rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=b304/0/0x1 softirq=25303/25303 fqs=60 rcu: (detected by 1, t=10506 jiffies, g=17357, q=410 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:timerqueue_del+0xc1/0x100 lib/timerqueue.c:60 Code: e8 e4 e8 ac f6 4c 89 f8 49 89 04 24 4c 89 f7 48 89 de e8 e2 6a ff ff 42 80 7c 2d 00 00 74 08 4c 89 f7 e8 c2 e8 ac f6 4d 89 36 <48> 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 b9 e7 ac f6 RSP: 0018:ffffc90000007d08 EFLAGS: 00000046 RAX: 1ffff110170c4f7a RBX: ffff8880b8627bd0 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: ffff8880b8627bd0 RDI: ffff88807db4c348 RBP: 1ffff1100fb69868 R08: ffffffff8fa3a037 R09: 1ffffffff1f47406 R10: dffffc0000000000 R11: fffffbfff1f47407 R12: ffff8880b8627bd8 R13: dffffc0000000000 R14: ffff88807db4c340 R15: 1ffff110170c4f7b FS: 0000000000000000(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003c80 CR3: 000000000df36000 CR4: 0000000000350ef0 Call Trace: __remove_hrtimer kernel/time/hrtimer.c:1121 [inline] __run_hrtimer kernel/time/hrtimer.c:1741 [inline] __hrtimer_run_queues+0x364/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 3e 1d 96 f5 cc cc cc 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 73 07 0e 00 f3 0f 1e fa fb f4 13 1d 96 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2 RAX: 3296bd8a6b60e900 RBX: ffffffff819683f8 RCX: 3296bd8a6b60e900 RDX: 0000000000000001 RSI: ffffffff8d9b9313 RDI: ffffffff8be33980 RBP: ffffffff8de07eb8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3 R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fa3a030 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a20 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:744 start_kernel+0x3a9/0x410 init/main.c:1097 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 rcu: rcu_preempt kthread starved for 10205 jiffies! g17357 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:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 6222 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 56 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 01 5f 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 e5 5e 0b 00 eb e4 44 RSP: 0000:ffffc90003107720 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170c8341 RCX: ffff88801e721e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900031078a0 R08: ffffffff8fa3a037 R09: 1ffffffff1f47406 R10: dffffc0000000000 R11: fffffbfff1f47407 R12: ffff8880b8641a08 R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000 FS: 00007fba46b86880(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005579e062ef28 CR3: 00000000561ad000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline] ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101 wp_page_copy mm/memory.c:3618 [inline] do_wp_page+0x1bc2/0x5800 mm/memory.c:4013 handle_pte_fault mm/memory.c:6068 [inline] __handle_mm_fault+0x1033/0x5440 mm/memory.c:6195 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fba464b5b69 Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe9b594670 EFLAGS: 00010206 RAX: 00007fba465f2260 RBX: 00000000000076f0 RCX: 00005579e062ef00 RDX: 00005579e062ef00 RSI: 00007fba465f2260 RDI: 00005579e062ef00 RBP: 00007fba465f1ac0 R08: 00000000000076f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005579e062a540 R13: 00007fba465f1ac0 R14: 00000000000076f0 R15: 00007fba465f1ac0