rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=359/1/0x4000000000000000 softirq=168339/168340 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10913/1:b..l (detected by 0, t=10502 jiffies, g=326957, q=70) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 30933 Comm: syz-executor.5 Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:344 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:895 [inline] RIP: 0010:trace_hrtimer_expire_exit include/trace/events/timer.h:279 [inline] RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1688 [inline] RIP: 0010:__hrtimer_run_queues+0x20a/0xe50 kernel/time/hrtimer.c:1749 Code: 07 00 00 00 44 89 e6 e8 24 61 10 00 41 83 fc 07 0f 87 c8 0a 00 00 e8 65 58 10 00 45 89 e4 be 08 00 00 00 4c 89 e0 48 c1 f8 06 <48> 8d 3c c5 50 26 6e 8d e8 e9 2a 57 00 4c 0f a3 25 91 49 09 0c 41 RSP: 0018:ffffc90000fd8698 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88807d9c2340 RCX: 0000000000000100 RDX: ffff8880841401c0 RSI: 0000000000000008 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000007 R09: 0000000000000000 R10: ffffffff8164dc8c R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880b9d225c0 R14: ffff8880b9d223c0 R15: 0000000000000001 FS: 00007fe937c02700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff2224f9718 CR3: 000000007a1cb000 CR4: 00000000003506e0 Call Trace: hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:write_comp_data kernel/kcov.c:218 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0x4f/0xf0 kernel/kcov.c:320 Code: 84 aa 00 00 00 48 83 f8 10 0f 85 83 00 00 00 bb 03 00 00 00 4d 8b 10 31 c9 65 4c 8b 24 25 40 f0 01 00 4d 85 d2 74 6b 4c 89 e6 03 00 00 00 4c 8b 4c 24 20 49 8b 6c c8 10 e8 2d ff ff ff 84 c0 RSP: 0018:ffffc90000fd8918 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000003 RDX: 0000000000000000 RSI: ffff8880841401c0 RDI: 0000000000000003 RBP: 0000000000000007 R08: ffffffff8a9ab920 R09: ffffffff87d61a17 R10: 0000000000000004 R11: 000000000000000a R12: ffff8880841401c0 R13: ffff8880878ae140 R14: 0000000000000001 R15: ffff888014f80000 nf_hook+0xf7/0x680 include/linux/netfilter.h:227 NF_HOOK_COND include/linux/netfilter.h:295 [inline] ip6_output+0x327/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x3f2/0x820 net/ipv6/addrconf.c:3893 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 do_softirq.part.0+0xde/0x130 kernel/softirq.c:459 do_softirq kernel/softirq.c:451 [inline] __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:383 spin_unlock_bh include/linux/spinlock.h:408 [inline] __fib6_clean_all+0x10f/0x2a0 net/ipv6/ip6_fib.c:2257 rt6_sync_up+0xce/0x170 net/ipv6/route.c:4774 addrconf_notify+0x145f/0x1bb0 net/ipv6/addrconf.c:3579 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1996 netdev_state_change net/core/dev.c:1387 [inline] netdev_state_change+0x100/0x130 net/core/dev.c:1380 do_setlink+0x2e24/0x3970 net/core/rtnetlink.c:2944 rtnl_group_changelink net/core/rtnetlink.c:3242 [inline] __rtnl_newlink+0xc06/0x1750 net/core/rtnetlink.c:3396 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3506 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5572 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2510 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1935 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe93a68b8d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe937c02188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe93a78ff60 RCX: 00007fe93a68b8d9 RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000004 RBP: 00007fe93a6e5cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc6f601c1f R14: 00007fe937c02300 R15: 0000000000022000 task:kworker/0:4 state:R running task stack:23712 pid:10913 ppid: 2 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6687 irqentry_exit+0x31/0x80 kernel/entry/common.c:425 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:197 Code: 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 3c 15 00 00 85 c0 74 2b 8b 82 18 15 00 00 <83> f8 02 75 20 48 8b 8a 20 15 00 00 8b 92 1c 15 00 00 48 8b 01 48 RSP: 0018:ffffc90004c7fca0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888090b08040 RSI: ffffffff876258af RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8fd029af R10: ffffffff876258a6 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000040000 R15: 00000000fffff916 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:326 [inline] gc_worker+0x21f/0x1030 net/netfilter/nf_conntrack_core.c:1441 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10498 jiffies! g326957 f0x0 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:28832 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 6181 Comm: kworker/u4:0 Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode+0x2e/0x40 kernel/kcov.c:174 Code: c3 8c 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 3c 15 00 00 85 d2 74 0b 8b 86 18 15 00 00 39 f8 <0f> 94 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 65 8b RSP: 0018:ffffc900060079e8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d37180 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff888085b74080 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff8169e956 R11: 0000000000000000 R12: ffffed10173a6e31 R13: 0000000000000001 R14: ffff8880b9d37188 R15: 0000000000000001 write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp4+0x1c/0x70 kernel/kcov.c:284 csd_lock_wait kernel/smp.c:440 [inline] smp_call_function_many_cond+0x476/0xc20 kernel/smp.c:969 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:929 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1114 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:626 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:618 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: 00 44 89 e6 add %al,-0x1a(%rcx,%rcx,4) 6: e8 24 61 10 00 callq 0x10612f b: 41 83 fc 07 cmp $0x7,%r12d f: 0f 87 c8 0a 00 00 ja 0xadd 15: e8 65 58 10 00 callq 0x10587f 1a: 45 89 e4 mov %r12d,%r12d 1d: be 08 00 00 00 mov $0x8,%esi 22: 4c 89 e0 mov %r12,%rax 25: 48 c1 f8 06 sar $0x6,%rax * 29: 48 8d 3c c5 50 26 6e lea -0x7291d9b0(,%rax,8),%rdi <-- trapping instruction 30: 8d 31: e8 e9 2a 57 00 callq 0x572b1f 36: 4c 0f a3 25 91 49 09 bt %r12,0xc094991(%rip) # 0xc0949cf 3d: 0c 3e: 41 rex.B