rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15485/1:b..l
(detected by 1, t=10502 jiffies, g=91953, q=41 ncpus=2)
task:sed state:R running task stack:23664 pid:15485 ppid:15484 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:find_stack lib/stackdepot.c:305 [inline]
RIP: 0010:__stack_depot_save+0x16c/0x460 lib/stackdepot.c:452
Code: ee bd 12 44 8b 25 08 ee bd 12 41 21 ec 4f 8b 2c e0 4d 85 ed 74 64 44 89 f9 eb 09 4d 8b 6d 00 4d 85 ed 74 56 41 39 6d 08 75 f1 <45> 39 7d 0c 75 eb 31 d2 49 8b 34 d6 49 3b 74 d5 18 75 de 48 ff c2
RSP: 0018:ffffc900055cf5d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000000d
RDX: 00000000d2d0eca9 RSI: 000000001343c5b5 RDI: 0000000000002800
RBP: 00000000191b7e71 R08: ffff88823b400000 R09: 0000000000000001
R10: 000000000f2e4c91 R11: fffffbfff1c3ff7e R12: 00000000000b7e71
R13: ffff88802fdac430 R14: ffffc900055cf680 R15: 000000000000000d
save_stack+0x12f/0x230 mm/page_owner.c:128
__reset_page_owner+0x51/0x1a0 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1486 [inline]
free_pcp_prepare mm/page_alloc.c:1536 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3554
release_pages+0x1fa6/0x2220 mm/swap.c:1035
tlb_batch_pages_flush mm/mmu_gather.c:60 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:255 [inline]
tlb_flush_mmu+0x105/0x220 mm/mmu_gather.c:262
tlb_finish_mmu+0xf5/0x220 mm/mmu_gather.c:394
exit_mmap+0x384/0x960 mm/mmap.c:3262
__mmput+0x118/0x3c0 kernel/fork.c:1205
exit_mm+0x25a/0x360 kernel/exit.c:566
do_exit+0x905/0x2480 kernel/exit.c:868
do_group_exit+0x217/0x2d0 kernel/exit.c:1023
__do_sys_exit_group kernel/exit.c:1034 [inline]
__se_sys_exit_group kernel/exit.c:1032 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1032
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa47b0926c5
RSP: 002b:00007ffc2a650238 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa47b193fe8 RCX: 00007fa47b0926c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa47b192680 R15: 00007fa47b194000
rcu: rcu_preempt kthread starved for 10499 jiffies! g91953 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:26864 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0xea2/0x1290 kernel/smp.c:998
Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 f6 f6 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 82 f3 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 67 f3 0a
RSP: 0018:ffffc90000107800 EFLAGS: 00000293
RAX: ffffffff81779349 RBX: dffffc0000000000 RCX: ffff88813fec3b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000107960 R08: ffffffff90afa247 R09: 1ffffffff215f448
R10: dffffc0000000000 R11: fffffbfff215f449 R12: 1ffff110171c8601
R13: ffff8880b8f3bbc0 R14: 0000000000000000 R15: ffff8880b8e43008
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fc1aff8 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:1574 [inline]
text_poke_bp_batch+0x2b7/0x850 arch/x86/kernel/alternative.c:1774
text_poke_flush arch/x86/kernel/alternative.c:1965 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207
static_key_enable+0x16/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xba/0x470 mm/kfence/core.c:821
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295