rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (3 ticks this GP) idle=7684/1/0x4000000000000000 softirq=22796/22796 fqs=7
rcu: (detected by 1, t=10502 jiffies, g=18669, q=936 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6312 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:preempt_count_add+0x1f/0x150 kernel/sched/core.c:5858
Code: 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 c7 c0 80 d3 23 9b 55 48 ba 00 00 00 00 00 fc ff df 48 89 c1 53 83 e0 07 89 fb <48> c1 e9 03 83 c0 03 65 01 3d 43 66 3e 12 0f b6 14 11 38 d0 7c 08
RSP: 0018:ffffc90000007d30 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff9b23d380
RDX: dffffc0000000000 RSI: ffffffff9b4f32b8 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000005 R09: ffffc90000007d80
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffff888078c0d300 R14: 0000000000000001 R15: 1ffff92000000fb0
FS: 00005555774c5500(0000) GS:ffff8881242db000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faae335d2d8 CR3: 000000007798c000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:131 [inline]
_raw_spin_lock_irqsave+0x1e/0x60 kernel/locking/spinlock.c:166
debug_object_activate+0x144/0x490 lib/debugobjects.c:835
debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline]
debug_activate kernel/time/hrtimer.c:528 [inline]
enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109
__run_hrtimer kernel/time/hrtimer.c:1946 [inline]
__hrtimer_run_queues+0x73d/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:202 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:232 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:folio_test_mlocked include/linux/page-flags.h:642 [inline]
RIP: 0010:__free_pages_prepare mm/page_alloc.c:1326 [inline]
RIP: 0010:__free_frozen_pages+0x1dc/0x1040 mm/page_alloc.c:2943
Code: 08 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 49 0b 00 00 41 f6 46 08 01 0f 85 8a 08 00 00 be 08 00 00 00 4c 89 f7 e8 24 a6 0e 00 <4c> 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f
RSP: 0018:ffffc90002fc7ba0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8268934c
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffea00015367c0
RBP: 0000000000000000 R08: 0000000000000000 R09: fffff940002a6cf8
R10: ffffea00015367c7 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea00015367c8 R14: ffffea00015367c0 R15: ffffea00015367c0
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_lru_noprof+0x246/0x6e0 mm/slub.c:4917
__d_alloc+0x34/0xa40 fs/dcache.c:1807
d_alloc_pseudo+0x1c/0xc0 fs/dcache.c:1938
alloc_path_pseudo fs/file_table.c:405 [inline]
alloc_file_pseudo+0xcf/0x230 fs/file_table.c:421
sock_alloc_file+0x50/0x210 net/socket.c:543
sock_map_fd net/socket.c:573 [inline]
__sys_socket+0x1c0/0x260 net/socket.c:1815
__do_sys_socket net/socket.c:1820 [inline]
__se_sys_socket net/socket.c:1818 [inline]
__x64_sys_socket+0x72/0xb0 net/socket.c:1818
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faae3191c47
Code: f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 29 00 00 00 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:00007ffcd84037c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007faae3191c47
RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 00007ffcd8403ebc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000032
R13: 000000000001d5b9 R14: 00007ffcd8403f10 R15: 0000000000000003
rcu: rcu_preempt kthread starved for 10471 jiffies! g18669 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:26760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 139 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x1700 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 09 80 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90002e97870 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fcfafd
RDX: ffff888020714a00 RSI: ffffffff81fcfad7 RDI: ffff888020714a00
RBP: ffff8880b8443320 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed1017088665 R14: 0000000000000001 R15: ffff8880b853c5c0
FS: 0000000000000000(0000) GS:ffff8881243db000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000600 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x37a/0x550 kernel/jump_label.c:910
static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:906 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245