rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=c69c/1/0x4000000000000000 softirq=158966/158966 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P25863/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=170201, q=454 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25867 Comm: syz.6.3845 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:base_update_next_timer kernel/time/hrtimer.c:1128 [inline]
RIP: 0010:__remove_hrtimer+0x1be/0x3e0 kernel/time/hrtimer.c:1162
Code: 8d 67 60 4c 89 e0 48 c1 e8 03 80 3c 28 00 74 08 4c 89 e7 e8 e4 27 7e 00 4d 8b 24 24 4d 85 e4 74 24 e8 a6 ec 12 00 49 83 c4 28 <4c> 89 e0 48 c1 e8 03 80 3c 28 00 74 08 4c 89 e7 e8 bd 27 7e 00 49
RSP: 0018:ffffc90000a08d90 EFLAGS: 00000086
RAX: ffffffff81b2d21a RBX: 1ffff1100baf0067 RCX: ffff88802a9b5c40
RDX: 0000000000010000 RSI: 0000000000000000 RDI: ffff88805d780328
RBP: dffffc0000000000 R08: ffff88805d780327 R09: ffff88805d780318
R10: dffffc0000000000 R11: ffffed100baf0065 R12: ffff888035eba028
R13: 0000000000000000 R14: ffff88805d780300 R15: ffff8880b87283c0
FS: 00007fea24f346c0(0000) GS:ffff88812531e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000360f6000 CR4: 0000000000350ef0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:1910 [inline]
__hrtimer_run_queues+0x299/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:arch_stack_walk+0x111/0x150 arch/x86/kernel/stacktrace.c:27
Code: ff ff 00 74 38 4c 8d bd 78 ff ff ff 4c 89 ff e8 15 60 09 00 48 85 c0 74 24 48 89 df 48 89 c6 4d 89 f3 2e e8 41 8a 4c 0a 84 c0 <74> 11 4c 89 ff e8 45 61 09 00 83 bd 78 ff ff ff 00 75 cf 65 48 8b
RSP: 0018:ffffc9000d3cee08 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc9000d3ceec0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff823ac18d RDI: ffffc9000d3ceec0
RBP: ffffc9000d3cee90 R08: ffffc9000d3ceed0 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff81b0f560 R12: ffff88802a9b5c40
R13: 1ffff11005536c46 R14: ffffffff81b0f560 R15: ffffc9000d3cee08
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 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+0x231/0x280 mm/page_alloc.c:1858
prep_new_page mm/page_alloc.c:1866 [inline]
get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2509
shmem_alloc_folio mm/shmem.c:1933 [inline]
shmem_alloc_and_add_folio+0x442/0xf80 mm/shmem.c:1975
shmem_get_folio_gfp+0x5a9/0x1670 mm/shmem.c:2564
shmem_fault+0x179/0x390 mm/shmem.c:2765
__do_fault+0x138/0x2a0 mm/memory.c:5458
do_read_fault mm/memory.c:5893 [inline]
do_fault mm/memory.c:6027 [inline]
do_pte_missing+0x2093/0x33f0 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
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x1683/0x2720 mm/gup.c:1428
populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
__mm_populate+0x25f/0x390 mm/gup.c:1963
mm_populate include/linux/mm.h:4137 [inline]
vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea23f9c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fea24f34028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fea24215fa0 RCX: 00007fea23f9c819
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fea24032c91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fea24216038 R14: 00007fea24215fa0 R15: 00007ffea48ee688
task:syz.4.3844 state:R running task stack:25768 pid:25863 tgid:25862 ppid:24457 task_flags:0x40044c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7188
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7369
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]
zap_pte_range mm/memory.c:1948 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x3d17/0x4b40 mm/memory.c:2093
unmap_vmas+0x379/0x530 mm/memory.c:2162
exit_mmap+0x280/0x9e0 mm/mmap.c:1300
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x18e/0x250 kernel/exit.c:581
do_exit+0x6a2/0x22c0 kernel/exit.c:963
do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x480 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:328 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb1b79c819
RSP: 002b:00007fbb1c7310e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fbb1ba15fa8 RCX: 00007fbb1b79c819
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fbb1ba15fac
RBP: 00007fbb1ba15fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbb1ba16038 R14: 00007ffd76843e70 R15: 00007ffd76843f58
rcu: rcu_preempt kthread starved for 10502 jiffies! g170201 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:26880 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
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: 6384 Comm: kworker/u8:12 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfd4/0x13d0 kernel/smp.c:892
Code: 89 ee 83 e6 01 31 ff e8 fa fc 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 a5 f8 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 8a f8 0b 00 eb e5 44 89
RSP: 0018:ffffc9000565f700 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b863c148 RCX: ffff88801db51ec0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000565f840 R08: ffffffff903353f7 R09: 1ffffffff2066a7e
R10: dffffc0000000000 R11: fffffbfff2066a7f R12: 1ffff110170e8169
R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812521e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c44542e CR3: 000000000e74a000 CR4: 0000000000350ef0
Call Trace:
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+0x5f5/0x1160 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:906
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