rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5756/1:b..l P14380/1:b..l P15169/1:b..l P15611/3:b..l
rcu: (detected by 0, t=10506 jiffies, g=104585, q=290 ncpus=2)
task:udevd state:R running task stack:28568 pid:15611 tgid:15611 ppid:4988 task_flags:0x400040 flags:0x00080800
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
filemap_map_pages+0x1a2a/0x2100 mm/filemap.c:3942
do_fault_around mm/memory.c:5851 [inline]
do_read_fault mm/memory.c:5884 [inline]
do_fault mm/memory.c:6027 [inline]
do_pte_missing+0x1f38/0x33f0 mm/memory.c:4550
handle_pte_fault mm/memory.c:6411 [inline]
__handle_mm_fault mm/memory.c:6549 [inline]
handle_mm_fault+0x1bd7/0x3170 mm/memory.c:6718
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fb92956e600
RSP: 002b:00007ffdca9f51f8 EFLAGS: 00010206
RAX: 0000000000000030 RBX: 0000000000000004 RCX: 000055ad1040de90
RDX: 0000000000000010 RSI: 000055ad1040dea0 RDI: 000055ad1040de90
RBP: 000055ad103f18e0 R08: 0000000000000004 R09: 0000000000000010
R10: 000055ad097145e0 R11: 0000000000000004 R12: 0000000000000003
R13: 0000000000000000 R14: 000055ad097145e0 R15: 0000000000000004
task:syz-executor state:R running task stack:21992 pid:15169 tgid:15169 ppid:1 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x90 kernel/kcov.c:313
Code: 11 10 48 89 74 11 18 48 89 44 11 20 e9 14 7b 4a ff cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 15 e8 69 73 11 65 8b 0d 09 6a 73
RSP: 0018:ffffc900056af860 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff823c82b2 RCX: 0000000000000046
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff823c82b2 R09: ffffffff8e95cd60
R10: dffffc0000000000 R11: fffff940004c516f R12: 0000000000000260
R13: dffffc0000000000 R14: 0000000000098a2d R15: ffff88801c880000
lookup_page_ext mm/page_ext.c:258 [inline]
page_ext_get+0x1bb/0x2e0 mm/page_ext.c:532
__reset_page_owner+0x28/0x1f0 mm/page_owner.c:306
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
__free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
vfree+0x1d1/0x2f0 mm/vmalloc.c:3472
kcov_put kernel/kcov.c:442 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:543
__fput+0x44f/0xa60 fs/file_table.c:510
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x22c0 kernel/exit.c:975
do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0887f5d68e
RSP: 002b:00007ffd628cadc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: 0000000000000060 RBX: 0000555589543500 RCX: 00007f0887f5d68e
RDX: 0000000000000060 RSI: 00007f0888d44670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd628cae44 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f0888d44670 R15: 0000000000000000
task:kworker/u8:21 state:R running task stack:24168 pid:14380 tgid:14380 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound toggle_allocation_gate
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
__text_poke+0x7b9/0x9a0 arch/x86/kernel/alternative.c:2648
text_poke arch/x86/kernel/alternative.c:2672 [inline]
smp_text_poke_batch_finish+0x3b2/0x1160 arch/x86/kernel/alternative.c:2980
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
toggle_allocation_gate+0x1fe/0x290 mm/kfence/core.c:913
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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:kworker/1:5 state:R running task stack:22840 pid:5756 tgid:5756 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events drain_vmap_area_work
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0x29/0x40 kernel/rcu/update.c:321
Code: 90 f3 0f 1e fa 31 c0 83 3d 63 ed 87 04 00 74 1d 83 3d 1a 1f 88 04 00 74 14 65 48 8b 0d 58 65 90 07 31 c0 83 b9 8c 0b 00 00 00 <0f> 94 c0 e9 4a 76 67 f5 cc cc cc cc cc cc cc cc cc cc cc cc cc cc
RSP: 0018:ffffc900046873b0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff82206cc6 RCX: ffff88807ac88000
RDX: 00000000c5e95e85 RSI: ffffffff8e219b45 RDI: ffffffff8c28af60
RBP: dffffc0000000000 R08: ffffffff8176f256 R09: ffffffff8e95cd60
R10: dffffc0000000000 R11: ffffffff81b0ebd0 R12: ffffc900046874c0
R13: 1ffff920008d0e91 R14: ffffc90004687488 R15: ffffffff8176f256
rcu_read_lock include/linux/rcupdate.h:839 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xcc/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6250 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6377
__merge_or_add_vmap_area mm/vmalloc.c:1473 [inline]
merge_or_add_vmap_area mm/vmalloc.c:1523 [inline]
decay_va_pool_node+0x786/0xec0 mm/vmalloc.c:2250
__purge_vmap_area_lazy+0x160/0xb40 mm/vmalloc.c:2355
drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2430
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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
rcu: rcu_preempt kthread starved for 10506 jiffies! g104585 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5788 Comm: kworker/0:7 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events fqdir_free_fn
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_single+0x3a4/0x5b0 kernel/smp.c:702
Code: e6 01 31 ff e8 9d 20 0c 00 41 83 e4 01 75 11 e8 52 1c 0c 00 4d 89 ec eb 41 e8 48 1c 0c 00 eb 3a 4d 89 ec f3 90 42 0f b6 04 33 <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 2a 1c 0c 00 eb e5 44 89
RSP: 0018:ffffc90005067920 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff92000a0cf31 RCX: ffff88801eba0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005067a18 R08: ffffffff9030b6f7 R09: 1ffffffff20616de
R10: dffffc0000000000 R11: ffffffff81746300 R12: 1ffff92000a0cf2c
R13: 1ffff92000a0cf2c R14: dffffc0000000000 R15: ffffc90005067988
FS: 0000000000000000(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5b54bea540 CR3: 0000000063e28000 CR4: 0000000000350ef0
Call Trace:
rcu_barrier+0x360/0x580 kernel/rcu/tree.c:3880
fqdir_free_fn+0x33/0x140 net/ipv4/inet_fragment.c:166
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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