rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5904/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=14329, q=3836 ncpus=2)
task:syz.0.25 state:R running task stack:27256 pid:5904 tgid:5903 ppid:5752 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_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:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline]
RIP: 0010:__orc_find+0x86/0xf0 arch/x86/kernel/unwind_orc.c:103
Code: f2 48 d1 fa 48 8d 5c 95 00 48 89 da 48 c1 ea 03 0f b6 34 0a 48 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13 <48> 01 da 49 39 d5 73 af 4c 8d 63 fc 49 39 ec 73 b2 4d 29 f7 49 c1
RSP: 0018:ffffc90003817258 EFLAGS: 00000246
RAX: ffffffff91c453f4 RBX: ffffffff913b4ddc RCX: dffffc0000000000
RDX: fffffffff07d3840 RSI: 0000000000000000 RDI: ffffffff913b4dbc
RBP: ffffffff913b4dbc R08: ffffffff91c4545a R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000b886 R12: ffffffff913b4dfc
R13: ffffffff81b88696 R14: ffffffff913b4dbc R15: ffffffff913b4dbc
orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
unwind_next_frame+0x2ec/0x2090 arch/x86/kernel/unwind_orc.c:510
__unwind_start+0x3cd/0x7e0 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kmem_cache_free+0x127/0x6b0 mm/slub.c:6504
anon_vma_chain_free mm/rmap.c:147 [inline]
unlink_anon_vmas+0x4c1/0x8e0 mm/rmap.c:539
free_pgtables+0x2e7/0xd80 mm/memory.c:414
exit_mmap+0x44c/0xa00 mm/mmap.c:1312
__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: 0033:0x7f7f6b19de99
RSP: 002b:00007f7f6bf880e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7f6b425fa8 RCX: 00007f7f6b19de99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7f6b425fa8
RBP: 00007f7f6b425fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7f6b426038 R14: 00007ffca62637d0 R15: 00007ffca62638b8
rcu: rcu_preempt kthread starved for 537 jiffies! g14329 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: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: 1 UID: 0 PID: 70 Comm: kworker/u8:4 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+0x58e/0x1870 kernel/smp.c:912
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 64 99 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 8b 45 08 31
RSP: 0018:ffffc9000202f858 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fdc702
RDX: ffff88801e71ca80 RSI: ffffffff81fdc6dc RDI: ffff88801e71ca80
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 0000000000000000(0000) GS:ffff888123edc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562378102da8 CR3: 000000000e994000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077
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