rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=5c0c/1/0x4000000000000000 softirq=43014/43020 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9795/1:b..l
rcu: (detected by 1, t=10505 jiffies, g=35813, q=263 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9794 Comm: dhcpcd-run-hook Not tainted 6.15.0-rc6-syzkaller-00025-g627277ba7c23 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_preemption_disabled+0x40/0x120 lib/smp_processor_id.c:55
Code: 08 65 8b 05 56 0e 23 07 65 8b 0d 4b 0e 23 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 2b 0e 23 07 48 3b 4c 24 08 0f 85 cc 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d e9 51 b5 02 00 cc 48 c7 04 24 00 00
RSP: 0018:ffffc90000007ba0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888020eae2e8 RCX: f298700ec90b5600
RDX: 0000000000010000 RSI: ffffffff8bc104c0 RDI: ffffffff8bc10480
RBP: ffff8880289fa150 R08: ffff8880289fa087 R09: 1ffff1100513f410
R10: dffffc0000000000 R11: ffffed100513f411 R12: ffff888020eae340
R13: ffffffff8970ae9f R14: ffff888020eae300 R15: ffff8880243fc000
FS: 0000000000000000(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f715ff8 CR3: 000000007a8f2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:736
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5877
__raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
advance_sched+0x99f/0xc90 net/sched/sch_taprio.c:981
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5250
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 ef a0 bf 09 e8 5a 65 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9001bf66f98 EFLAGS: 00000282
RAX: f298700ec90b5600 RBX: 0000000000000000 RCX: f298700ec90b5600
RDX: 0000000000000006 RSI: ffffffff8d7387c2 RDI: ffffffff8bc104e0
RBP: ffffc9001bf66ff0 R08: ffffffff8f7dd277 R09: 1ffffffff1efba4e
R10: dffffc0000000000 R11: fffffbfff1efba4f R12: ffff88802fe33c00
R13: dffffc0000000000 R14: ffff88801db4da00 R15: ffff8880b883a558
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0x1697/0x4c70 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 e3 3c 55 00 cc cc cc 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 0c 25 08 50 72 92 <65> 8b 15 78 5f b2 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc9001bf67380 EFLAGS: 00000246
RAX: ffffffff82173569 RBX: ffffea00014f4c80 RCX: ffff88802fe33c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffea00014f4c87 R09: 1ffffd400029e990
R10: dffffc0000000000 R11: fffff9400029e991 R12: dffffc0000000000
R13: 1ffffd400029e991 R14: ffffea00014f4c88 R15: 1ffffd400029e990
free_swap_cache+0x109/0x300 mm/swap_state.c:227
free_pages_and_swap_cache+0x17a/0x520 mm/swap_state.c:260
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:496
exit_mmap+0x474/0xba0 mm/mmap.c:1297
__mmput+0x118/0x410 kernel/fork.c:1379
exec_mmap+0x680/0x7a0 fs/exec.c:1009
begin_new_exec+0x129c/0x2120 fs/exec.c:1264
load_elf_binary+0x973/0x27b0 fs/binfmt_elf.c:1001
search_binary_handler fs/exec.c:1778 [inline]
exec_binprm fs/exec.c:1810 [inline]
bprm_execve+0x999/0x1440 fs/exec.c:1862
do_execveat_common+0x510/0x6a0 fs/exec.c:1968
do_execve fs/exec.c:2042 [inline]
__do_sys_execve fs/exec.c:2118 [inline]
__se_sys_execve fs/exec.c:2113 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2961161107
Code: Unable to access opcode bytes at 0x7f29611610dd.
RSP: 002b:00007ffd5a29b6a8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055b6c8956080 RCX: 00007f2961161107
RDX: 000055b6c89560a8 RSI: 000055b6c8956080 RDI: 000055b6c8956138
RBP: 000055b6c8956138 R08: 00007ffd5a29feb8 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 000055b6c89560a8
R13: 00007f2961326e8b R14: 000055b6c89560a8 R15: 0000000000000000
task:syz.3.1028 state:R running task stack:25512 pid:9795 tgid:9792 ppid:5826 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5870
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 4b 10 d4 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000ab46e98 EFLAGS: 00000206
RAX: 479f898b59f58600 RBX: 0000000000000000 RCX: 479f898b59f58600
RDX: 0000000000000000 RSI: ffffffff8d9226df RDI: ffffffff8bc104e0
RBP: ffffffff8171ca05 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171ca05 R12: 0000000000000002
R13: ffffffff8df3dce0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4a0 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
prep_new_page mm/page_alloc.c:1726 [inline]
get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2392
pagetable_alloc_noprof include/linux/mm.h:3002 [inline]
__pte_alloc_one_noprof include/asm-generic/pgalloc.h:70 [inline]
pte_alloc_one+0x1e/0x160 arch/x86/mm/pgtable.c:17
__pte_alloc+0x25/0x160 mm/memory.c:430
mfill_atomic mm/userfaultfd.c:788 [inline]
mfill_atomic_copy+0x844/0x1470 mm/userfaultfd.c:865
userfaultfd_copy fs/userfaultfd.c:1614 [inline]
userfaultfd_ioctl+0x29ba/0x4bc0 fs/userfaultfd.c:2031
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdaee98e969
RSP: 002b:00007fdaef7b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdaeebb6080 RCX: 00007fdaee98e969
RDX: 0000200000000040 RSI: 00000000c028aa03 RDI: 0000000000000003
RBP: 00007fdaeea10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdaeebb6080 R15: 00007ffe9f1c3268
rcu: rcu_preempt kthread starved for 10500 jiffies! g35813 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 7591 Comm: kworker/u8:14 Not tainted 6.15.0-rc6-syzkaller-00025-g627277ba7c23 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xe69/0x11c0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 10 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 bb 68 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 a0 68 0b
RSP: 0018:ffffc9001a97f700 EFLAGS: 00000293
RAX: ffffffff81b48800 RBX: ffff8880b893abc0 RCX: ffff8880624cbc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9001a97f860 R08: ffffffff8f7dd277 R09: 1ffffffff1efba4e
R10: dffffc0000000000 R11: fffffbfff1efba4f R12: 1ffff11017108221
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8841108
FS: 0000000000000000(0000) GS:ffff8881261fb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000036000 CR3: 000000000dd38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2751 [inline]
text_poke_bp_batch+0x319/0x940 arch/x86/kernel/alternative.c:2961
text_poke_flush arch/x86/kernel/alternative.c:3152 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:3159
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:3238 [inline]
process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245