rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=b494/1/0x4000000000000000 softirq=61194/61194 fqs=0 rcu: (detected by 0, t=10505 jiffies, g=65901, q=294 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12116 Comm: syz.5.1570 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:check_region_inline mm/kasan/generic.c:183 [inline] RIP: 0010:kasan_check_range+0xf6/0x1e0 mm/kasan/generic.c:200 Code: 00 00 00 00 48 83 c0 01 48 39 c2 74 1d 80 38 00 74 f2 ba 01 00 00 00 48 85 c0 74 2c 41 83 e2 07 49 39 c1 75 15 45 3a 11 7d 10 01 00 00 00 5b 5d 89 d0 41 5c c3 cc cc cc cc 41 0f b6 d0 e8 e1 RSP: 0018:ffffc90000a18d28 EFLAGS: 00000046 RAX: ffffed100465d456 RBX: ffffed100465d456 RCX: ffffffff81e76789 RDX: ffffed100465d456 RSI: 0000000000000004 RDI: ffff8880232ea2a8 RBP: ffffed100465d455 R08: 0000000000000001 R09: ffffed100465d455 R10: ffff8880232ea2ab R11: 0000000000000000 R12: 1ffff920001431aa R13: ffff8880232ea2b8 R14: ffff8880b8528640 R15: ffff8880b8528690 FS: 00007f89c8ad16c0(0000) GS:ffff888123c64000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d1daff8 CR3: 00000000740fa000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:112 [inline] do_raw_spin_lock+0x119/0x260 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:347 [inline] advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:931 __run_hrtimer kernel/time/hrtimer.c:2067 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2124 hrtimer_interrupt+0x441/0xaa0 kernel/time/hrtimer.c:2243 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/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_irq_enable include/linux/spinlock_api_smp.h:229 [inline] RIP: 0010:_raw_spin_unlock_irq_enable+0x4c/0x90 kernel/locking/spinlock.c:237 Code: 00 ff ff 65 48 0f c1 05 1a b6 b9 08 48 2d 00 00 01 00 a9 00 00 ff 00 75 11 65 f6 05 06 f8 b9 08 02 75 22 9c 58 f6 c4 02 75 35 01 00 00 00 e8 9a 68 04 f6 65 48 83 3d e9 b5 b9 08 00 74 15 5b RSP: 0018:ffffc9000d5a7b40 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff9b997438 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff8e3eaa9f RDI: ffffffff8c620c80 RBP: ffffc9000d5a7c48 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000004 R12: ffffffff9b997180 R13: 0000000000000000 R14: ffffc9000d5a7c88 R15: ffffffff9b99736c class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:594 [inline] __do_adjtimex+0x8d5/0xe50 kernel/time/timekeeping.c:3004 do_adjtimex+0xa0/0x370 kernel/time/timekeeping.c:3047 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime+0x177/0x290 kernel/time/posix-timers.c:1181 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f89c7b9e159 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:00007f89c8ad1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f89c7e26090 RCX: 00007f89c7b9e159 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 00007f89c7c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f89c7e26128 R14: 00007f89c7e26090 R15: 00007fffbb015c48 rcu: rcu_preempt kthread starved for 10505 jiffies! g65901 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27576 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122 rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 68 9c 02 e9 43 4f 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 96 1c 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8ea07cf0 EFLAGS: 00000246 RAX: 000000000135b9f5 RBX: ffffffff8ea91500 RCX: ffffffff8bcf2115 RDX: 0000000000000001 RSI: ffffffff8e3eaa9f RDI: ffffffff8c620c80 RBP: fffffbfff1d522a0 R08: 0000000000000001 R09: ffffed10170867bd R10: ffff8880b8433deb R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1d40fa2 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123b64000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f906ff8 CR3: 0000000045172000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x2d3/0x2e0 init/main.c:727 start_kernel+0x48e/0x490 init/main.c:1185 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158