rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=bd9c/1/0x4000000000000000 softirq=23579/23585 fqs=3
rcu: (detected by 0, t=10503 jiffies, g=16617, q=768 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6664 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0x31b/0xd20 kernel/locking/lockdep.c:-1
Code: e2 01 c1 e2 12 44 09 e2 41 c1 e6 14 41 09 d6 8b 54 24 10 c1 e2 13 c1 e5 15 09 d5 09 cd 44 09 f5 41 89 6c c7 20 45 89 44 c7 24 <4c> 89 7c 24 10 4d 8d 34 c7 81 e5 ff 1f 00 00 48 0f a3 2d 8e aa d8
RSP: 0018:ffffc90000a08ad0 EFLAGS: 00000006
RAX: 0000000000000014 RBX: ffffffff99a4a1b0 RCX: 0000000000000000
RDX: 0000000000080000 RSI: 0000000000004000 RDI: ffff888030b05ac0
RBP: 00000000000c4000 R08: 0000000000000000 R09: ffffffff8492d87a
R10: ffffc90000a08cb0 R11: fffff52000141198 R12: 0000000000004000
R13: 0000000000000000 R14: 0000000000044000 R15: ffff888030b065f0
FS: 0000000000000000(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa155473286 CR3: 0000000072058000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:873
debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:483
__run_hrtimer kernel/time/hrtimer.c:1745 [inline]
__hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:down_write+0x4/0x1f0 kernel/locking/rwsem.c:1588
Code: c7 c7 94 12 7d 8f e8 fb 87 dd f6 e9 f6 fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 54 53 48 83 e4 e0 48 83 ec 60 48 89 fb
RSP: 0018:ffffc90003f9f4f0 EFLAGS: 00000293
RAX: ffffffff82120ce3 RBX: 1ffff1100f152952 RCX: ffff888030b05ac0
RDX: 0000000000000000 RSI: ffffffff8d8f4722 RDI: ffff88803069ddd8
RBP: ffff888079273bb0 R08: ffff888027f4b6c3 R09: 1ffff11004fe96d8
R10: dffffc0000000000 R11: ffffed1004fe96d9 R12: ffff888078a94a90
R13: 0000000000000000 R14: ffff88803069ddd0 R15: ffff888027f4b670
lock_anon_vma_root mm/rmap.c:249 [inline]
unlink_anon_vmas+0x100/0x670 mm/rmap.c:407
free_pgtables+0x72b/0x9c0 mm/memory.c:413
exit_mmap+0x43c/0xb40 mm/mmap.c:1291
__mmput+0x118/0x430 kernel/fork.c:1133
exec_mmap+0x6ac/0x7d0 fs/exec.c:901
begin_new_exec+0x12d6/0x2160 fs/exec.c:1156
load_elf_binary+0x998/0x2740 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1670 [inline]
exec_binprm fs/exec.c:1702 [inline]
bprm_execve+0x99c/0x1450 fs/exec.c:1754
do_execveat_common+0x510/0x6a0 fs/exec.c:1860
do_execve fs/exec.c:1934 [inline]
__do_sys_execve fs/exec.c:2010 [inline]
__se_sys_execve fs/exec.c:2005 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2005
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1553b9107
Code: Unable to access opcode bytes at 0x7fa1553b90dd.
RSP: 002b:00007ffe6d153938 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 0000560621f0a0c8 RCX: 00007fa1553b9107
RDX: 0000560621f0a0e8 RSI: 0000560621f0a0c8 RDI: 0000560621f0a170
RBP: 0000560621f0a170 R08: 00007ffe6d157eae R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000560621f0a0e8
R13: 00007fa15557ee8b R14: 0000560621f0a0e8 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10490 jiffies! g16617 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full)
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+0xd33/0x12d0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 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 45 6f
RSP: 0018:ffffc90000127640 EFLAGS: 00000293
RAX: ffffffff81b4974b RBX: 1ffff11017127ffd RCX: ffff88801c6f0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900001277c0 R08: ffffffff8f7ce277 R09: 1ffffffff1ef9c4e
R10: dffffc0000000000 R11: fffffbfff1ef9c4f R12: ffff8880b893ffe8
R13: dffffc0000000000 R14: ffff8880b883b240 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa1553772a0 CR3: 000000000dd38000 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:2713 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2923
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:852
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245