rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2641 jiffies s: 3609 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:asm_sysvec_irq_work+0x0/0x20 arch/x86/include/asm/idtentry.h:722 Code: e9 b5 03 00 00 90 90 90 90 90 0f 01 ca fc 6a ff e8 b5 02 00 00 48 89 c4 48 89 e7 e8 9a a4 f3 ff e9 95 03 00 00 90 90 90 90 90 <0f> 01 ca fc 6a ff e8 95 02 00 00 48 89 c4 48 89 e7 e8 6a a9 f3 ff RSP: 0018:ffffc90000007718 EFLAGS: 00000006 RAX: 88a86dc642349500 RBX: 1ffff92000000ef0 RCX: 88a86dc642349500 RDX: dffffc0000000000 RSI: ffffffff8a8c19a0 RDI: ffffffff8adf71a0 RBP: ffffc90000007830 R08: ffff8880b8c357cb R09: 1ffff11017186af9 R10: dffffc0000000000 R11: ffffed1017186afa R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8c3bb00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000014c CR3: 000000007b52f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 68 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007740 EFLAGS: 00000206 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] is_bpf_text_address+0x27a/0x2a0 kernel/bpf/core.c:738 kernel_text_address+0x9c/0xd0 kernel/extable.c:125 __kernel_text_address+0x9/0x30 kernel/extable.c:79 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 ref_tracker_free+0x11b/0x830 lib/ref_tracker.c:121 netns_tracker_free include/net/net_namespace.h:336 [inline] put_net_track include/net/net_namespace.h:350 [inline] __sk_destruct+0x398/0x650 net/core/sock.c:2180 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x9a3/0x1740 kernel/rcu/tree.c:2557 handle_softirqs+0x291/0x910 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 b7 cb 95 f7 e9 44 ff ff ff e8 1d 02 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d e7 d1 48 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8d607da8 EFLAGS: 000002c2 RAX: 88a86dc642349500 RBX: ffffffff8a3ddba7 RCX: 88a86dc642349500 RDX: 0000000000000001 RSI: ffffffff8a8c19a0 RDI: ffffffff8adf71a0 RBP: ffffffff8d607ec8 R08: ffff8880b8c357cb R09: 1ffff11017186af9 R10: dffffc0000000000 R11: ffffed1017186afa R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8d6bc740 R15: 1ffffffff1ac0fc0 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a2/0x680 kernel/sched/idle.c:323 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422 rest_init+0x2dc/0x300 init/main.c:706 arch_call_rest_init+0xa/0xa init/main.c:865 start_kernel+0x480/0x50d init/main.c:1113 secondary_startup_64_no_verify+0xcf/0xdb INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.483 msecs