rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=4874/1/0x4000000000000000 softirq=181327/181339 fqs=215
rcu: (t=10502 jiffies g=171373 q=1325 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10069 jiffies! g171373 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=89621
rcu: rcu_preempt kthread starved for 10072 jiffies! g171373 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:27744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
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+0x51e/0xb90 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 8e 6c 02 c3 cc cc cc cc 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 e3 e2 1a 00 fb f4 fc e9 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000a084a8 EFLAGS: 00000246
RAX: ffffffff8175b07a RBX: 0000000000000003 RCX: ffff88801d6c0000
RDX: 0000000000000100 RSI: ffffffff8def7b46 RDI: ffffffff8c27c200
RBP: 0000000000000003 R08: ffffffff9011a3b7 R09: 1ffffffff2023476
R10: dffffc0000000000 R11: fffffbfff2023477 R12: 0000000000000200
R13: 0000000000000000 R14: ffff8880a2a48158 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff88812555d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555610d64e8 CR3: 000000000e54c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
kvm_wait+0x10f/0x150 arch/x86/kernel/kvm.c:1101
pv_wait arch/x86/include/asm/paravirt-spinlock.h:83 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
__pv_queued_spin_lock_slowpath+0x74c/0xbc0 kernel/locking/qspinlock.c:325
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:35 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/paravirt-spinlock.h:66 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x26c/0x2f0 kernel/locking/spinlock_debug.c:116
spin_lock include/linux/spinlock.h:341 [inline]
__dev_xmit_skb net/core/dev.c:4224 [inline]
__dev_queue_xmit+0xbf2/0x3890 net/core/dev.c:4802
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246
dst_output include/net/dst.h:470 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
ndisc_send_skb+0xd0b/0x1670 net/ipv6/ndisc.c:512
addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4041
call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2373 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
run_timer_base kernel/time/timer.c:2394 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
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: 8e 6c 02 c3 cc cc cc cc 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 e3 e2 1a 00 fb f4 fc e9 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000246
RAX: 00000000002f8721 RBX: ffffffff819a900a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8def7b46 RDI: ffffffff8c27c200
RBP: ffffc90000197f10 R08: ffff8880b873395b R09: 1ffff110170e672b
R10: dffffc0000000000 R11: ffffed10170e672c R12: 0000000000000001
R13: 1ffff11003ad8000 R14: 0000000000000001 R15: 1ffff11003ad8000
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
CPU: 0 UID: 0 PID: 9292 Comm: syz.0.9776 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:rcu_lockdep_current_cpu_online+0x32/0x120 kernel/rcu/tree.c:4040
Code: 53 65 8b 0d 70 36 71 11 b0 01 f7 c1 00 00 f0 00 0f 85 d5 00 00 00 83 3d ef aa 66 0e 00 0f 84 c8 00 00 00 65 ff 05 4e 36 71 11 b9 a2 03 0a 89 c3 83 f8 08 0f 83 c7 00 00 00 49 be 00 00 00 00
RSP: 0018:ffffc9000d5f71a8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000201
RDX: ffff88807b44db80 RSI: ffffffff8c27c1e0 RDI: ffffffff8c27c1a0
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000008 R11: ffffffff89bc2fe0 R12: ffff88805bfa5a9c
R13: dffffc0000000000 R14: ffff88805bfa5a00 R15: ffff888067256a00
FS: 00007f6a0807b6c0(0000) GS:ffff88812545d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3bddf7 CR3: 00000000b3562000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock_held_common kernel/rcu/update.c:113 [inline]
rcu_read_lock_bh_held+0x23/0x50 kernel/rcu/update.c:374
mall_classify+0x5c/0x200 net/sched/cls_matchall.c:32
tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1764 [inline]
tcf_classify+0x4cf/0x1130 net/sched/cls_api.c:1860
hfsc_classify net/sched/sch_hfsc.c:1146 [inline]
hfsc_enqueue+0x32b/0xf50 net/sched/sch_hfsc.c:1545
dev_qdisc_enqueue+0x4e/0x290 net/core/dev.c:4151
__dev_xmit_skb net/core/dev.c:4266 [inline]
__dev_queue_xmit+0x1ad0/0x3890 net/core/dev.c:4802
packet_snd net/packet/af_packet.c:3076 [inline]
packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3108
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a0719c799
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:00007f6a0807b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6a07415fa0 RCX: 00007f6a0719c799
RDX: 0000000000000005 RSI: 0000200000000280 RDI: 0000000000000006
RBP: 00007f6a07232c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a07416038 R14: 00007f6a07415fa0 R15: 00007ffd5e35e438