rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=709c/1/0x4000000000000000 softirq=32798/32798 fqs=0 rcu: (t=10500 jiffies g=42965 q=401 ncpus=2) rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g42965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=38575 rcu: rcu_preempt kthread starved for 10500 jiffies! g42965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28704 pid:15 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 64 Comm: kworker/u4:4 Not tainted 6.4.0-rc4-syzkaller-00031-g8b817fded42d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:236 Code: 01 00 00 49 89 f8 65 48 8b 14 25 00 bc 03 00 a9 00 01 ff 00 74 0e 85 f6 74 59 8b 82 0c 16 00 00 85 c0 74 4f 8b 82 e8 15 00 00 <83> f8 03 75 44 48 8b 82 f0 15 00 00 8b 92 ec 15 00 00 48 8b 38 48 RSP: 0018:ffffc9000206f940 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffe8ffffc02420 RCX: ffffffff817824d3 RDX: ffff888018ec8040 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: fffff91ffff80485 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd8701ad988 CR3: 000000000c571000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:285 [inline] smp_call_function_many_cond+0x6a3/0x15a0 kernel/smp.c:828 on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:996 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1770 [inline] text_poke_bp_batch+0x237/0x770 arch/x86/kernel/alternative.c:1970 text_poke_flush arch/x86/kernel/alternative.c:2161 [inline] text_poke_flush arch/x86/kernel/alternative.c:2158 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:831 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:823 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5025 Comm: syz-fuzzer Not tainted 6.4.0-rc4-syzkaller-00031-g8b817fded42d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x3d/0xb0 kernel/rcu/tree.c:695 Code: c7 c3 e8 6c 03 00 83 f8 07 89 c5 77 7a 48 8d 3c ed 00 ea 12 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 ea 12 8c 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffffc90000006670 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000036ce8 RCX: ffffffff816506d5 RDX: 1ffffffff1825d40 RSI: 0000000000010103 RDI: ffffffff8c12ea00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8e79b797 R10: fffffbfff1cf36f2 R11: 0000000000000000 R12: ffffffff8d0fa6e0 R13: 0000000000000000 R14: 1ffff92000000cee R15: 0000000000000001 FS: 000000c01eb81090(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2da38000 CR3: 000000007d434000 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+0x4fb/0x670 kernel/locking/lockdep.c:5716 debug_objects_fill_pool lib/debugobjects.c:607 [inline] debug_object_activate+0x141/0x4f0 lib/debugobjects.c:704 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xa5b/0xbe0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x44/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200 Code: b6 b3 8e 02 66 0f 1f 44 00 00 f3 0f 1e fa 48 8b be a8 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1e fa 65 8b 05 bd 56 80 7e 89 c1 48 8b 34 24 81 e1 00 01 00 RSP: 0018:ffffc90000006af8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff88801eb9f4a8 RCX: ffffffff88cdfc24 RDX: ffff88807aba4080 RSI: 0000000000000100 RDI: 0000000000000005 RBP: ffffc90000006b70 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000001 R14: 000000000000000d R15: ffff888076c8d000 find_match.part.0+0x25b/0xd80 include/net/addrconf.h:315 find_match net/ipv6/route.c:827 [inline] __find_rr_leaf+0x17f/0xdc0 net/ipv6/route.c:828 find_rr_leaf net/ipv6/route.c:849 [inline] rt6_select net/ipv6/route.c:893 [inline] fib6_table_lookup+0x62e/0xa20 net/ipv6/route.c:2181 ip6_pol_route+0x1c9/0x1230 net/ipv6/route.c:2217 pol_lookup_func include/net/ip6_fib.h:576 [inline] fib6_rule_lookup+0x115/0x6e0 net/ipv6/fib6_rules.c:116 ip6_route_input_lookup net/ipv6/route.c:2286 [inline] ip6_route_input+0x5d8/0xbb0 net/ipv6/route.c:2582 ip6_rcv_finish_core.constprop.0+0x1a4/0x5d0 net/ipv6/ip6_input.c:66 ip6_rcv_finish+0x130/0x2c0 net/ipv6/ip6_input.c:77 ip_sabotage_in+0x22a/0x2a0 net/bridge/br_netfilter_hooks.c:880 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_slow+0xc9/0x1f0 net/netfilter/core.c:626 nf_hook.constprop.0+0x408/0x710 include/linux/netfilter.h:258 NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0xa2/0x380 