rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=22fc/1/0x4000000000000000 softirq=75651/75657 fqs=47 rcu: (detected by 1, t=10502 jiffies, g=94225, q=1032 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22197 Comm: syz-executor.5 Not tainted 6.5.0-rc5-syzkaller-01396-g3e6860ec3a22 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:444 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x47/0xb0 kernel/rcu/tree.c:695 Code: c5 77 7a 48 8d 3c ed 00 3a 3a 8c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 54 48 03 1c ed 00 3a 3a 8c <48> b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48 RSP: 0018:ffffc90000007258 EFLAGS: 00000086 RAX: dffffc0000000000 RBX: ffff8880b9836ce8 RCX: ffffffff816722a5 RDX: 1ffffffff1874740 RSI: ffffffff8ac82120 RDI: ffffffff8c3a3a00 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff1d5850a R10: ffffffff8eac2857 R11: 0000000000000000 R12: ffffffff9238e150 R13: 1ffff92000000e6e R14: ffffffff8a6efc80 R15: ffff88802cb49340 FS: 00007f6b5077a6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002000b038 CR3: 00000000465eb000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4bf/0x680 kernel/locking/lockdep.c:5772 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x70 kernel/locking/spinlock.c:194 debug_object_deactivate lib/debugobjects.c:805 [inline] debug_object_deactivate+0x28b/0x320 lib/debugobjects.c:771 debug_hrtimer_deactivate kernel/time/hrtimer.c:427 [inline] debug_deactivate kernel/time/hrtimer.c:483 [inline] __run_hrtimer kernel/time/hrtimer.c:1656 [inline] __hrtimer_run_queues+0x470/0xc10 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1098 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1115 sysvec_apic_timer_interrupt+0x42/0xc0 arch/x86/kernel/apic/apic.c:1109 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 e6 39 2f f7 48 89 df e8 be b8 2f f7 f7 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f 01 00 00 00 e8 65 5b 21 f7 65 8b 05 46 d1 cb 75 85 c0 74 12 5b RSP: 0018:ffffc900000076c8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff923b32f0 RCX: 1ffffffff1d57ed9 RDX: 0000000000000000 RSI: ffffffff8a6c8140 RDI: ffffffff8ac821a0 RBP: 0000000000000202 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8eac2857 R11: 0000000000000000 R12: 0000000000000006 R13: ffff88802b2d3950 R14: ffffffff8a6e0140 R15: 1ffff92000000ee0 debug_object_activate+0x283/0x490 lib/debugobjects.c:745 debug_rcu_head_queue kernel/rcu/rcu.h:226 [inline] __call_rcu_common.constprop.0+0x2c/0x790 kernel/rcu/tree.c:2634 call_rcu_hurry include/linux/rcupdate.h:117 [inline] dst_release net/core/dst.c:167 [inline] dst_release+0x1b5/0x1e0 net/core/dst.c:164 refdst_drop include/net/dst.h:270 [inline] skb_dst_drop include/net/dst.h:282 [inline] skb_release_head_state+0x254/0x2b0 net/core/skbuff.c:1030 skb_release_all net/core/skbuff.c:1045 [inline] __kfree_skb net/core/skbuff.c:1061 [inline] kfree_skb_reason+0xc1/0x210 net/core/skbuff.c:1097 kfree_skb include/linux/skbuff.h:1234 [inline] __udp4_lib_mcast_deliver net/ipv4/udp.c:2278 [inline] __udp4_lib_rcv+0x2a4d/0x33c0 net/ipv4/udp.c:2414 ip_protocol_deliver_rcu+0x9f/0x480 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2e6/0x520 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip_local_deliver+0x1be/0x540 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:468 [inline] ip_rcv_finish+0x1c4/0x2e0 net/ipv4/ip_input.c:449 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip_rcv+0xc8/0x410 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5520 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5634 process_backlog+0x101/0x6c0 net/core/dev.c:5962 __napi_poll.constprop.0+0xb4/0x530 net/core/dev.c:6524 napi_poll net/core/dev.c:6591 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6724 __do_softirq+0x218/0x965 kernel/softirq.c:553 do_softirq kernel/softirq.c:454 [inline] do_softirq+0xaa/0xe0 kernel/softirq.c:441 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:381 local_bh_enable