rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=d02c/1/0x4000000000000000 softirq=16190/16193 fqs=1
rcu: (detected by 0, t=10506 jiffies, g=9265, q=806 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6135 Comm: syz.1.49 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314
Code: 48 89 44 11 20 e9 b3 91 50 ff cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 50 a0 92 65 8b 0d a8 a0 e0 10 81 e1 00 01 ff 00
RSP: 0018:ffffc90000a08d38 EFLAGS: 00000006
RAX: ffffffff81adb298 RBX: ffff8880b8727cc8 RCX: ffff888076c7da00
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000007
RBP: ffffc90000a08e90 R08: ffff88802e58b15f R09: 1ffff11005cb162b
R10: dffffc0000000000 R11: ffffed1005cb162c R12: ffff88802e58b340
R13: 0000000000000001 R14: 0000000000000001 R15: ffff888076c7e4d8
FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3168e0 CR3: 0000000026beb000 CR4: 0000000000350ef0
Call Trace:
cpu_max_bits_warn include/linux/cpumask.h:135 [inline]
cpumask_check include/linux/cpumask.h:142 [inline]
cpumask_test_cpu include/linux/cpumask.h:646 [inline]
cpu_online include/linux/cpumask.h:1205 [inline]
trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline]
__run_hrtimer kernel/time/hrtimer.c:1764 [inline]
__hrtimer_run_queues+0x568/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x37/0x90 kernel/kcov.c:294
Code: 08 50 a0 92 65 8b 15 88 a2 e0 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 3c 16 00 00 00 74 4e 8b 91 18 16 00 00 <83> fa 03 75 43 48 8b 91 20 16 00 00 44 8b 89 1c 16 00 00 49 c1 e1
RSP: 0018:ffffc90004ae7588 EFLAGS: 00000246
RAX: ffffffff822e42a6 RBX: 000000000007ffbb RCX: ffff888076c7da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff88801e67eac0 R08: ffff88801e67eabf R09: 1ffff11003ccfd57
R10: dffffc0000000000 R11: ffffed1003ccfd58 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000001 R15: ffff88801e67eab8
page_table_check_clear+0x406/0x700 mm/page_table_check.c:78
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
zap_present_folio_ptes mm/memory.c:1499 [inline]
zap_present_ptes mm/memory.c:1581 [inline]
do_zap_pte_range mm/memory.c:1682 [inline]
zap_pte_range mm/memory.c:1726 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0x3445/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x420 kernel/fork.c:1130
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f07c6d8ebe9
Code: Unable to access opcode bytes at 0x7f07c6d8ebbf.
RSP: 002b:00007fffd97ea348 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f07c6d8ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffd97ea3ac R08: 00000004d97ea43f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000005
R13: 00000000000927c0 R14: 00000000000144af R15: 00007fffd97ea400
rcu: rcu_preempt kthread starved for 10500 jiffies! g9265 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 2125 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 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 5e 0b 00 eb e4 44
RSP: 0018:ffffc900049a7660 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170e7f61 RCX: ffff8880294fda00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900049a77e0 R08: ffffffff8fa38337 R09: 1ffffffff1f47066
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffff8880b873fb08
R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faf15ee56c0 CR3: 000000000df36000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863
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:850
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245