rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=61dc/1/0x4000000000000000 softirq=59647/59647 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=76373, q=459 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12071 Comm: syz.9.1423 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_acquire+0xc0/0x350 kernel/locking/lockdep.c:5864 Code: ca 11 85 c0 0f 85 bf 00 00 00 65 48 8b 05 00 3c ca 11 83 b8 9c 0b 00 00 00 0f 85 aa 00 00 00 4c 89 74 24 10 4d 89 fe 9c 41 5f 48 c7 c7 cd 44 24 8e e8 f3 5e 2c 0a 65 ff 05 bc 80 ca 11 45 31 RSP: 0018:ffffc90000007d28 EFLAGS: 00000046 RAX: ffff888027e78000 RBX: 0000000000000000 RCX: 0000000000010003 RDX: 0000000000000000 RSI: ffffffff8bd11c4d RDI: 1ffff110170c503b RBP: ffffffff81b31106 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff20aedbf R12: 0000000000000000 R13: ffff8880b86281d8 R14: 0000000000000001 R15: 0000000000000046 FS: 00007f990246f6c0(0000) GS:ffff888124f5a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f990246eff8 CR3: 000000007d110000 CR4: 0000000000350ef0 Call Trace: __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:174 __run_hrtimer kernel/time/hrtimer.c:2036 [inline] __hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 4d ac d1 f5 f7 c3 00 02 00 00 74 05 e8 10 91 fd f5 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 54 c2 c2 f5 65 8b 05 ad 42 9b 07 85 c0 74 18 5b 41 5e e9 7c 23 RSP: 0018:ffffc90004c9faa8 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000246 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8e229adb RDI: 0000000000000001 RBP: ffffc90004c9fbd0 R08: ffffffff90576df7 R09: 1ffffffff20aedbe R10: dffffc0000000000 R11: fffffbfff20aedbf R12: dffffc0000000000 R13: 0000000000000005 R14: ffffffff9a7bf9d8 R15: 1ffff92000993f64 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:573 [inline] __do_adjtimex+0xb2c/0xe40 kernel/time/timekeeping.c:2985 do_adjtimex+0xd1/0x370 kernel/time/timekeeping.c:2996 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1181 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1172 [inline] __x64_sys_clock_adjtime+0x252/0x340 kernel/time/posix-timers.c:1172 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f990159de59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f990246f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f9901825fa0 RCX: 00007f990159de59 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007f9901633e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9901826038 R14: 00007f9901825fa0 R15: 00007ffd66314b78 rcu: rcu_preempt kthread starved for 10500 jiffies! g76373 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 11618 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_single+0x39d/0x5a0 kernel/smp.c:702 Code: 45 8b 27 44 89 e6 83 e6 01 31 ff e8 6d 38 0c 00 41 83 e4 01 75 11 e8 22 34 0c 00 4d 89 ec eb 41 e8 18 34 0c 00 eb 3a 4d 89 ec 90 42 0f b6 04 33 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 fa RSP: 0018:ffffc900026af580 EFLAGS: 00000293 RAX: ffffffff81ba3e46 RBX: 1ffff920004d5ebd RCX: ffff88807a415d00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900026af670 R08: ffffffff90576df7 R09: 1ffffffff20aedbe R10: dffffc0000000000 R11: ffffffff81746150 R12: 1ffff920004d5eb8 R13: 1ffff920004d5eb8 R14: dffffc0000000000 R15: ffffc900026af5e8 FS: 00005555883b7500(0000) GS:ffff88812505a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9901827dac CR3: 000000003dc74000 CR4: 0000000000350ef0 Call Trace: rcu_barrier+0x322/0x530 kernel/rcu/tree.c:3909 netdev_run_todo+0x2ff/0x10d0 net/core/dev.c:11711 nsim_destroy+0x42b/0x800 drivers/net/netdevsim/netdev.c:1203 __nsim_dev_port_del+0x14e/0x200 drivers/net/netdevsim/dev.c:1547 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1561 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1785 nsim_drv_remove+0x58/0x170 drivers/net/netdevsim/dev.c:1800 device_remove drivers/base/dd.c:616 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372 bus_remove_device+0x444/0x560 drivers/base/bus.c:664 device_del+0x524/0x8f0 drivers/base/core.c:3961 device_unregister+0x21/0xf0 drivers/base/core.c:4002 nsim_bus_dev_del drivers/net/netdevsim/bus.c:491 [inline] del_device_store+0x2b5/0x370 drivers/net/netdevsim/bus.c:244 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f605a55e68e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffeb9e41248 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00005555883b7500 RCX: 00007f605a55e68e RDX: 0000000000000001 RSI: 00007ffeb9e412d0 RDI: 0000000000000005 RBP: 00007f605a6346f2 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffeb9e412d0 R14: 00007f605b354620 R15: 0000000000000003