rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=b1ec/1/0x4000000000000000 softirq=17000/17047 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=14373, q=522 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5845 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:advance_sched+0x455/0xd20 net/sched/sch_taprio.c:967 Code: 00 00 48 8b 44 24 18 49 8b 1e 80 38 00 0f 85 20 07 00 00 48 8b 44 24 10 48 89 df 48 8b a8 30 01 00 00 48 89 ee e8 2b 03 42 f8 <48> 39 eb 0f 85 30 ff ff ff e8 3d 09 42 f8 49 83 fd 10 0f 83 5d 07 RSP: 0018:ffffc90000007de8 EFLAGS: 00000046 RAX: 0000000000010001 RBX: 00000000000003e8 RCX: ffffffff89c856f5 RDX: 00000000000003e8 RSI: 00000000000003e8 RDI: ffff888036dd2540 RBP: 00000000000003e8 R08: 0000000000000006 R09: 00000000000003e8 R10: 00000000000003e8 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888079c17400 R15: 0000000000000001 FS: 00007fdc6aa6a780(0000) GS:ffff888123ddc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdc6abf6fb3 CR3: 000000007550d000 CR4: 00000000003526f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 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:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 fb 4d 7e 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 86 81 3c 0f 0f 82 ac 02 00 00 8b 35 4e b5 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 9d 4d 7e 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc90002e2f7c0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 943904b7742d9bd4 RDX: 0000000000000000 RSI: ffffffff8e17fc5f RDI: ffffffff8c401580 RBP: ffff88807e28f1c8 R08: 000000000b2d5154 R09: 00000000000005c2 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 __vma_start_exclude_readers+0x2b4/0x810 mm/mmap_lock.c:125 __vma_start_write+0x11c/0x280 mm/mmap_lock.c:148 vma_start_write include/linux/mmap_lock.h:303 [inline] vma_start_write include/linux/mmap_lock.h:298 [inline] vms_gather_munmap_vmas+0x490/0x1720 mm/vma.c:1452 do_vmi_align_munmap+0x287/0x5f0 mm/vma.c:1595 do_vmi_munmap+0x1f8/0x3e0 mm/vma.c:1652 __vm_munmap+0x196/0x390 mm/vma.c:3288 __do_sys_munmap mm/mmap.c:1079 [inline] __se_sys_munmap mm/mmap.c:1076 [inline] __x64_sys_munmap+0x59/0x80 mm/mmap.c:1076 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdc6ac792e7 Code: 00 00 00 b8 0a 00 00 00 0f 05 48 3d 01 f0 ff ff 73 01 c3 48 8d 0d c9 3f 01 00 f7 d8 89 01 48 83 c8 ff c3 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d a9 3f 01 00 f7 d8 89 01 48 83 RSP: 002b:00007fff01c13008 EFLAGS: 00000202 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000555756208e50 RCX: 00007fdc6ac792e7 RDX: 0000000000000001 RSI: 000000000002f6d0 RDI: 00007fdc6aa0b000 RBP: 00007fff01c13110 R08: 00000000000004f0 R09: 0000000000000002 R10: 00007fff01c12f40 R11: 0000000000000202 R12: 00007fff01c13050 R13: 00007fdc6ac8c000 R14: 0000555756208e50 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g14373 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=3031 rcu: rcu_preempt kthread starved for 10496 jiffies! g14373 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245