rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=f87/1/0x4000000000000000 softirq=11516/11524 fqs=0 (t=10502 jiffies g=14629 q=42) rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g14629 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=8149 rcu: rcu_preempt kthread starved for 10505 jiffies! g14629 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:27848 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 6222 Comm: syz.0.398 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:kvm_wait+0x141/0x190 arch/x86/kernel/kvm.c:918 Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 47 0f b6 1f e8 0f e1 49 00 44 38 e3 75 10 66 90 0f 00 2d e1 63 d4 08 fb f4 33 ff ff ff fb e9 2d ff ff ff e8 df e5 74 08 89 f9 80 e1 07 38 RSP: 0018:ffffc9000bdaf780 EFLAGS: 00000246 RAX: 94cea197e59d8800 RBX: 0000000000000003 RCX: 94cea197e59d8800 RDX: dffffc0000000000 RSI: ffffffff8a0b1620 RDI: ffffffff8a59a240 RBP: ffffc9000bdaf830 R08: dffffc0000000000 R09: fffffbfff1ff7640 R10: fffffbfff1ff7640 R11: 1ffffffff1ff763f R12: 0000000000000003 R13: ffff8880b903b114 R14: dffffc0000000000 R15: 1ffff920017b5ef0 FS: 00007f2429a276c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000400000000000 CR3: 0000000059fbc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:597 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x60f/0x9c0 kernel/locking/qspinlock.c:508 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:368 [inline] lock_sock_nested+0x68/0x100 net/core/sock.c:3254 lock_sock include/net/sock.h:1694 [inline] tipc_sendstream+0x43/0x70 net/tipc/socket.c:1549 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg+0x190/0x250 net/socket.c:2526 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f242a7b6169 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2429a27038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f242a9cefa0 RCX: 00007f242a7b6169 RDX: 0000000000000000 RSI: 00004000000002c0 RDI: 0000000000000004 RBP: 00007f242a8372a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f242a9cefa0 R15: 00007fff55ae8108 NMI backtrace for cpu 1 CPU: 1 PID: 6223 Comm: syz.0.398 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:rht_ptr_rcu include/linux/rhashtable.h:369 [inline] RIP: 0010:__rhashtable_lookup include/linux/rhashtable.h:599 [inline] RIP: 0010:rhashtable_lookup include/linux/rhashtable.h:638 [inline] RIP: 0010:tipc_sk_lookup+0x2fa/0x8d0 net/tipc/socket.c:2999 Code: 49 8d 9c c4 80 00 00 00 48 89 d8 48 83 c8 01 48 89 44 24 48 48 89 d8 48 c1 e8 03 48 89 44 24 78 48 89 5c 24 70 48 8b 44 24 78 <42> 80 3c 28 00 74 08 48 89 df e8 97 ca 65 f8 4c 8b 33 e8 3f 8d 52 RSP: 0018:ffffc9000bdbe380 EFLAGS: 00000a06 RAX: 1ffff1100f1d188e RBX: ffff888078e8c470 RCX: ffff88807f635940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000bdbe490 R08: dffffc0000000000 R09: fffffbfff1ff7619 R10: fffffbfff1ff7619 R11: 1ffffffff1ff7618 R12: ffff888078e8c000 R13: dffffc0000000000 R14: 000000000000007e R15: 0000000000000000 tipc_sk_rcv+0x3f6/0x2be0 net/tipc/socket.c:2492 tipc_node_xmit+0x1b9/0xe50 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x29a/0x3a0 net/tipc/node.c:1783 tipc_sk_rcv+0x2693/0x2be0 net/tipc/socket.c:2501 tipc_node_xmit+0x1b9/0xe50 net/tipc/node.c:1703 tipc_sk_push_backlog+0x4ef/0x8f0 net/tipc/socket.c:1316 tipc_sk_conn_proto_rcv net/tipc/socket.c:1370 [inline] tipc_sk_proto_rcv+0x8fc/0x16b0 net/tipc/socket.c:2158 tipc_sk_filter_rcv+0x2dd1/0x3000 net/tipc/socket.c:2352 tipc_sk_enqueue net/tipc/socket.c:2445 [inline] tipc_sk_rcv+0x8a2/0x2be0 net/tipc/socket.c:2497 tipc_node_xmit+0x1b9/0xe50 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x29a/0x3a0 net/tipc/node.c:1783 tipc_sk_backlog_rcv+0x19e/0x230 net/tipc/socket.c:2412 sk_backlog_rcv include/net/sock.h:1061 [inline] __release_sock+0x1b9/0x420 net/core/sock.c:2725 release_sock+0x5b/0x1b0 net/core/sock.c:3266 sock_setsockopt+0x1502/0x2270 net/core/sock.c:1379 __sys_setsockopt+0x2f6/0x3d0 net/socket.c:2199 __do_sys_setsockopt net/socket.c:2214 [inline] __se_sys_setsockopt net/socket.c:2211 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2211 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f242a7b6169 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2429a06038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f242a9cf080 RCX: 00007f242a7b6169 RDX: 0000000000000021 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 00007f242a8372a0 R08: 0000000000000004 R09: 0000000000000000 R10: 0000400000000540 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f242a9cf080 R15: 00007fff55ae8108