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5491 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5605 netif_receive_skb_internal net/core/dev.c:5691 [inline] netif_receive_skb+0x133/0x7a0 net/core/dev.c:5750 NF_HOOK include/linux/netfilter.h:303 [inline] NF_HOOK include/linux/netfilter.h:297 [inline] br_pass_frame_up+0x303/0x430 net/bridge/br_input.c:68 br_handle_frame_finish+0xd1f/0x1de0 net/bridge/br_input.c:216 br_nf_hook_thresh+0x2fb/0x3f0 net/bridge/br_netfilter_hooks.c:1048 br_nf_pre_routing_finish_ipv6+0x695/0xf30 net/bridge/br_netfilter_ipv6.c:148 NF_HOOK include/linux/netfilter.h:303 [inline] br_nf_pre_routing_ipv6+0x41b/0x830 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0xda4/0x1520 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x9cb/0x1320 net/bridge/br_input.c:416 __netif_receive_skb_core+0xa10/0x3900 net/core/dev.c:5385 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5489 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5605 process_backlog+0x101/0x670 net/core/dev.c:5933 __napi_poll+0xb7/0x6f0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x8a9/0xcb0 net/core/dev.c:6696 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 do_softirq.part.0+0xde/0x130 kernel/softirq.c:472 do_softirq kernel/softirq.c:464 [inline] __local_bh_enable_ip+0x106/0x130 kernel/softirq.c:396 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline] __dev_queue_xmit+0x1e20/0x3b10 net/core/dev.c:4271 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0x15a1/0x22b0 net/ipv4/ip_output.c:229 __ip_finish_output net/ipv4/ip_output.c:307 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:289 ip_finish_output+0x31/0x280 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip_output+0x1a3/0x320 net/ipv4/ip_output.c:431 dst_output include/net/dst.h:458 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x8d9/0x1c50 net/ipv4/ip_output.c:533 __tcp_transmit_skb+0x194b/0x3800 net/ipv4/tcp_output.c:1399 tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline] tcp_write_xmit+0x1025/0x6160 net/ipv4/tcp_output.c:2693 __tcp_push_pending_frames+0xae/0x390 net/ipv4/tcp_output.c:2877 tcp_push+0x49d/0x720 net/ipv4/tcp.c:733 tcp_sendmsg_locked+0x1ff8/0x2960 net/ipv4/tcp.c:1459 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1487 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0xde/0x190 net/socket.c:747 sock_write_iter+0x295/0x3d0 net/socket.c:1140 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x945/0xd50 fs/read_write.c:584 ksys_write+0x1ec/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x403ace Code: 48 89 6c 24 38 48 8d 6c 24 38 e8 0d 00 00 00 48 8b 6c 24 38 48 83 c4 40 c3 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:000000c000a53120 EFLAGS: 00000206 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000403ace RDX: 00000000000000f0 RSI: 000000c00022c200 RDI: 0000000000000003 RBP: 000000c000a53160 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000c000a532a0 R13: 0000000000000000 R14: 000000c0005fd1e0 R15: 000000c0000ae900 CPU: 1 PID: 64 Comm: kworker/u4:4 Not tainted 6.4.0-rc4-syzkaller-00031-g8b817fded42d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:236 Code: 01 00 00 49 89 f8 65 48 8b 14 25 00 bc 03 00 a9 00 01 ff 00 74 0e 85 f6 74 59 8b 82 0c 16 00 00 85 c0 74 4f 8b 82 e8 15 00 00 <83> f8 03 75 44 48 8b 82 f0 15 00 00 8b 92 ec 15 00 00 48 8b 38 48 RSP: 0018:ffffc9000206f940 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffe8ffffc02420 RCX: ffffffff817824d3 RDX: ffff888018ec8040 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: fffff91ffff80485 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd8701ad988 CR3: 000000000c571000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:285 [inline] smp_call_function_many_cond+0x6a3/0x15a0 kernel/smp.c:828 on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:996 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1770 [inline] text_poke_bp_batch+0x237/0x770 arch/x86/kernel/alternative.c:1970 text_poke_flush arch/x86/kernel/alternative.c:2161 [inline] text_poke_flush arch/x86/kernel/alternative.c:2158 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2168 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:831 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:823 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308