syzbot

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2641 jiffies s: 20361 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10449 Comm: syz.1.2251 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x23/0x80 kernel/kcov.c:313
Code: 48 89 44 11 20 c3 90 48 8b 04 24 65 48 8b 15 24 f9 7f 7e 65 8b 0d 25 f9 7f 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b <83> ba 1c 16 00 00 00 74 52 8b 8a f8 15 00 00 83 f9 03 75 47 48 8b
RSP: 0018:ffffc900001e0268 EFLAGS: 00000046
RAX: ffffffff810a3f36 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff88807d8a8000 RSI: 0000000000000101 RDI: 0000000000000000
RBP: 0000000000000101 R08: ffffc900001e0437 R09: ffffc900001e0400
R10: dffffc0000000000 R11: fffff5200003c087 R12: dffffc0000000000
R13: ffff88804c651800 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f438c9756c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fb1bff8 CR3: 000000007acfe000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 should_resched arch/x86/include/asm/preempt.h:103 [inline]
 kvm_get_running_vcpu virt/kvm/kvm_main.c:5841 [inline]
 kvm_guest_state+0x46/0xf0 virt/kvm/kvm_main.c:5858
 perf_guest_state include/linux/perf_event.h:1332 [inline]
 perf_misc_flags+0x1d/0xc0 arch/x86/events/core.c:3041
 perf_prepare_sample+0x12f/0x2020 kernel/events/core.c:7529
 __perf_event_output kernel/events/core.c:7730 [inline]
 perf_event_output_forward+0x197/0x2f0 kernel/events/core.c:7750
 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
 perf_tp_event+0x38c/0xc00 kernel/events/core.c:10029
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10002
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
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 e2 33 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:ffffc900001e0a00 EFLAGS: 00000206
RAX: 21d1870fb98ca200 RBX: 1ffff9200003c148 RCX: 21d1870fb98ca200
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0f60
RBP: ffffc900001e0af8 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 fib6_nh_release+0x22a/0x2b0 net/ipv6/route.c:3696
 fib6_info_destroy_rcu+0xba/0x1b0 net/ipv6/ip6_fib.c:176
 rcu_do_batch kernel/rcu/tree.c:2297 [inline]
 rcu_core+0xa99/0x1740 kernel/rcu/tree.c:2557
 handle_softirqs+0x2a1/0x930 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:debug_check_no_locks_freed+0x6/0x3e0 kernel/locking/lockdep.c:6453
Code: d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b e9 4f ff ff ff e8 7c 1d c8 08 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 00 00 48 89 74 24
RSP: 0018:ffffc90003417d20 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888077361dc0 RCX: ffffffff81638449
RDX: ffffffff9704bdc0 RSI: 0000000000000090 RDI: ffff888077361dc0
RBP: ffffc90003417d28 R08: ffff888077361e0b R09: 1ffff1100ee6c3c1
R10: dffffc0000000000 R11: ffffed100ee6c3c2 R12: ffff888077361e68
R13: ffff888076d70000 R14: ffffffff9704bdc0 R15: ffffffff8b977a40
 debug_mutex_init+0x18/0x70 kernel/locking/mutex-debug.c:87
 unix_create1+0x25b/0x710 net/unix/af_unix.c:971
 unix_create+0x143/0x1f0 net/unix/af_unix.c:1017
 __sock_create+0x4a2/0x940 net/socket.c:1549
 sock_create net/socket.c:1605 [inline]
 __sys_socketpair+0x1bd/0x540 net/socket.c:1732
 __do_sys_socketpair net/socket.c:1785 [inline]
 __se_sys_socketpair net/socket.c:1782 [inline]
 __x64_sys_socketpair+0x97/0xb0 net/socket.c:1782
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f438bb9c799
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:00007f438c975028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f438be15fa0 RCX: 00007f438bb9c799
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 00007f438bc32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f438be16038 R14: 00007f438be15fa0 R15: 00007ffc2c2c4af8
 </TASK>