rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=6a54/1/0x4000000000000000 softirq=32482/32483 fqs=18 rcu: (detected by 1, t=10502 jiffies, g=41993, q=1185 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5078 Comm: syz-fuzzer Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:696 Code: 4c 89 f6 e8 52 ce 6c 03 e9 2b ff ff ff e8 58 da 03 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 65 ff 05 18 71 87 7e e8 8b f8 03 0a 89 RSP: 0018:ffffc90000006a18 EFLAGS: 00000002 RAX: 0000000000010100 RBX: 0000000000000001 RCX: ffffffff818392ca RDX: ffff888028408000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000006b80 R08: ffffffff818392f0 R09: 1ffffffff1f51f35 R10: dffffc0000000000 R11: fffffbfff1f51f36 R12: 1ffff1101728593b R13: 0000000000000001 R14: ffff888029ebc340 R15: 0000000000000001 FS: 000000c00005a890(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000425788 CR3: 0000000011382000 CR4: 0000000000350ef0 Call Trace: trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline] __run_hrtimer kernel/time/hrtimer.c:1695 [inline] __hrtimer_run_queues+0x63a/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x13b/0x190 Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90000006d98 EFLAGS: 00000206 RAX: 5e6d78893cc2ff00 RBX: 0000000000000001 RCX: 0000000080000100 RDX: ffff888028408000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1f7ea0 RBP: 0000000000000001 R08: ffffffff895b63a3 R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: 0000000000000246 R13: ffff888028408000 R14: 00000000ffffffff R15: ffffffff8e334da0 sk_filter_trim_cap+0x28c/0xa70 net/core/filter.c:152 tcp_filter net/ipv4/tcp_ipv4.c:2126 [inline] tcp_v4_rcv+0x2b96/0x3780 net/ipv4/tcp_ipv4.c:2311 ip_protocol_deliver_rcu+0x225/0x430 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x33f/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a6/0x450 include/linux/netfilter.h:314 ip_local_deliver net/ipv4/ip_input.c:254 [inline] dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish+0x3be/0x4f0 net/ipv4/ip_input.c:580 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0x75d/0xab0 net/ipv4/ip_input.c:639 ip_list_rcv+0x42b/0x480 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5587 [inline] __netif_receive_skb_list_core+0x95a/0x980 net/core/dev.c:5635 __netif_receive_skb_list net/core/dev.c:5687 [inline] netif_receive_skb_list_internal+0xa51/0xe30 net/core/dev.c:5779 gro_normal_list include/net/gro.h:438 [inline] napi_complete_done+0x310/0x8e0 net/core/dev.c:6119 virtqueue_napi_complete drivers/net/virtio_net.c:515 [inline] virtnet_poll+0xf14/0x1ad0 drivers/net/virtio_net.c:2227 __napi_poll+0xcd/0x490 net/core/dev.c:6638 napi_poll net/core/dev.c:6707 [inline] net_rx_action+0x7bb/0x1090 net/core/dev.c:6822 __do_softirq+0x2c8/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 common_interrupt+0xaa/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 6a 21 88 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000468efc0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920008d1e04 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1f7ea0 RBP: ffffc9000468f108 R08: ffffffff92f35507 R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: 1ffff920008d1e00 R13: dffffc0000000000 R14: ffffc9000468f020 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] nf_hook+0xbf/0x450 include/linux/netfilter.h:238 __ip_local_out+0x3d9/0x4e0 net/ipv4/ip_output.c:118 ip_local_out net/ipv4/ip_output.c:127 [inline] __ip_queue_xmit+0x1162/0x1b70 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2557/0x3b80 net/ipv4/tcp_output.c:1462 tcp_transmit_skb net/ipv4/tcp_output.c:1480 [inline] tcp_write_xmit+0x1445/0x6100 net/ipv4/tcp_output.c:2792 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:2977 tcp_sendmsg_locked+0x42cc/0x4d00 net/ipv4/tcp.c:1310 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1342 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 sock_write_iter+0x2dd/0x400 net/socket.c:1160 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa86/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c0008b8d98 EFLAGS: 00000206 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000040720e RDX: 00000000000000f0 RSI: 000000c000490200 RDI: 0000000000000003 RBP: 000000c0008b8dd8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000c0008b8f18 R13: 0000000000000001 R14: 000000c0000061a0 R15: 000000000000000f rcu: rcu_preempt kthread starved for 10464 jiffies! g41993 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:26256 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/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: CPU: 1 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 0b 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 a4 d6 0b 00 eb e4 44 RSP: 0018:ffffc900001076e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff11017288c6d RCX: ffff888016eebc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001078e0 R08: ffffffff818a38fb R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: dffffc0000000000 R13: ffff8880b9446368 R14: ffff8880b953f7c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc6237b978 CR3: 000000000e134000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 text_poke_bp_batch+0x9ef/0xb30 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244