rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=2bc4/1/0x4000000000000000 softirq=51858/51858 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5832/1:b..l P17562/1:b..l rcu: (detected by 0, t=10503 jiffies, g=51153, q=192 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3521 Comm: kworker/u8:9 Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline] RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] RIP: 0010:_raw_spin_lock_irqsave+0x92/0x120 kernel/locking/spinlock.c:162 Code: 00 4c 89 e3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 e7 e8 d1 2c 23 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 42 80 3c 3b 00 <74> 08 4c 89 e7 e8 c4 2b 23 f6 4c 8b 64 24 20 fa 41 f7 c4 00 02 00 RSP: 0018:ffffc90000a18520 EFLAGS: 00000046 RAX: f3f3f300f1f1f1f1 RBX: 1ffff920001430a8 RCX: 0000000000017278 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff9a8b17e0 RBP: ffffc90000a185b0 R08: ffffc90000a1862f R09: 0000000000000000 R10: ffffc90000a18620 R11: fffff520001430c6 R12: ffffc90000a18540 R13: 1ffff920001430a4 R14: ffffffff9a8b17e0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555555e9808 CR3: 000000000e938000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_activate+0x17f/0x580 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:455 [inline] debug_activate kernel/time/hrtimer.c:496 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1100 __run_hrtimer kernel/time/hrtimer.c:1818 [inline] __hrtimer_run_queues+0x6cb/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pie_calculate_probability+0x5ce/0x820 net/sched/sch_pie.c:421 Code: 00 0f b6 5d 00 31 ff 89 de e8 7e 05 c7 f7 85 db 74 07 e8 75 02 c7 f7 eb 24 e8 6e 02 c7 f7 4c 89 e0 48 c1 e8 03 42 80 3c 30 00 <74> 08 4c 89 e7 e8 28 b6 2b f8 48 8b 44 24 20 49 89 04 24 48 83 c4 RSP: 0018:ffffc90000a18a80 EFLAGS: 00000246 RAX: 1ffff11008d9e339 RBX: 0000000000000000 RCX: ffff888032dc0000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88802a33f31a R08: ffffffff89fab7b2 R09: fffff52000143154 R10: dffffc0000000000 R11: fffff52000143154 R12: ffff888046cf19c8 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888046cf19f8 fq_pie_timer+0x26d/0x590 net/sched/sch_fq_pie.c:400 call_timer_fn+0x187/0x650 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:deref_stack_reg+0x18f/0x210 arch/x86/kernel/unwind_orc.c:406 Code: 31 c0 4c 39 e1 76 33 4c 39 f9 77 2e 4c 89 c7 48 89 d3 e8 f4 07 00 00 49 89 c6 48 8b 6c 24 18 48 89 e8 48 c1 e8 03 80 3c 18 00 <74> 08 48 89 ef e8 17 32 b9 00 4c 89 75 00 b0 01 48 83 c4 20 5b 41 RSP: 0018:ffffc9000ce87438 EFLAGS: 00000246 RAX: 1ffff920019d0eb4 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffc9000ce80000 RDI: ffffc9000ce87988 RBP: ffffc9000ce875a0 R08: ffffc9000ce87988 R09: 0000000000000000 R10: ffffc9000ce875b0 R11: fffff520019d0eb8 R12: 1ffff920019d0ead R13: 1ffff920019d0eae R14: ffff888059cfeec0 R15: ffffc9000ce88000 unwind_next_frame+0x1799/0x22d0 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x196/0x430 mm/slub.c:4757 skb_kfree_head net/core/skbuff.c:996 [inline] skb_free_head net/core/skbuff.c:1008 [inline] skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1035 skb_release_all net/core/skbuff.c:1100 [inline] __kfree_skb net/core/skbuff.c:1114 [inline] consume_skb+0x9f/0xf0 net/core/skbuff.c:1346 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x7cc/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 task:syz.5.3967 state:R running task stack:26104 pid:17562 tgid:17561 ppid:12273 task_flags:0x40054c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1772 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0x3a0d/0x4510 mm/memory.c:1905 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1995 exit_mmap+0x283/0xd40 mm/mmap.c:1284 __mmput+0x115/0x410 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f61dd78d169 RSP: 002b:00007f61de5610e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f61dd9a5fa8 RCX: 00007f61dd78d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f61dd9a5fa8 RBP: 00007f61dd9a5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f61dd9a5fac R13: 0000000000000000 R14: 00007ffe1779bbc0 R15: 00007ffe1779bca8 task:syz-executor state:R running task stack:20064 pid:5832 tgid:5832 ppid:5816 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1201 [inline] copy_pmd_range+0x6ddc/0x77b0 mm/memory.c:1262 copy_pud_range mm/memory.c:1299 [inline] copy_p4d_range mm/memory.c:1323 [inline] copy_page_range+0x99f/0xe90 mm/memory.c:1421 dup_mmap kernel/fork.c:748 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm+0x1269/0x2160 kernel/fork.c:1752 copy_process+0x17d1/0x3cf0 kernel/fork.c:2403 kernel_clone+0x223/0x870 kernel/fork.c:2815 __do_sys_clone kernel/fork.c:2958 [inline] __se_sys_clone kernel/fork.c:2942 [inline] __x64_sys_clone+0x267/0x2e0 kernel/fork.c:2942 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f018c5839d3 RSP: 002b:00007fffd8b1bcc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f018c5839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055557b6777d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000049872 R15: 00007fffd8b1be60 rcu: rcu_preempt kthread starved for 10501 jiffies! g51153 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:25624 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 5820 Comm: syz-executor Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bb6/0x2d30 kernel/smp.c:885 Code: 30 f5 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 e0 f0 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 <41> f7 45 00 01 00 00 00 74 1e e8 bb f0 0b 00 eb db 44 89 e9 80 e1 RSP: 0018:ffffc90003edf500 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff110170e88c9 RCX: ffff8880304abc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003edf700 R08: ffffffff81b5c940 R09: 1ffffffff28a230e R10: dffffc0000000000 R11: fffffbfff28a230f R12: ffff8880b863f9c8 R13: ffff8880b8744648 R14: ffff8880b863f9c0 R15: 0000000000000001 FS: 00005555721ff500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3f12a5 CR3: 000000003083c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054 dup_mmap kernel/fork.c:787 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm+0x18af/0x2160 kernel/fork.c:1752 copy_process+0x17d1/0x3cf0 kernel/fork.c:2403 kernel_clone+0x223/0x870 kernel/fork.c:2815 __do_sys_clone kernel/fork.c:2958 [inline] __se_sys_clone kernel/fork.c:2942 [inline] __x64_sys_clone+0x267/0x2e0 kernel/fork.c:2942 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd8507839d3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffe8a6fccb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd8507839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555721ff7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000498a4 R15: 00007ffe8a6fce50