rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14694/1:b..l P14721/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=83761, q=843 ncpus=2)
task:syz.5.2304 state:R running task stack:26104 pid:14721 tgid:14720 ppid:7273 task_flags:0x40054c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
zap_pte_range mm/memory.c:1964 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x16f7/0x4a30 mm/memory.c:2109
unmap_vmas+0x299/0x5f0 mm/memory.c:2178
exit_mmap+0x1ef/0xa00 mm/mmap.c:1300
__mmput+0x12a/0x410 kernel/fork.c:1187
mmput+0x67/0x80 kernel/fork.c:1210
exit_mm kernel/exit.c:615 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:997
do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__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:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b2f79de99
RSP: 002b:00007f1b306330e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f1b2fa25fa8 RCX: 00007f1b2f79de99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1b2fa25fa8
RBP: 00007f1b2fa25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b2fa26038 R14: 00007ffc0c713c90 R15: 00007ffc0c713d78
task:syz.4.2300 state:R running task stack:25784 pid:14694 tgid:14691 ppid:5609 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0xa00 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213
Code: 64 00 be 03 00 00 00 5b e9 92 84 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 85 a3 59 12 <48> 8b 34 24 65 48 8b 15 61 a3 59 12 a9 00 01 ff 00 74 1b f6 c4 01
RSP: 0018:ffffc90005637498 EFLAGS: 00000286
RAX: 0000000080000000 RBX: ffff88805616d342 RCX: ffffffff8bb76b88
RDX: ffff88805616d342 RSI: 0000000000001000 RDI: ffff888045e52540
RBP: 0000000000000002 R08: 0000000000000007 R09: 0000000000001000
R10: ffff88805616d342 R11: 0000000000000000 R12: ffffc90005637500
R13: ffffc90005637500 R14: ffff88807ed9cc80 R15: 0000000000000851
xa_to_node include/linux/xarray.h:1264 [inline]
xas_load+0x76/0x5c0 lib/xarray.c:242
filemap_get_entry+0x115/0x450 mm/filemap.c:1901
shmem_get_folio_gfp+0x221/0x1910 mm/shmem.c:2426
shmem_fault+0x1f9/0xa20 mm/shmem.c:2703
__do_fault+0x10b/0x440 mm/memory.c:5425
do_read_fault mm/memory.c:5860 [inline]
do_fault+0xa99/0x1750 mm/memory.c:5994
do_pte_missing mm/memory.c:4566 [inline]
handle_pte_fault mm/memory.c:6379 [inline]
__handle_mm_fault+0x187d/0x2a00 mm/memory.c:6517
handle_mm_fault+0x37b/0xa30 mm/memory.c:6686
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x1178/0x32a0 mm/gup.c:1428
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
__mm_populate+0x107/0x3a0 mm/gup.c:1963
mm_populate include/linux/mm.h:4171 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:586
ksys_mmap_pgoff+0xe4/0x610 mm/mmap.c:606
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe7c5f9de99
RSP: 002b:00007fe7c6ddd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fe7c6225fa0 RCX: 00007fe7c5f9de99
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fe7c6033eaf R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7c6226038 R14: 00007fe7c6225fa0 R15: 00007ffc2a961c18
rcu: rcu_preempt kthread starved for 10492 jiffies! g83761 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
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: 0 UID: 0 PID: 170 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 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 c9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31
RSP: 0018:ffffc9000200f878 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fd46fd
RDX: ffff88801df6a540 RSI: ffffffff81fd46d7 RDI: ffff88801df6a540
RBP: ffff8880b8541240 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a8249 R14: 0000000000000001 R15: ffff8880b843c880
FS: 0000000000000000(0000) GS:ffff888123de8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf7ddac890 CR3: 000000000e992000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 000000000000000e
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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:911 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:903
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
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