rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=7f4c/0/0x1 softirq=36643/36644 fqs=1
rcu: (detected by 1, t=10505 jiffies, g=35073, q=173 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:204 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:242 [inline]
RIP: 0010:rb_erase+0x3f1/0xe60 lib/rbtree.c:443
Code: 03 80 3c 28 00 74 08 4c 89 e7 e8 aa 07 ce f6 4d 8b 2c 24 41 83 e5 01 49 f7 dd 4d 21 fd eb 75 48 89 d8 48 c1 e8 03 80 3c 28 00 <0f> 84 a5 05 00 00 48 89 df e8 71 08 ce f6 e9 98 05 00 00 48 b8 00
RSP: 0018:ffffc90000007ca8 EFLAGS: 00000046
RAX: 1ffff110170c507a RBX: ffff8880b86283d0 RCX: dffffc0000000000
RDX: 0000000000010000 RSI: ffff8880b86283d0 RDI: ffff88807b425308
RBP: dffffc0000000000 R08: ffffffff8fa2d9f7 R09: 1ffffffff1f45b3e
R10: dffffc0000000000 R11: fffffbfff1f45b3f R12: ffff88807b425300
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125bf9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc2e42afb8 CR3: 00000000748b4000 CR4: 00000000003526f0
Call Trace:
rb_erase_cached include/linux/rbtree.h:154 [inline]
timerqueue_del+0xae/0x100 lib/timerqueue.c:57
__remove_hrtimer kernel/time/hrtimer.c:1122 [inline]
__run_hrtimer kernel/time/hrtimer.c:1765 [inline]
__hrtimer_run_queues+0x364/0xc30 kernel/time/hrtimer.c:1849
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1911
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 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+0x13/0x20 arch/x86/kernel/paravirt.c:63
Code: 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 bd 29 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07dc0 EFLAGS: 00000242
RAX: 00000000008600d3 RBX: ffffffff8197831e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d9a73db RDI: ffffffff8be09760
RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb
R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa2d9f0
R13: 1ffffffff1bd29d0 R14: 0000000000000000 R15: 0000000000000000
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:760
start_kernel+0x386/0x3d0 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147
rcu: rcu_preempt kthread starved for 10500 jiffies! g35073 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:27016 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5290 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6902
__schedule_loop kernel/sched/core.c:6984 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6999
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 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: 6129 Comm: kworker/u8:18 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b4 9a 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 5f 96 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 43 96
RSP: 0018:ffffc9000b80f760 EFLAGS: 00000293
RAX: ffffffff81b5835d RBX: 1ffff110170c85c1 RCX: ffff8880278cdac0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000b80f8a0 R08: ffffffff8fa2d9f7 R09: 1ffffffff1f45b3e
R10: dffffc0000000000 R11: fffffbfff1f45b3f R12: ffff8880b8642e08
R13: dffffc0000000000 R14: ffff8880b873bd80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125cf9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3638ed9fb8 CR3: 000000000df3e000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2746 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2956
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:879
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245