rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10139 ticks this GP) idle=c83c/1/0x4000000000000000 softirq=38827/38994 fqs=5236 rcu: hardirqs softirqs csw/system rcu: number: 1287193 0 0 rcu: cputime: 18581 33907 69 ==> 52500(ms) rcu: (t=10502 jiffies g=50385 q=1854 ncpus=2) CPU: 0 PID: 11859 Comm: syz.2.1595 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:__sanitizer_cov_trace_pc+0x17/0x60 kernel/kcov.c:216 Code: 48 8b 3d cc cb 03 0d 48 89 de 5b e9 d3 5f 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d a0 a0 7c 7e 65 8b 15 a1 a0 7c 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 RSP: 0018:ffffc90000007298 EFLAGS: 00000246 RAX: ffffffff813b6c79 RBX: ffffc900000073e0 RCX: ffff88804ee71e00 RDX: 0000000000000102 RSI: 0000000000000002 RDI: ffffc900000073e0 RBP: ffffc90000007438 R08: ffff88804ee71e00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900000073e8 R13: dffffc0000000000 R14: ffffc900000073e0 R15: ffffffff8f0d5dc4 FS: 00007f4d6e9706c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32323ffc CR3: 00000000482ed000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __read_once_word_nocheck+0x9/0x10 include/asm-generic/rwonce.h:66 deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline] unwind_next_frame+0x15f9/0x2970 arch/x86/kernel/unwind_orc.c:585 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 __kfence_alloc+0x2d7/0x3d0 mm/kfence/core.c:1116 kfence_alloc include/linux/kfence.h:129 [inline] slab_alloc_node mm/slub.c:3481 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x27d/0x2d0 mm/slub.c:3519 dst_alloc+0x105/0x170 net/core/dst.c:89 ip6_dst_alloc net/ipv6/route.c:344 [inline] icmp6_dst_alloc+0x7b/0x400 net/ipv6/route.c:3316 ndisc_send_skb+0x44e/0x14f0 net/ipv6/ndisc.c:493 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:generic_exec_single+0x481/0x4f0 kernel/smp.c:418 Code: 75 11 e8 72 03 0b 00 48 85 db 75 16 e8 68 03 0b 00 eb 15 e8 61 03 0b 00 e8 cc 5a 08 09 48 85 db 74 ea e8 52 03 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 43 c7 44 2c 08 RSP: 0018:ffffc90004b2fa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc90014a80000 RSI: 000000000000663b RDI: 000000000000663c RBP: ffffc90004b2fad0 R08: ffffffff911bf5ff R09: 1ffffffff2237ebf R10: dffffc0000000000 R11: fffffbfff2237ec0 R12: 1ffff92000965f44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000965f65 smp_call_function_single+0x36d/0x5a0 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5be/0x920 kernel/events/core.c:2948 __do_sys_perf_event_open kernel/events/core.c:12915 [inline] __se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4d6db9c799 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:00007f4d6e970028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f4d6de15fa0 RCX: 00007f4d6db9c799 RDX: feffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007f4d6dc32bd9 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4d6de16038 R14: 00007f4d6de15fa0 R15: 00007ffc1c19fa38