rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5875/1:b..l P6178/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=11909, q=367 ncpus=2)
task:syz.1.70 state:R running task stack:26896 pid:6178 tgid:6178 ppid:5943 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0xb0/0x340 kernel/locking/lockdep.c:5844
Code: a5 f1 03 0e 00 0f 84 fa 00 00 00 65 8b 05 a8 87 01 11 85 c0 0f 85 eb 00 00 00 65 48 8b 04 25 08 b0 9f 92 83 b8 2c 0b 00 00 00 <0f> 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89
RSP: 0000:ffffc9000217f098 EFLAGS: 00000246
RAX: ffff88802b041e80 RBX: 0000000000000000 RCX: b96b0c396fd4db00
RDX: 0000000000000000 RSI: ffffffff81742fa2 RDI: 1ffffffff1c27e5c
RBP: ffffffff81742f85 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000217f258 R11: ffffffff81ad9d50 R12: 0000000000000002
R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline]
vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2540
folio_prealloc+0x30/0x180 mm/memory.c:-1
wp_page_copy mm/memory.c:3719 [inline]
do_wp_page+0x1231/0x5750 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fb119664f87
RSP: 002b:00007fffc4569310 EFLAGS: 00010207
RAX: 0000000000000001 RBX: 00007fb1199e5fa8 RCX: 00007fb11978f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fb1199e5fa8
RBP: 0000000000000000 R08: 00007fffc45691a7 R09: 00000001c45695ff
R10: 00007fb1199e5fa0 R11: 0000000000000246 R12: 00007fb1199e5fac
R13: 00007fb1199e5fa0 R14: 0000000000001c4d R15: 0000000000000003
task:udevd state:R running task stack:26312 pid:5875 tgid:5875 ppid:5199 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
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 44 41 01 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900043ff018 EFLAGS: 00000206
RAX: 9e09ce338e07d700 RBX: 0000000000000000 RCX: 9e09ce338e07d700
RDX: 00000000d41df51d RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: ffffffff81742f85 R08: ffffffff81742f85 R09: ffffffff8e13f2e0
R10: ffffc900043ff1d8 R11: ffffffff81ad9d50 R12: 0000000000000002
R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5661 [inline]
__kmalloc_noprof+0x41d/0x800 mm/slub.c:5673
kmalloc_noprof include/linux/slab.h:961 [inline]
tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771
security_file_open+0xb1/0x270 security/security.c:2636
do_dentry_open+0x384/0x14e0 fs/open.c:939
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:4627 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4786
do_filp_open+0x1fa/0x410 fs/namei.c:4813
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe6810a7407
RSP: 002b:00007ffef4b501d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fe68178f880 RCX: 00007fe6810a7407
RDX: 0000000000080000 RSI: 000055ff69671e80 RDI: ffffffffffffff9c
RBP: 000055ff69671e80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000009
rcu: rcu_preempt kthread starved for 10587 jiffies! g11909 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:27728 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6181 Comm: syz.0.71 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_release+0x5a/0x3b0 kernel/locking/lockdep.c:5881
Code: 11 83 f8 08 0f 83 87 02 00 00 89 c0 48 0f a3 05 dc 90 03 0e 73 0d e8 f5 f8 08 00 84 c0 0f 84 a3 02 00 00 83 3d f6 c0 03 0e 00 <0f> 84 3e 02 00 00 65 8b 05 f9 56 01 11 85 c0 0f 85 2f 02 00 00 65
RSP: 0018:ffffc90000a08bd0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff8880308164e8 RCX: 1708eb668120f600
RDX: 0000000000010000 RSI: ffffffff8be07940 RDI: ffffffff8be07900
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141164 R12: ffff88807cadef00
R13: ffffffff81877109 R14: ffffffff8e13f2e0 R15: 1ffff11006102c9d
FS: 00007fb31e28c6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000003425c000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
__lock_task_sighand+0x2af/0x2e0 kernel/signal.c:1385
lock_task_sighand include/linux/sched/signal.h:748 [inline]
posixtimer_send_sigqueue+0x27d/0xa70 kernel/signal.c:1990
posix_timer_queue_signal kernel/time/posix-timers.c:364 [inline]
posix_timer_fn+0x121/0x1c0 kernel/time/posix-timers.c:379
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1a 4e 3e f6 48 89 df e8 52 c5 3e f6 e8 4d 43 69 f6 fb bf 01 00 00 00 82 ba 30 f6 65 8b 05 db 5f 3f 07 85 c0 74 07 5b e9 c1 4b 00 00
RSP: 0018:ffffc9000214fc60 EFLAGS: 00000286
RAX: 1708eb668120f600 RBX: ffff88807cadef00 RCX: 1708eb668120f600
RDX: 0000000000000000 RSI: ffffffff8d997e54 RDI: 0000000000000001
RBP: 0000000000000021 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee
R10: dffffc0000000000 R11: fffffbfff1f445ef R12: 1ffff1100f95be73
R13: 0000000000000000 R14: 000000001c000004 R15: ffff88807cadf398
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11a7/0x1340 kernel/signal.c:3037
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb31d38f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb31e28c0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb31d5e5fa8 RCX: 00007fb31d38f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb31d5e5fa8
RBP: 00007fb31d5e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb31d5e6038 R14: 00007ffca6e5a0f0 R15: 00007ffca6e5a1d8