include/linux/bottom_half.h:33 [inline] netif_rx net/core/dev.c:5106 [inline] netif_rx+0x332/0x420 net/core/dev.c:5095 dev_loopback_xmit+0x222/0x670 net/core/dev.c:3886 ip_mc_finish_output+0x1ca/0x610 net/ipv4/ip_output.c:357 NF_HOOK include/linux/netfilter.h:304 [inline] NF_HOOK include/linux/netfilter.h:298 [inline] ip_mc_output+0x5a3/0x720 net/ipv4/ip_output.c:412 dst_output include/net/dst.h:458 [inline] ip_local_out net/ipv4/ip_output.c:127 [inline] ip_send_skb+0xd3/0x250 net/ipv4/ip_output.c:1486 udp_send_skb+0x731/0x1470 net/ipv4/udp.c:963 udp_sendmsg+0x1de3/0x2a50 net/ipv4/udp.c:1245 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:728 [inline] sock_sendmsg+0xd9/0x180 net/socket.c:751 ____sys_sendmsg+0x2ac/0x940 net/socket.c:2514 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2568 __sys_sendmmsg+0x1a1/0x450 net/socket.c:2654 __do_sys_sendmmsg net/socket.c:2683 [inline] __se_sys_sendmmsg net/socket.c:2680 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6b4fa7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6b5077a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f6b4fb9bf80 RCX: 00007f6b4fa7cae9 RDX: 0000000000000300 RSI: 0000000020002080 RDI: 0000000000000004 RBP: 00007f6b4fac847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f6b4fb9bf80 R15: 00007ffdd3453e98 rcu: rcu_preempt kthread starved for 10408 jiffies! g94225 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:28672 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6710 schedule+0xe7/0x1b0 kernel/sched/core.c:6786 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1808 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 22218 Comm: syz-executor.1 Not tainted 6.5.0-rc5-syzkaller-01396-g3e6860ec3a22 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:csd_lock_wait kernel/smp.c:296 [inline] RIP: 0010:smp_call_function_many_cond+0x4db/0x1570 kernel/smp.c:835 Code: 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 1c 5f 0b 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 3c 0e 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc90015c1f570 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9844fe0 RCX: 0000000000000000 RDX: ffff88802e1dd940 RSI: ffffffff817ac174 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000094000 R12: ffffed10173089fd R13: 0000000000000001 R14: ffff8880b993d580 R15: ffff8880b9844fe8 FS: 00007f7da8a126c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f936000 CR3: 0000000079b6e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1003 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2001 [inline] text_poke_bp_batch+0x46b/0x780 arch/x86/kernel/alternative.c:2211 text_poke_bp+0x8b/0xb0 arch/x86/kernel/alternative.c:2438 __static_call_transform.constprop.0+0x281/0x4b0 arch/x86/kernel/static_call.c:111 arch_static_call_transform+0x51/0x90 arch/x86/kernel/static_call.c:163 __static_call_update+0xee/0x650 kernel/static_call_inline.c:147 tracepoint_update_call kernel/tracepoint.c:317 [inline] tracepoint_add_func+0xa0a/0xe40 kernel/tracepoint.c:358 tracepoint_probe_register_prio_may_exist+0xbd/0x100 kernel/tracepoint.c:482 tracepoint_probe_register_may_exist include/linux/tracepoint.h:52 [inline] __bpf_probe_register kernel/trace/bpf_trace.c:2339 [inline] bpf_probe_register+0x164/0x1d0 kernel/trace/bpf_trace.c:2345 bpf_raw_tp_link_attach+0x2e5/0x610 kernel/bpf/syscall.c:3626 bpf_raw_tracepoint_open kernel/bpf/syscall.c:3653 [inline] __sys_bpf+0x31a/0x4ec0 kernel/bpf/syscall.c:5387 __do_sys_bpf kernel/bpf/syscall.c:5449 [inline] __se_sys_bpf kernel/bpf/syscall.c:5447 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5447 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7da7c7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7da8a120c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f7da7d9bf80 RCX: 00007f7da7c7cae9 RDX: 0000000000000029 RSI: 0000000020000180 RDI: 0000000000000011 RBP: 00007f7da7cc847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7da7d9bf80 R15: 00007ffcf2d1ef28