rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2647 jiffies s: 25977 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: 11638 Comm: syz.2.2498 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x60 kernel/kcov.c:216 Code: 48 8b 04 24 65 48 8b 0d 14 41 80 7e 65 8b 15 15 41 80 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 <74> 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b RSP: 0018:ffffc900001dfcd0 EFLAGS: 00000046 RAX: ffffffff8101179f RBX: ffff8880b8f35558 RCX: ffff88802ce18000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffc900001dfe77 R09: ffffc900001dfe40 R10: dffffc0000000000 R11: fffff5200003bfcf R12: dffffc0000000000 R13: ffff888056424e00 R14: 1ffff9200003bfd4 R15: dffffc0000000000 FS: 00007fb2387596c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb238717d58 CR3: 00000000432c8000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: user_mode arch/x86/include/asm/ptrace.h:136 [inline] perf_misc_flags+0x4f/0xc0 arch/x86/events/core.c:3050 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+0x457/0x630 kernel/events/core.c:9496 perf_swevent_overflow+0x19b/0x230 kernel/events/core.c:9579 perf_swevent_event+0x458/0x570 kernel/events/core.c:-1 perf_tp_event+0x36b/0xc10 kernel/events/core.c:10064 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032 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 a2 7c 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:ffffc900001e0580 EFLAGS: 00000206 RAX: 8b3d95da0cde8a00 RBX: 1ffff9200003c0b8 RCX: 8b3d95da0cde8a00 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0 RBP: ffffc900001e0670 R08: ffffffff90b1033f R09: 1ffffffff2162067 R10: dffffc0000000000 R11: fffffbfff2162068 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002 __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:737 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 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x2a0 mm/slub.c:3709 put_pid kernel/pid.c:114 [inline] delayed_put_pid+0xba/0x130 kernel/pid.c:123 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:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x36/0xa0 kernel/rcu/tree.c:721 Code: e8 6f 04 c4 08 89 c3 83 f8 08 73 60 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 80 f9 65 8c 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 40 32 67 00 48 c7 c3 08 58 03 00 49 03 1e 48 89 RSP: 0018:ffffc90005e8fc20 EFLAGS: 00000246 RAX: 1ffffffff18cbf31 RBX: 0000000000000001 RCX: 8b3d95da0cde8a00 RDX: 0000000000000000 RSI: ffffffff8adf5dc0 RDI: ffffffff8adf5d80 RBP: ffffc90005e8fd50 R08: ffffffff8e210aef R09: 1ffffffff1c4215d R10: dffffc0000000000 R11: fffffbfff1c4215e R12: dffffc0000000001 R13: dffffc0000000000 R14: ffffffff8c65f988 R15: dffffc0000000000 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xcf/0x920 kernel/locking/lockdep.c:5687 filename_create+0x2a9/0x450 fs/namei.c:3910 do_mkdirat+0xa5/0x440 fs/namei.c:4129 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152 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: 0033:0x7fb23779e0d9 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:00007fb238759028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fb237a25fa0 RCX: 00007fb23779e0d9 RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007fb237835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb237a26038 R14: 00007fb237a25fa0 R15: 00007ffe30cf6868