rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=673/1/0x4000000000000000 softirq=24987/24993 fqs=36 (t=10500 jiffies g=28309 q=1662) rcu: rcu_preempt kthread timer wakeup didn't happen for 10418 jiffies! g28309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=7391 rcu: rcu_preempt kthread starved for 10419 jiffies! g28309 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:28016 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 16221 Comm: syz.3.3515 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x527/0x9c0 kernel/locking/qspinlock.c:508 Code: 00 41 c6 45 00 00 48 8b 44 24 10 42 0f b6 04 38 84 c0 0f 85 1c 01 00 00 48 8b 44 24 08 c6 00 01 41 bd 00 80 ff ff eb 07 f3 90 <41> ff c5 74 47 43 0f b6 04 3e 84 c0 75 2b 80 3b 00 75 eb 48 89 df RSP: 0018:ffffc9000327fa80 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff88807da05b88 RCX: 76a0cb68b4970900 RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0 RBP: ffffc9000327fb78 R08: ffffffff901d8207 R09: 1ffffffff203b040 R10: dffffc0000000000 R11: fffffbfff203b041 R12: 1ffff11017220001 R13: 00000000ffffb2c0 R14: 1ffff1100fb40b71 R15: dffffc0000000000 FS: 00005555892a3500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558fbf7a48 CR3: 0000000058a9d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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+0x265/0x2f0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:369 [inline] lock_sock_nested+0x68/0x100 net/core/sock.c:3262 lock_sock include/net/sock.h:1744 [inline] tipc_release+0xa2/0x1ff0 net/tipc/socket.c:639 __sock_release net/socket.c:651 [inline] sock_close+0xd5/0x240 net/socket.c:1345 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4b59f6d479 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd27fef538 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f4b5a19dba0 RCX: 00007f4b59f6d479 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f4b5a19dba0 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f4b5a19dac0 R11: 0000000000000246 R12: 000000000002e960 R13: 00007ffd27fef660 R14: 000000000002e658 R15: 00007f4b5a19c080 NMI backtrace for cpu 0 CPU: 0 PID: 16222 Comm: syz.3.3515 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 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+0x6ea/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 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:1685 [inline] __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 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_is_a_nulls include/linux/rhashtable.h:110 [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+0x35f/0x8d0 net/tipc/socket.c:3001 Code: ff 0f 84 2b 01 00 00 e8 df d6 0f f8 eb 05 e8 d8 d6 0f f8 49 83 e6 fe 31 ff 4c 89 f6 e8 aa da 0f f8 4d 85 f6 4c 0f 44 74 24 48 <4c> 89 f6 48 83 e6 01 31 ff e8 93 da 0f f8 4c 89 f0 48 83 e0 01 0f RSP: 0018:ffffc9000325e3c0 EFLAGS: 00000282 RAX: ffffffff89697226 RBX: ffff88805bd404c8 RCX: ffff88802b3c8000 RDX: 0000000000000000 RSI: ffff88807da060b0 RDI: 0000000000000000 RBP: ffffc9000325e4d0 R08: dffffc0000000000 R09: 1ffffffff203b018 R10: dffffc0000000000 R11: fffffbfff203b019 R12: ffff88805bd40000 R13: dffffc0000000000 R14: ffff88807da060b0 R15: 0000000000000001 tipc_sk_rcv+0x38e/0x29f0 net/tipc/socket.c:2494 tipc_node_xmit+0x1eb/0xf20 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x2d2/0x3f0 net/tipc/node.c:1783 tipc_sk_rcv+0x2492/0x29f0 net/tipc/socket.c:2503 tipc_node_xmit+0x1eb/0xf20 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+0x8bb/0x1730 net/tipc/socket.c:2158 tipc_sk_filter_rcv+0x2f42/0x3170 net/tipc/socket.c:2354 tipc_sk_enqueue net/tipc/socket.c:2447 [inline] tipc_sk_rcv+0x847/0x29f0 net/tipc/socket.c:2499 tipc_node_xmit+0x1eb/0xf20 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x2d2/0x3f0 net/tipc/node.c:1783 tipc_sk_backlog_rcv+0x1b8/0x270 net/tipc/socket.c:2414 sk_backlog_rcv include/net/sock.h:1080 [inline] __release_sock+0x1e1/0x450 net/core/sock.c:2731 release_sock+0x5b/0x1b0 net/core/sock.c:3274 sock_setsockopt+0x1928/0x24c0 net/core/sock.c:1379 __sys_setsockopt+0x2f6/0x3d0 net/socket.c:2208 __do_sys_setsockopt net/socket.c:2223 [inline] __se_sys_setsockopt net/socket.c:2220 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2220 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: 0033:0x7f4b59f6d479 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4b591d4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f4b5a19bfa0 RCX: 00007f4b59f6d479 RDX: 0000000000000021 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 00007f4b59ffe1bc R08: 0000000000000004 R09: 0000000000000000 R10: 0000400000000540 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4b5a19bfa0 R15: 00007ffd27fef3d8