syzbot

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:
 <TASK>
 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
 </TASK>
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:
 <IRQ>
 </IRQ>
 <TASK>
 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
 </TASK>
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:
 <NMI>
 </NMI>
 <IRQ>
 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 <f3> 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
 </IRQ>
 <TASK>
 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
 </TASK>
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:
 <IRQ>
 </IRQ>
 <TASK>
 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
 </TASK>