rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=fd0c/1/0x4000000000000000 softirq=15185/15185 fqs=2 (detected by 1, t=10506 jiffies, g=17357, q=41 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5384 Comm: syz.2.253 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:125 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline] RIP: 0010:lock_release+0x575/0x910 kernel/locking/lockdep.c:5685 Code: 21 c7 b2 08 b8 ff ff ff ff 65 0f c1 05 d4 08 9f 7e 83 f8 01 75 75 48 c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 84 24 81 00 00 00 02 75 75 f7 44 24 50 00 02 00 00 74 01 fb 48 RSP: 0018:ffffc90000007b40 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 4b21b045db16ba9e RCX: e1e19aefafde6000 RDX: 0000000000000002 RSI: ffffffff8a8c15e0 RDI: ffffffff8adef320 RBP: ffffc90000007c50 R08: dffffc0000000000 R09: fffffbfff1c3e976 R10: fffffbfff1c3e976 R11: 1ffffffff1c3e975 R12: ffff8880246dc6b0 R13: dffffc0000000000 R14: ffff8880246dc650 R15: 1ffff92000000f74 FS: 00007f731c4cf6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3ce03e CR3: 000000001fb01000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x6d/0x100 kernel/locking/spinlock.c:194 debug_hrtimer_deactivate kernel/time/hrtimer.c:453 [inline] debug_deactivate+0x29/0x240 kernel/time/hrtimer.c:509 __run_hrtimer kernel/time/hrtimer.c:1720 [inline] __hrtimer_run_queues+0x2df/0xd60 kernel/time/hrtimer.c:1816 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194 Code: 74 05 e8 2e e9 66 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b6 74 37 f7 65 8b 05 87 35 e2 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900033b7b80 EFLAGS: 00000206 RAX: e1e19aefafde6000 RBX: 0000000000000a02 RCX: e1e19aefafde6000 RDX: dffffc0000000000 RSI: ffffffff8a8c0460 RDI: 0000000000000001 RBP: ffffc900033b7c10 R08: dffffc0000000000 R09: fffffbfff215ba49 R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: dffffc0000000000 R13: ffff8880b8e2a580 R14: ffff8880b8e2a580 R15: 1ffff92000676f70 clock_was_set+0x189/0x990 kernel/time/hrtimer.c:996 do_settimeofday64+0x575/0x720 kernel/time/timekeeping.c:1345 __do_sys_clock_settime kernel/time/posix-timers.c:1125 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline] __x64_sys_clock_settime+0x223/0x270 kernel/time/posix-timers.c:1113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f731b58ebe9 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:00007f731c4cf038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f731b7b5fa0 RCX: 00007f731b58ebe9 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f731b611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f731b7b6038 R14: 00007f731b7b5fa0 R15: 00007ffe47a36a38 rcu: rcu_preempt kthread starved for 10495 jiffies! g17357 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:27840 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 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: 5258 Comm: kworker/u4:17 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998 Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 5d d9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 e9 d5 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 ce d5 0a RSP: 0018:ffffc900055c7800 EFLAGS: 00000293 RAX: ffffffff8175f112 RBX: dffffc0000000000 RCX: ffff88802ad2bb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900055c7960 R08: dffffc0000000000 R09: fffffbfff215ba49 R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: 1ffff110171c85ad R13: ffff8880b8f3bb40 R14: 0000000000000000 R15: ffff8880b8e42d68 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c38b68a CR3: 000000000c88e000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b0/0x7d0 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+0xb4/0x430 mm/kfence/core.c:805 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295