rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=01b4/1/0x4000000000000000 softirq=53058/53062 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10591/1:b..l rcu: (detected by 0, t=10502 jiffies, g=43625, q=385 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10589 Comm: syz.7.1047 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_release+0xaa/0x3e0 kernel/locking/lockdep.c:5885 Code: 92 41 83 bf 2c 0b 00 00 00 0f 85 1e 02 00 00 49 81 3e 40 d3 31 93 0f 84 11 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 <48> 8b 5c 24 20 fa 48 c7 c7 9a 02 72 8d e8 84 c8 a8 09 65 ff 05 8d RSP: 0018:ffffc90000a08c08 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffffffff895fe0a8 RCX: d898674e64821900 RDX: 0000000000010000 RSI: ffffffff8bbf05c0 RDI: ffffffff8bbf0580 RBP: 0000000000000001 R08: ffff888143ac415f R09: 1ffff1102875882b R10: dffffc0000000000 R11: ffffed102875882c R12: ffff888143ac4360 R13: ffffffff895fe0a8 R14: ffffffff8df3d2e0 R15: ffff88807b5c8000 FS: 00007fa3fa64b6c0(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555880cb808 CR3: 0000000055037000 CR4: 0000000000350ef0 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:992 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 6f RSP: 0018:ffffc9000c217940 EFLAGS: 00000283 RAX: ffffffff81b4952b RBX: 1ffff11017108441 RCX: 0000000000080000 RDX: ffffc9002019c000 RSI: 00000000000001ad RDI: 00000000000001ae RBP: ffffc9000c217ab0 R08: ffffffff8f7cd477 R09: 1ffffffff1ef9a8e R10: dffffc0000000000 R11: ffffffff8170f180 R12: ffff8880b8842208 R13: dffffc0000000000 R14: ffff8880b893b240 R15: 0000000000000000 clock_was_set+0x709/0x7c0 kernel/time/hrtimer.c:969 do_adjtimex+0x228/0x310 kernel/time/timekeeping.c:2753 do_clock_adjtime kernel/time/posix-timers.c:1161 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1173 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1164 [inline] __x64_sys_clock_adjtime+0x211/0x2c0 kernel/time/posix-timers.c:1164 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa3f978efc9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa3fa64b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007fa3f99e5fa0 RCX: 00007fa3f978efc9 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 00007fa3f9811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa3f99e6038 R14: 00007fa3f99e5fa0 R15: 00007fff1b352d18 task:syz.2.1045 state:R running task stack:25608 pid:10591 tgid:10590 ppid:9967 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] do_anonymous_page mm/memory.c:5239 [inline] do_pte_missing mm/memory.c:4359 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x3a3e/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fb231050ca6 RSP: 002b:00007fb2320244a0 EFLAGS: 00010206 RAX: 0000000000d13001 RBX: 00007fb232024540 RCX: 00000000000000b8 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007fb2320245e0 RBP: 0000000000000102 R08: 00007fb226e00000 R09: 0000000000d13000 R10: 0000000000000000 R11: 00007fb232024550 R12: 0000000000000001 R13: 00007fb23122dc40 R14: 0000000000000000 R15: 00007fb2320245e0 rcu: rcu_preempt kthread starved for 10498 jiffies! g43625 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 5981 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 6f RSP: 0018:ffffc90004e67640 EFLAGS: 00000293 RAX: ffffffff81b4952b RBX: 1ffff11017127ffd RCX: ffff88802cd73c80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004e677c0 R08: ffffffff8f7cd477 R09: 1ffffffff1ef9a8e R10: dffffc0000000000 R11: fffffbfff1ef9a8f R12: ffff8880b893ffe8 R13: dffffc0000000000 R14: ffff8880b883b240 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c181b6358 CR3: 000000000dd38000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2713 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2923 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:857 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245