rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=d6b4/1/0x4000000000000000 softirq=114584/114584 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P25788/1:b..l rcu: (detected by 0, t=10506 jiffies, g=119169, q=204 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25789 Comm: syz.8.7560 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:kasan_check_range+0x5/0x2c0 mm/kasan/generic.c:199 Code: eb ec 90 0f 0b 90 b8 ea ff ff ff eb e1 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 <41> 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ba 01 00 00 4c 8d RSP: 0018:ffffc90000a08bf0 EFLAGS: 00000046 RAX: 1ffff1100a6fae80 RBX: 0000000000000000 RCX: ffffffff89604263 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880285632e0 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014117c R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880285632e0 R15: ffff8880537d7400 FS: 000055555e733500(0000) GS:ffff888126239000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3b4065 CR3: 000000007bff6000 CR4: 0000000000350ef0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic64_read include/linux/atomic/atomic-instrumented.h:1610 [inline] taprio_set_budgets+0x1e3/0x3b0 net/sched/sch_taprio.c:675 advance_sched+0x963/0xc90 net/sched/sch_taprio.c:982 __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:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5193 Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 3f 2d b8 09 e8 7a b9 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 58 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90000bd77b8 EFLAGS: 00000286 RAX: 04fe95b86c5e1900 RBX: 0000000000000000 RCX: 04fe95b86c5e1900 RDX: 0000000000000000 RSI: ffffffff8d70e869 RDI: ffffffff8bbf08e0 RBP: ffffc90000bd7810 R08: ffffffff8f7cef77 R09: 1ffffffff1ef9dee R10: dffffc0000000000 R11: fffffbfff1ef9def R12: ffff88802f960000 R13: dffffc0000000000 R14: ffff888079a05ac0 R15: ffff8880b893abd8 context_switch kernel/sched/core.c:5328 [inline] __schedule+0x17a0/0x4cc0 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 class_preempt_destructor include/linux/preempt.h:470 [inline] try_to_wake_up+0x82b/0x12b0 kernel/sched/core.c:4300 wake_up_process kernel/sched/core.c:4424 [inline] wake_up_q+0x85/0xd0 kernel/sched/core.c:1086 futex_wake+0x4a0/0x560 kernel/futex/waitwake.c:198 do_futex+0x395/0x420 kernel/futex/syscalls.c:135 __do_sys_futex kernel/futex/syscalls.c:207 [inline] __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188 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: 0033:0x7f8e78d8f749 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:00007ffdc5d3aaa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f8e78fe5fa8 RCX: 00007f8e78d8f749 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f8e78fe5fa8 RBP: 0000000000000000 R08: 0000000000000024 R09: 00000004c5d3ad9f R10: 00007f8e78fe5fa0 R11: 0000000000000246 R12: 00007f8e78fe5fac R13: 00007f8e78fe5fa0 R14: 00000000000000e8 R15: 0000000000000002 task:syz.3.7559 state:R running task stack:26888 pid:25788 tgid:25785 ppid:23209 task_flags:0x40044c 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] zap_pte_range mm/memory.c:1885 [inline] zap_pmd_range mm/memory.c:1947 [inline] zap_pud_range mm/memory.c:1976 [inline] zap_p4d_range mm/memory.c:1997 [inline] unmap_page_range+0x3a7f/0x4370 mm/memory.c:2018 unmap_single_vma mm/memory.c:2061 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2105 exit_mmap+0x240/0xb40 mm/mmap.c:1280 __mmput+0x118/0x430 kernel/fork.c:1133 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:954 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdd65b8f749 RSP: 002b:00007fdd669750e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fdd65de5fa8 RCX: 00007fdd65b8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdd65de5fa8 RBP: 00007fdd65de5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdd65de6038 R14: 00007ffec925aef0 R15: 00007ffec925afd8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g119169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=58556 rcu: rcu_preempt kthread starved for 10506 jiffies! g119169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I 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