rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=31e4/1/0x4000000000000000 softirq=9793/9794 fqs=1 (detected by 1, t=10502 jiffies, g=9881, q=16 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4429 Comm: syz.1.18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__lock_acquire+0xdde/0x7c50 kernel/locking/lockdep.c:-1 Code: 48 8d 3c c5 40 22 ae 90 be 08 00 00 00 e8 aa f8 6d 00 49 b8 00 00 00 00 00 fc ff df 48 0f a3 1d 38 1d 4b 0f 0f 83 da 4c 00 00 44 24 34 00 00 00 00 4d 89 e7 49 8d 9c 24 d0 0a 00 00 48 89 d8 RSP: 0018:ffffc900000078e0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 000000000000005e RCX: ffffffff816304f6 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae2248 RBP: ffffc90000007b30 R08: dffffc0000000000 R09: fffffbfff215c44a R10: fffffbfff215c44a R11: 1ffffffff215c449 R12: ffff88807a555940 R13: ffff88807a556402 R14: ffff88807a556448 R15: ffff88807a556468 FS: 00007f76ca93e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f76ca93df98 CR3: 000000002d7ba000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1751 [inline] __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 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:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc90003537880 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 7412d165651b9600 RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefd20 RBP: ffffc90003537998 R08: dffffc0000000000 R09: fffffbfff215c449 R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000000 R13: 1ffff920006a6f1c R14: 0000000000000246 R15: dffffc0000000000 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] cpus_read_lock+0x3e/0x150 kernel/cpu.c:310 clock_was_set+0x165/0x990 kernel/time/hrtimer.c:981 timekeeping_inject_offset+0x578/0x620 kernel/time/timekeeping.c:1395 do_adjtimex+0x418/0x9b0 kernel/time/timekeeping.c:2444 do_clock_adjtime kernel/time/posix-timers.c:1155 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1167 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1158 [inline] __x64_sys_clock_adjtime+0x1f0/0x2a0 kernel/time/posix-timers.c:1158 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: 0033:0x7f76c9b8eec9 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:00007f76ca93e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f76c9de6090 RCX: 00007f76c9b8eec9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f76c9c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f76c9de6128 R14: 00007f76c9de6090 R15: 00007ffdc0721ff8 rcu: rcu_preempt kthread starved for 10500 jiffies! g9881 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: 4389 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:ffffc90003397800 EFLAGS: 00000293 RAX: ffffffff8175f922 RBX: dffffc0000000000 RCX: ffff88802a2e5940 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003397960 R08: dffffc0000000000 R09: fffffbfff215c449 R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 1ffff110171c85b5 R13: ffff8880b8f3bb80 R14: 0000000000000000 R15: ffff8880b8e42da8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f76ca93ed58 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: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