rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=0c7c/1/0x4000000000000000 softirq=16942/16942 fqs=2
rcu: 	(detected by 0, t=10505 jiffies, g=15601, q=1414 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 4987 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:preempt_count_add+0x42/0x190 kernel/sched/core.c:5985
Code: 78 9a 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 ea 00 00 00 83 3d be b6 e3 18 00 75 07 65 8b 05 65 61 d8 11 65 01 3d 5e 61 d8 11 <48> c7 c0 80 25 78 9a 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e5 00
RSP: 0018:ffffc90000a08990 EFLAGS: 00000002
RAX: 0000000000010101 RBX: ffff8880b87281c0 RCX: ffffffff9a782503
RDX: 0000000000010100 RSI: ffffffff8c4bdb60 RDI: 0000000000000001
RBP: ffff88807ae71300 R08: ffffffff90579037 R09: 1ffffffff20af206
R10: dffffc0000000000 R11: fffffbfff20af207 R12: ffff8880b87281c0
R13: 0000000000000001 R14: ffff8880b8728360 R15: dffffc0000000000
FS:  00007f388fa86880(0000) GS:ffff888125053000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555ead9a38 CR3: 000000007e0fc000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:141 [inline]
 _raw_spin_lock_irq+0x21/0x50 kernel/locking/spinlock.c:174
 __run_hrtimer kernel/time/hrtimer.c:2036 [inline]
 __hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:98 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x97/0x2c0 mm/kasan/generic.c:200
Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 9e 01 00 00 49 ff c3 48 ff c3 75 ee e9 1d 01 00 00 44 89 dd
RSP: 0018:ffffc90000a08ca8 EFLAGS: 00000246
RAX: ffffffff82091501 RBX: ffffffffffffffff RCX: ffffffff820915d7
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea000513b300
RBP: ffffea000513b308 R08: ffffea000513b307 R09: 1ffffd4000a27660
R10: dffffc0000000000 R11: fffff94000a27660 R12: 0000000000000001
R13: 1ffffd4000a27661 R14: fffff94000a27661 R15: 1ffffd4000a27660
 instrument_atomic_read include/linux/instrumented.h:82 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 folio_test_head include/linux/page-flags.h:843 [inline]
 folio_test_large include/linux/page-flags.h:864 [inline]
 folio_nr_pages include/linux/mm.h:2784 [inline]
 __folio_end_writeback+0x67/0x770 mm/page-writeback.c:2960
 folio_end_writeback_no_dropbehind+0x151/0x290 mm/filemap.c:1666
 folio_end_writeback+0xea/0x220 mm/filemap.c:1692
 blk_update_request+0x57b/0xe50 block/blk-mq.c:1016
 scsi_end_request+0x77/0x820 drivers/scsi/scsi_lib.c:671
 scsi_io_completion+0x133/0x360 drivers/scsi/scsi_lib.c:1112
 blk_complete_reqs block/blk-mq.c:1222 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1227
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 common_interrupt+0xbb/0xe0 arch/x86/kernel/irq.c:273
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x4e/0xb0 kernel/rcu/tree.c:752
Code: ff df 4c 8d 34 dd d0 d7 4f 8e 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2c b6 88 00 48 c7 c3 d8 08 6e 93 49 03 1e <48> 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d b9
RSP: 0018:ffffc90004387920 EFLAGS: 00000287
RAX: 1ffffffff1c9fafb RBX: ffff8880b87338d8 RCX: 0000000080000001
RDX: ffff88807e3edd00 RSI: ffffffff8c4bdb60 RDI: ffffffff8c4bdb20
RBP: ffffc90004387a10 R08: ffffffff90579037 R09: 1ffffffff20af206
R10: dffffc0000000000 R11: fffffbfff20af207 R12: ffffc90004387a10
R13: 0000000000000001 R14: ffffffff8e4fd7d8 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 prepend_path+0x44d/0x840 fs/d_path.c:174
 d_absolute_path+0xa1/0x140 fs/d_path.c:234
 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
 tomoyo_realpath_from_path+0x30d/0x640 security/tomoyo/realpath.c:271
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827
 security_inode_getattr+0x12b/0x310 security/security.c:1895
 vfs_getattr fs/stat.c:259 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 __do_sys_newfstat fs/stat.c:551 [inline]
 __se_sys_newfstat fs/stat.c:546 [inline]
 __x64_sys_newfstat+0x133/0x270 fs/stat.c:546
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f388f311ad7
Code: 73 01 c3 48 8b 0d 21 f3 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffc08cce668 EFLAGS: 00000202 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f388f311ad7
RDX: 0000000000090800 RSI: 00007ffc08cce670 RDI: 000000000000000d
RBP: 00007ffc08cce670 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 00005582175fe7b0
R13: 00000000000000ff R14: 00005581e16a8be0 R15: 00007ffc08cce990
 </TASK>
rcu: rcu_preempt kthread starved for 10497 jiffies! g15601 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:28192 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 790 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x10b0/0x14b0 kernel/smp.c:892
Code: c0 75 73 41 8b 1e 89 de 83 e6 01 31 ff e8 d8 22 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1e 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1e 0c
RSP: 0018:ffffc90004767720 EFLAGS: 00000293
RAX: ffffffff81bae317 RBX: dffffc0000000000 RCX: ffff888026bddd00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004767860 R08: ffffffff90579037 R09: 1ffffffff20af206
R10: dffffc0000000000 R11: fffffbfff20af207 R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888124f53000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000090b1c9f0000 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 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+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
 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+0xab/0x290 mm/kfence/core.c:911
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>