rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (1 GPs behind) idle=ad14/1/0x4000000000000000 softirq=41074/41075 fqs=2645
rcu: hardirqs softirqs csw/system
rcu: number: 1316251 0 0
rcu: cputime: 16516 34238 64 ==> 50760(ms)
rcu: (t=10500 jiffies g=54917 q=3279 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 448 jiffies! g54917 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=29483
rcu: rcu_preempt kthread starved for 454 jiffies! g54917 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:25736 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 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 04/18/2026
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x532/0x9d0 kernel/locking/qspinlock.c:511
Code: 00 41 c6 45 00 00 48 8b 44 24 10 42 0f b6 04 38 84 c0 0f 85 1b 01 00 00 48 8b 44 24 08 c6 00 01 41 bd 00 80 ff ff eb 07 f3 90 <41> ff c5 74 47 43 0f b6 04 3e 84 c0 75 2b 80 3b 00 75 eb 48 89 df
RSP: 0018:ffffc900001f09c0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff888078cf0c80 RCX: ffff88801b66bc00
RDX: 0000000000000100 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60
RBP: ffffc900001f0ab0 R08: ffffffff911c55df R09: 1ffffffff2238abb
R10: dffffc0000000000 R11: fffffbfff2238abc R12: 1ffff110171e0001
R13: 00000000ffffd862 R14: 1ffff1100f19e190 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2fa2e5ce53 CR3: 000000000cf32000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x23e/0x2c0 kernel/locking/spinlock_debug.c:115
spin_lock include/linux/spinlock.h:351 [inline]
br_hello_timer_expired+0x39/0x1c0 net/bridge/br_stp_timer.c:35
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 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+0xd3/0x190 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+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 39 21 02 c3 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 e3 f3 41 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80
RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6
RAX: 30bc24284e9e4c00 RBX: ffffffff8162a8f1 RCX: 30bc24284e9e4c00
RDX: 0000000000000001 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60
RBP: ffffc90000187f20 R08: ffff8880b8f36b2b R09: 1ffff110171e6d65
R10: dffffc0000000000 R11: ffffed10171e6d66 R12: 1ffff92000030fc8
R13: dffffc0000000000 R14: 1ffff110036cd780 R15: 0000000000000000
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:178 [inline]
do_idle+0x221/0x590 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b
CPU: 0 PID: 12294 Comm: syz.1.1867 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 0b 94 cc f6 65 8b 05 4c c1 73 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90000006d60 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: a80c6c11da352100
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001
RBP: ffffc90000006de8 R08: ffffffff911c55df R09: 1ffffffff2238abb
R10: dffffc0000000000 R11: fffffbfff2238abc R12: dffffc0000000000
R13: ffff88805ca9fc80 R14: ffff8880b8e3d790 R15: 1ffff92000000dac
FS: 00007fb9dfa426c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000005a6ea000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
rps_unlock_irq_restore net/core/dev.c:241 [inline]
enqueue_to_backlog+0xa08/0xe30 net/core/dev.c:4902
netif_rx_internal+0x119/0x4e0 net/core/dev.c:5176
__netif_rx+0x78/0xc0 net/core/dev.c:5196
veth_forward_skb drivers/net/veth.c:325 [inline]
veth_xmit+0x550/0x9f0 drivers/net/veth.c:378
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3644 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660
__dev_queue_xmit+0x19a3/0x3660 net/core/dev.c:4454
__bond_start_xmit include/linux/netdevice.h:-1 [inline]
bond_start_xmit+0x12c8/0x1ca0 drivers/net/bonding/bond_main.c:5555
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3644 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660
__dev_queue_xmit+0x19a3/0x3660 net/core/dev.c:4454
dev_queue_xmit include/linux/netdevice.h:3113 [inline]
br_send_bpdu_finish net/bridge/br_stp_bpdu.c:32 [inline]
NF_HOOK include/linux/netfilter.h:304 [inline]
br_send_bpdu+0x479/0x920 net/bridge/br_stp_bpdu.c:59
br_send_config_bpdu+0x473/0x740 net/bridge/br_stp_bpdu.c:120
br_transmit_config+0x3be/0x5d0 net/bridge/br_stp.c:241
br_hold_timer_expired+0x85/0x170 net/bridge/br_stp_timer.c:137
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 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+0xd3/0x190 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+0x481/0x4f0 kernel/smp.c:418
Code: 75 11 e8 42 05 0b 00 48 85 db 75 16 e8 38 05 0b 00 eb 15 e8 31 05 0b 00 e8 0c 2e 0a 09 48 85 db 74 ea e8 22 05 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08
RSP: 0018:ffffc90004447a00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc9000ce62000 RSI: 0000000000001d83 RDI: 0000000000001d84
RBP: ffffc90004447ad0 R08: ffffffff911c55ff R09: 1ffffffff2238abf
R10: dffffc0000000000 R11: fffffbfff2238ac0 R12: 1ffff92000888f44
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000888f65
smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647
task_function_call kernel/events/core.c:120 [inline]
perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959
__do_sys_perf_event_open kernel/events/core.c:12957 [inline]
__se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12609
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb9deb9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb9dfa42028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fb9dee15fa0 RCX: 00007fb9deb9cdd9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007fb9dec32d69 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb9dee16038 R14: 00007fb9dee15fa0 R15: 00007ffde33b5628