bridge0: port 1(bridge_slave_0) entered forwarding state
bridge0: topology change detected, propagating
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: topology change detected, propagating
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13885/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=288665, q=85033 ncpus=2)
task:syz.6.8715 state:R running task stack:25352 pid:13885 tgid:13882 ppid:10125 task_flags:0x40054c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x484/0x2550 arch/x86/kernel/unwind_orc.c:520
Code: d2 84 c0 48 0f 45 d1 48 89 15 c8 9b c8 11 48 85 d2 0f 84 3b 02 00 00 4c 8d 62 04 4c 8d 6a 05 4c 89 e0 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 c2 19 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f
RSP: 0018:ffffc90004f46af8 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffffffff90493988 RCX: ffffffff9049398c
RDX: ffffffff90c5018e RSI: ffffffff90c5015e RDI: ffffffff8c28af00
RBP: dffffc0000000000 R08: 0000000000000009 R09: ffffffff8e95cd60
R10: ffffc90004f46c28 R11: fffff520009e8d91 R12: ffffffff90c50192
R13: ffffffff90c50193 R14: ffffc90004f46c28 R15: ffffffff90493988
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xcec/0x1480 mm/page_alloc.c:3004
folios_put_refs+0x9ff/0xb40 mm/swap.c:1008
free_pages_and_swap_cache+0x2b9/0x490 mm/swap_state.c:401
__tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:424
zap_pte_range mm/memory.c:1957 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x3dc3/0x4b40 mm/memory.c:2093
unmap_vmas+0x379/0x530 mm/memory.c:2162
exit_mmap+0x280/0x9e0 mm/mmap.c:1300
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x18e/0x250 kernel/exit.c:581
do_exit+0x6a2/0x22c0 kernel/exit.c:963
do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98
__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:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c5479cdd9
RSP: 002b:00007f9c556040e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f9c54a16188 RCX: 00007f9c5479cdd9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9c54a16188
RBP: 00007f9c54a16180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c54a16218 R14: 00007f9c54b3f960 R15: 00007f9c54b3fa48
rcu: rcu_preempt kthread starved for 252 jiffies! g288665 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 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: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320
Code: 11 10 48 89 74 11 18 48 89 44 11 20 e9 09 f2 e5 09 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 48 69 73 11 65 8b 15 69 69 73
RSP: 0018:ffffc90000a07040 EFLAGS: 00000246
RAX: ffffffff897cf4e6 RBX: 0000000000000001 RCX: 0000000000000100
RDX: ffff88801de98000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000081 R08: ffff88801de98000 R09: 0000000000000002
R10: 0000000000004888 R11: 0000000000000100 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88809edfcc80 R15: ffff88809edfcd01
FS: 0000000000000000(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f42d3f3eccc CR3: 0000000034020000 CR4: 00000000003526f0
Call Trace:
validate_xmit_skb+0x157/0x14a0 net/core/dev.c:-1
__dev_queue_xmit+0xb2f/0x3950 net/core/dev.c:4860
dev_queue_xmit include/linux/netdevice.h:3418 [inline]
vlan_dev_hard_start_xmit+0x204/0x430 net/8021q/vlan_dev.c:126
__netdev_start_xmit include/linux/netdevice.h:5368 [inline]
netdev_start_xmit include/linux/netdevice.h:5377 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870
dev_queue_xmit include/linux/netdevice.h:3418 [inline]
br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53
NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318
br_nf_post_routing+0xb66/0xfe0 net/bridge/br_netfilter_hooks.c:960
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1161 [inline]
br_nf_forward_finish+0xa5e/0xe90 net/bridge/br_netfilter_hooks.c:663
NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318
br_nf_forward_ip+0x7ef/0xa30 net/bridge/br_netfilter_hooks.c:717
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238
br_handle_frame_finish+0x1521/0x1c80 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+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x1277/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6089
__netif_receive_skb_list_core+0x24d/0x810 net/core/dev.c:6277
__netif_receive_skb_list net/core/dev.c:6344 [inline]
netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6435
gro_normal_list include/net/gro.h:523 [inline]
gro_flush_normal include/net/gro.h:531 [inline]
napi_complete_done+0x299/0x730 net/core/dev.c:6803
gro_cell_poll+0x5a9/0x5d0 net/core/gro_cells.c:74
__napi_poll+0xae/0x340 net/core/dev.c:7730
napi_poll net/core/dev.c:7793 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7950
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 9b 7d 02 e9 93 f7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 a1 20 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000246
RAX: 000000000229e9d1 RBX: ffffffff819a93ba RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dfa6837 RDI: ffffffff8c28af60
RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b
R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001
R13: 1ffff11003bd3000 R14: 0000000000000001 R15: 1ffff11003bd3000
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147