rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=7bb/1/0x4000000000000000 softirq=6602/6607 fqs=20
(detected by 0, t=10504 jiffies, g=7361, q=481)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4323 Comm: syz.1.23 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4702 [inline]
RIP: 0010:__lock_acquire+0x6f6/0x7d10 kernel/locking/lockdep.c:4962
Code: fe 0f 88 70 01 00 00 44 89 fb 81 e3 ff ff ff 7f 83 f8 31 73 43 48 8d 04 9b 49 8d 5c c5 00 48 89 d8 48 c1 e8 03 42 0f b6 04 00 <84> c0 75 45 8b 1b 48 8b 44 24 58 42 0f b6 04 00 84 c0 75 55 48 8b
RSP: 0018:ffffc90000dd0860 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff88807b47e478 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d80c0
RBP: ffffc90000dd0ab0 R08: dffffc0000000000 R09: 1ffffffff203b018
R10: dffffc0000000000 R11: fffffbfff203b019 R12: 0000000000000000
R13: ffff88807b47e450 R14: 0000000000000003 R15: 0000000000000001
FS: 00007f0825d5e6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000012c0 CR3: 0000000072576000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
debug_object_activate+0x63/0x4e0 lib/debugobjects.c:694
debug_hrtimer_activate kernel/time/hrtimer.c:410 [inline]
debug_activate kernel/time/hrtimer.c:465 [inline]
enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1069
__run_hrtimer kernel/time/hrtimer.c:1702 [inline]
__hrtimer_run_queues+0x5fa/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/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 4f 9d 8b f7 65 8b 05 70 86 3b 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc900014eee40 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: db21361b9e79db00
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: 0000000000000001
RBP: ffffc900014eeed0 R08: ffffffff901d818f R09: 1ffffffff203b031
R10: dffffc0000000000 R11: fffffbfff203b032 R12: dffffc0000000000
R13: 0000000000008001 R14: ffff888076b392e8 R15: 1ffff9200029ddc8
spin_unlock_irqrestore include/linux/spinlock.h:419 [inline]
taprio_change+0x409d/0x4ef0 net/sched/sch_taprio.c:1589
qdisc_create+0x7dd/0x1190 net/sched/sch_api.c:1255
tc_modify_qdisc+0xad0/0x17c0 net/sched/sch_api.c:-1
rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5688
netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
__sys_sendmsg net/socket.c:2528 [inline]
__do_sys_sendmsg net/socket.c:2537 [inline]
__se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0827b04e59
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:00007f0825d5e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0827d7dfa0 RCX: 00007f0827b04e59
RDX: 0000000000000010 RSI: 00002000000012c0 RDI: 0000000000000008
RBP: 00007f0827b9ad6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0827d7e038 R14: 00007f0827d7dfa0 R15: 00007ffdd7c35928
rcu: rcu_preempt kthread starved for 10405 jiffies! g7361 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:26960 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 4236 Comm: kworker/0:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events once_deferred
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x843/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xbb5/0xd90 kernel/smp.c:969
Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 d9 62 0b 00 83 e3 01 75 07 e8 6f 5f 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7
RSP: 0018:ffffc900031cf900 EFLAGS: 00000293
RAX: ffffffff816de9a8 RBX: 0000000000000001 RCX: ffff8880236cbb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900031cfa40 R08: ffffffff901d80c7 R09: 1ffffffff203b018
R10: dffffc0000000000 R11: fffffbfff203b019 R12: ffff8880b91405c8
R13: 1ffff110172280b9 R14: ffff8880b903b3c0 R15: 0000000000000001
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1134
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:1442 [inline]
text_poke_bp_batch+0x2b0/0x830 arch/x86/kernel/alternative.c:1642
text_poke_flush arch/x86/kernel/alternative.c:1833 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1840
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xbd/0x1a0 kernel/jump_label.c:207
static_key_disable+0x16/0x20 kernel/jump_label.c:215
once_deferred+0x6b/0xb0 lib/once.c:20
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287