rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10501 ticks this GP) idle=92f/1/0x4000000000000000 softirq=22363/22363 fqs=0 (t=10502 jiffies g=21589 q=152) rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g21589 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=6866 rcu: rcu_preempt kthread starved for 10505 jiffies! g21589 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:27520 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 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/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145 kthread+0x42e/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: NMI backtrace for cpu 1 CPU: 1 PID: 12157 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_cpu_stall+0x31a/0x5f0 kernel/rcu/tree_stall.h:631 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ec/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+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 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:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90004a6e440 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0aa9822a4c0e6e00 RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a79c980 RBP: ffffc90004a6e560 R08: dffffc0000000000 R09: 1ffffffff2039618 R10: dffffc0000000000 R11: fffffbfff2039619 R12: ffffffff8c31ef20 R13: 1ffff9200094dc94 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] tipc_sk_lookup+0xbc/0x8d0 net/tipc/socket.c:3000 tipc_sk_rcv+0x38e/0x2a10 net/tipc/socket.c:2494 tipc_node_xmit+0x203/0xf70 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x2c7/0x3f0 net/tipc/node.c:1783 tipc_sk_rcv+0x24ac/0x2a10 net/tipc/socket.c:2503 tipc_node_xmit+0x203/0xf70 net/tipc/node.c:1703 tipc_sk_push_backlog net/tipc/socket.c:1316 [inline] tipc_sk_filter_connect net/tipc/socket.c:2257 [inline] tipc_sk_filter_rcv+0x1b1a/0x30b0 net/tipc/socket.c:2366 tipc_sk_enqueue net/tipc/socket.c:2447 [inline] tipc_sk_rcv+0x846/0x2a10 net/tipc/socket.c:2499 tipc_node_xmit+0x203/0xf70 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x2c7/0x3f0 net/tipc/node.c:1783 tipc_sk_backlog_rcv+0x1aa/0x260 net/tipc/socket.c:2414 sk_backlog_rcv include/net/sock.h:1080 [inline] __release_sock+0x1e6/0x460 net/core/sock.c:2731 release_sock+0x5b/0x1b0 net/core/sock.c:3274 sock_setsockopt+0x1ba3/0x2480 net/core/sock.c:1379 __sys_setsockopt+0x2f6/0x3d0 net/socket.c:2209 __do_sys_setsockopt net/socket.c:2224 [inline] __se_sys_setsockopt net/socket.c:2221 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2221 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: 0033:0x7fa691c79279 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa6910090b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fa691db6f80 RCX: 00007fa691c79279 RDX: 0000000000000021 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 00007fa691cda49c R08: 0000000000000004 R09: 0000000000000000 R10: 0000000020000040 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fa691db6f80 R15: 00007fffccdc2348 NMI backtrace for cpu 1 CPU: 1 PID: 12157 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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+0x22d/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31f/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+0x6ec/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+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 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:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90004a6e440 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0aa9822a4c0e6e00 RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a79c980 RBP: ffffc90004a6e560 R08: dffffc0000000000 R09: 1ffffffff2039618 R10: dffffc0000000000 R11: fffffbfff2039619 R12: ffffffff8c31ef20 R13: 1ffff9200094dc94 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] tipc_sk_lookup+0xbc/0x8d0 net/tipc/socket.c:3000 tipc_sk_rcv+0x38e/0x2a10 net/tipc/socket.c:2494 tipc_node_xmit+0x203/0xf70 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x2c7/0x3f0 net/tipc/node.c:1783 tipc_sk_rcv+0x24ac/0x2a10 net/tipc/socket.c:2503 tipc_node_xmit+0x203/0xf70 net/tipc/node.c:1703 tipc_sk_push_backlog net/tipc/socket.c:1316 [inline] tipc_sk_filter_connect net/tipc/socket.c:2257 [inline] tipc_sk_filter_rcv+0x1b1a/0x30b0 net/tipc/socket.c:2366 tipc_sk_enqueue net/tipc/socket.c:2447 [inline] tipc_sk_rcv+0x846/0x2a10 net/tipc/socket.c:2499 tipc_node_xmit+0x203/0xf70 net/tipc/node.c:1703 tipc_node_xmit_skb net/tipc/node.c:1768 [inline] tipc_node_distr_xmit+0x2c7/0x3f0 net/tipc/node.c:1783 tipc_sk_backlog_rcv+0x1aa/0x260 net/tipc/socket.c:2414 sk_backlog_rcv include/net/sock.h:1080 [inline] __release_sock+0x1e6/0x460 net/core/sock.c:2731 release_sock+0x5b/0x1b0 net/core/sock.c:3274 sock_setsockopt+0x1ba3/0x2480 net/core/sock.c:1379 __sys_setsockopt+0x2f6/0x3d0 net/socket.c:2209 __do_sys_setsockopt net/socket.c:2224 [inline] __se_sys_setsockopt net/socket.c:2221 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2221 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: 0033:0x7fa691c79279 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa6910090b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fa691db6f80 RCX: 00007fa691c79279 RDX: 0000000000000021 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 00007fa691cda49c R08: 0000000000000004 R09: 0000000000000000 R10: 0000000020000040 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fa691db6f80 R15: 00007fffccdc2348