rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=f5b4/1/0x4000000000000000 softirq=55205/55206 fqs=1 (detected by 0, t=10505 jiffies, g=81849, q=32 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8202 Comm: kworker/u4:18 Not tainted 6.1.134-syzkaller #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:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:mark_lock+0xa2/0x340 kernel/locking/lockdep.c:4606 Code: 00 8b 1b 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 60 82 2b 91 be 08 00 00 00 e8 d6 d6 76 00 48 0f a3 1d 8e ab c0 0f <73> 11 48 8d 04 5b 48 c1 e0 06 48 8d 98 20 01 c4 90 eb 23 48 c7 c0 RSP: 0018:ffffc900001e09b8 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816ad6ca RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff912b8260 RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff225704d R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802c7de418 R13: dffffc0000000000 R14: 0000000000000100 R15: ffff88802c7de4e8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c36e9de CR3: 00000000491e6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4549 [inline] __lock_acquire+0xc6a/0x1f80 kernel/locking/lockdep.c:5003 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x63/0x380 lib/debugobjects.c:753 debug_hrtimer_deactivate kernel/time/hrtimer.c:416 [inline] debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:472 __run_hrtimer kernel/time/hrtimer.c:1659 [inline] __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:49 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline] RIP: 0010:unwind_next_frame+0x4c3/0x2220 arch/x86/kernel/unwind_orc.c:448 Code: 00 00 fc ff df 0f b6 04 08 84 c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 4c 39 e8 4c 0f 46 f9 48 8d 43 fc 48 0f 47 e8 4c 0f 46 e3 <49> 39 ef 76 a9 e9 a7 fd ff ff 89 d9 80 e1 07 80 c1 03 38 c1 7c cd RSP: 0018:ffffc9000361f5c0 EFLAGS: 00000202 RAX: ffffffff8eb76e2c RBX: ffffffff8eb76e30 RCX: ffffffff8eb76e34 RDX: ffffffff8f27da54 RSI: ffffffff81e17fbb RDI: dffffc0000000000 RBP: ffffffff8eb76e2c R08: 0000000000000011 R09: ffffc9000361f790 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8eb76e28 R13: ffffffff81e17fba R14: ffffffff8eb76e08 R15: ffffffff8eb76e2c arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443 __alloc_skb+0xd3/0x2c0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x24c/0xab0 drivers/net/netdevsim/dev.c:851 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10500 jiffies! g81849 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:26200 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 4361 Comm: kworker/u4:10 Not tainted 6.1.134-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1fae/0x3460 kernel/smp.c:998 Code: 2f 44 89 ee 83 e6 01 31 ff e8 6e 47 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 f9 43 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc9000485f5a0 EFLAGS: 00000293 RAX: ffffffff817f08c9 RBX: 1ffff110171e81a1 RCX: ffff888028ecbb80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000485f980 R08: ffffffff817f0892 R09: fffffbfff225704d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8f40d08 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c301e73 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1334 [inline] text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:805 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295