rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l rcu: (detected by 1, t=10503 jiffies, g=54477, q=1598190 ncpus=2) task:kthreadd state:R running task stack:25680 pid:2 tgid:2 ppid:0 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0xed6/0x5920 kernel/sched/core.c:6675 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6997 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x3e5/0x6f0 kernel/locking/lockdep.c:5830 Code: 7e 83 f8 01 0f 85 fd 01 00 00 9c 58 f6 c4 02 0f 85 e8 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 c7 43 08 00 00 00 00 48 8b 84 24 88 RSP: 0018:ffffc90000077730 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200000eee8 RCX: ffffc90000077780 RDX: 1ffff1100385b51a RSI: ffffffff8b6ccf40 RDI: ffffffff8bd196e0 RBP: c4ba6d2bc52afeaa R08: 0000000000000000 R09: fffffbfff20be2b1 R10: ffffffff905f158f R11: 0000000000000050 R12: 0000000000000001 R13: 0000000000000002 R14: ffff88801c2da8d8 R15: ffff88801c2d9e00 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] page_ext_put+0x43/0xd0 mm/page_ext.c:550 __reset_page_owner+0x28d/0x400 mm/page_owner.c:300 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638 __put_partials+0x14c/0x170 mm/slub.c:3146 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4142 copy_signal+0x50/0x830 kernel/fork.c:1844 copy_process+0x275c/0x8dc0 kernel/fork.c:2372 kernel_clone+0xfd/0x960 kernel/fork.c:2787 kernel_thread+0xc0/0x100 kernel/fork.c:2849 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x4ef/0x7d0 kernel/kthread.c:765 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10530 jiffies! g54477 f0x2 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:27392 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0xed6/0x5920 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6767 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5280 Comm: kworker/0:7 Not tainted 6.11.0-syzkaller-11624-ge477dba5442c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:in_softirq_really kernel/kcov.c:171 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data+0x24/0x90 kernel/kcov.c:246 Code: 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 6f e9 76 7e 65 8b 05 70 e9 76 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 1c 16 00 00 85 c0 RSP: 0018:ffffc900000079f8 EFLAGS: 00000202 RAX: 0000000080000102 RBX: 0000000000000002 RCX: ffffffff893cf3d2 RDX: ffff88802fda3c00 RSI: 0000000000000001 RDI: 0000000000000005 RBP: ffffffff8ca25040 R08: 0000000000000005 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000005 R14: 0000000000000004 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2b0a5f CR3: 000000000df7c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:351 nf_hook_slow+0xd2/0x200 net/netfilter/core.c:627 nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269 NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5662 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5775 process_backlog+0x443/0x15f0 net/core/dev.c:6107 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6962 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 do_softirq kernel/softirq.c:455 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:442 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x870/0xc80 drivers/net/netdevsim/dev.c:850 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244