rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=5df/1/0x4000000000000000 softirq=154672/154672 fqs=0 (t=10500 jiffies g=297429 q=61) rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g297429 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=112719 rcu: rcu_preempt kthread starved for 10500 jiffies! g297429 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28688 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13428 Comm: kworker/u4:4 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__radix_tree_lookup+0x53/0x2a0 lib/radix-tree.c:756 Code: 4c 24 08 e8 8f 7b 78 fd 48 8d 43 48 48 89 44 24 20 48 c1 e8 03 48 01 e8 48 89 44 24 18 e8 75 7b 78 fd 48 8b 44 24 18 80 38 00 <0f> 85 06 02 00 00 48 8b 44 24 10 bf 02 00 00 00 4c 8b 60 48 4c 89 RSP: 0018:ffffc90006817b88 EFLAGS: 00000246 RAX: ffffed100ccaeb89 RBX: ffff888066575c00 RCX: 0000000000000000 RDX: ffff888078af3a00 RSI: ffffffff83ff1deb RDI: ffff888066575c00 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88ba7ee9 R11: 0000000000000000 R12: ffff888066575c58 R13: ffffed100ccaeb93 R14: 0000000074ec237d R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb822f30718 CR3: 000000004e82e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tipc_topsrv_stop net/tipc/topsrv.c:691 [inline] tipc_topsrv_exit_net+0x20a/0x5d0 net/tipc/topsrv.c:715 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13428 Comm: kworker/u4:4 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:200 Code: 46 00 5d be 03 00 00 00 e9 f6 14 63 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 99 d6 8a 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 70 02 00 a9 RSP: 0018:ffffc90006817be0 EFLAGS: 00000202 RAX: 0000000000000201 RBX: 0000000075148805 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff888078af3a00 RDI: 0000000000000003 RBP: ffff888066575c00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff88ba7ee9 R11: 0000000000000000 R12: ffff888066575c58 R13: ffffed100ccaeb93 R14: ffff888036a23c00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb822f30718 CR3: 000000004e82e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tipc_topsrv_stop net/tipc/topsrv.c:691 [inline] tipc_topsrv_exit_net+0x1ff/0x5d0 net/tipc/topsrv.c:715 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:168 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:593 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 1 CPU: 1 PID: 1351 Comm: kworker/u4:5 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tipc_rcv tipc_conn_recv_work 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:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 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:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1001 Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 73 56 4a 00 eb 07 0f 00 2d ea 8f 75 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 36 51 4a 00 8b 74 24 0c RSP: 0018:ffffc90005d2fb08 EFLAGS: 00000202 RAX: 0000000002a84434 RBX: 0000000000000000 RCX: 1ffffffff1ffaca6 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: ffff888066575c58 R08: 0000000000000001 R09: ffffffff8ff72b0f R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: ffffed100ccaeb8b R14: 0000000000000001 R15: ffff8880b9d3a880 pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:354 [inline] tipc_conn_kref_release+0x47/0x380 net/tipc/topsrv.c:129 kref_put include/linux/kref.h:65 [inline] conn_put net/tipc/topsrv.c:147 [inline] tipc_conn_recv_work+0x14a/0x190 net/tipc/topsrv.c:430 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 4c 24 08 rex.WR and $0x8,%al 3: e8 8f 7b 78 fd callq 0xfd787b97 8: 48 8d 43 48 lea 0x48(%rbx),%rax c: 48 89 44 24 20 mov %rax,0x20(%rsp) 11: 48 c1 e8 03 shr $0x3,%rax 15: 48 01 e8 add %rbp,%rax 18: 48 89 44 24 18 mov %rax,0x18(%rsp) 1d: e8 75 7b 78 fd callq 0xfd787b97 22: 48 8b 44 24 18 mov 0x18(%rsp),%rax 27: 80 38 00 cmpb $0x0,(%rax) * 2a: 0f 85 06 02 00 00 jne 0x236 <-- trapping instruction 30: 48 8b 44 24 10 mov 0x10(%rsp),%rax 35: bf 02 00 00 00 mov $0x2,%edi 3a: 4c 8b 60 48 mov 0x48(%rax),%r12 3e: 4c rex.WR 3f: 89 .byte 0x89