI: ffff88802f406300
RBP: ffff88802f406300 R08: 0000000001000101 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000142f7c R12: ffff8880b8728280
R13: dffffc0000000000 R14: ffff8880b87284a0 R15: 1ffff110170e508a
FS: 0000000000000000(0000) GS:ffff888124dc7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff03bfd3708 CR3: 000000007eae2000 CR4: 00000000003526f0
Call Trace:
hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2250
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:6021
Code: 1b 00 00 b8 ff ff ff ff 65 0f c1 05 1c ec ae 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 5b 01 03 00 cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc90000a17f58 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 8000000000000101
RDX: 8000000000000100 RSI: ffffffff8e69f504 RDI: ffffffff8c6dad80
RBP: 00000000ffffffff R08: 0000000000000100 R09: 0000000000000000
R10: 000000000000000a R11: ffffffff8ac042d0 R12: 0000000000000246
R13: ffff88807f9f1f40 R14: ffffffff8ed5c8a0 R15: 0000000000000003
net_generic+0x101/0x240 include/net/netns/generic.h:46
is_vlan_arp net/bridge/br_netfilter_hooks.c:110 [inline]
br_nf_forward_finish+0x1ad/0xea0 net/bridge/br_netfilter_hooks.c:644
NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:325
br_nf_forward_ip+0x7e7/0xa30 net/bridge/br_netfilter_hooks.c:721
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:323
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
br_handle_frame_finish+0x1119/0x1950 net/bridge/br_input.c:229
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:325 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x1329/0x1600 net/bridge/br_input.c:451
__netif_receive_skb_core+0x989/0x30c0 net/core/dev.c:6184
__netif_receive_skb_one_core net/core/dev.c:6295 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x727/0x18b0 net/core/dev.c:6761
__napi_poll+0xaa/0x330 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8050
handle_softirqs+0x226/0x860 kernel/softirq.c:645
do_softirq+0x77/0xd0 kernel/softirq.c:546
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:923 [inline]
__dev_queue_xmit+0x1efb/0x3920 net/core/dev.c:4993
NF_HOOK_COND include/linux/netfilter.h:314 [inline]
ip6_output+0x337/0x540 net/ipv6/ip6_output.c:248
dst_output include/net/dst.h:472 [inline]
NF_HOOK+0x177/0x4f0 include/linux/netfilter.h:325
mld_sendpack+0x890/0xe10 net/ipv6/mcast.c:1890
mld_send_cr net/ipv6/mcast.c:2191 [inline]
mld_ifc_work+0x842/0xd60 net/ipv6/mcast.c:2739
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10503 jiffies! g17229 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27656 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5734 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:csd_lock_wait kernel/smp.c:363 [inline]
RIP: 0010:csd_lock kernel/smp.c:396 [inline]
RIP: 0010:smp_call_function_many_cond+0x61e/0x1500 kernel/smp.c:944
Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 01 59 0c 00 41 83 e7 01 75 07 e8 f6 53 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01
RSP: 0000:ffffc90003d2f320 EFLAGS: 00000293
RAX: ffffffff81bb9a3e RBX: ffff8880b87414c8 RCX: ffff888029098000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003d2f470 R08: ffff88802909959f R09: 1ffff110052132b3
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff110170e8299
R13: 0000000000000001 R14: ffff8880b87414c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124cc7000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00005654e93ffa38 CR3: 000000006fa94000 CR4: 00000000003526f0
Call Trace:
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x8ff/0x1090 arch/x86/mm/tlb.c:1435
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549
free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline]
exit_mmap+0x1bf/0x9f0 mm/mmap.c:1300
__mmput+0x118/0x420 kernel/fork.c:1193
exit_mm+0x18e/0x240 kernel/exit.c:592
do_exit+0x6cd/0x2360 kernel/exit.c:974
do_group_exit+0x22d/0x2f0 kernel/exit.c:1129
get_signal+0x121b/0x12c0 kernel/signal.c:3112
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_int80_emulation+0x314/0x500 arch/x86/entry/syscall_32.c:169
asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71875ab
Code: Unable to access opcode bytes at 0xf7187581.
RSP: 002b:00000000ffe2740c EFLAGS: 00000246 ORIG_RAX: 0000000000000072
RAX: fffffffffffffe00 RBX: 00000000ffffffff RCX: 00000000ffe2754c
RDX: 0000000040000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000