rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (0 ticks this GP) idle=477/1/0x4000000000000002 softirq=9271/9271 fqs=5250 (detected by 1, t=10502 jiffies, g=9401, q=171) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4201 Comm: syz-executor223 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:172 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x60 kernel/kcov.c:206 Code: 48 8b 04 24 65 48 8b 0d 04 73 89 7e 65 8b 15 05 73 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 <74> 2c 8b 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b RSP: 0018:ffffc90000006e10 EFLAGS: 00000046 RAX: ffffffff81978799 RBX: 0000000000000000 RCX: ffff88807e7cbb80 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffc90000006fd7 R09: ffffc90000006fa0 R10: dffffc0000000000 R11: fffff52000000dfb R12: ffff8880784260da R13: ffffc900000071c0 R14: ffff888078425f80 R15: ffffc90000007006 FS: 0000555580492480(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555580492328 CR3: 000000007d2ff000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __perf_event_header__init_id+0x389/0x4f0 kernel/events/core.c:7115 perf_prepare_sample+0x158/0x1cb0 kernel/events/core.c:7624 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x35f/0x550 kernel/events/core.c:9515 perf_swevent_overflow kernel/events/core.c:9591 [inline] perf_swevent_event+0x4b8/0x540 kernel/events/core.c:9629 perf_tp_event+0x324/0xbe0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 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 02 20 9d 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900000075e0 EFLAGS: 00000206 RAX: 27919e01379f2e00 RBX: 1ffff92000000ec0 RCX: 27919e01379f2e00 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4200 RBP: ffffc900000076c0 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffffff8c323400 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] is_bpf_text_address+0x24f/0x270 kernel/bpf/core.c:727 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 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:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 rcu_do_batch kernel/rcu/tree.c:2523 [inline] rcu_core+0x96e/0x1650 kernel/rcu/tree.c:2763 handle_softirqs+0x336/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:do_user_addr_fault+0x204/0xc90 arch/x86/include/asm/irqflags.h:-1 Code: 02 00 00 31 ff e8 fc 8a 43 00 48 81 e3 00 02 00 00 75 07 e8 0e 87 43 00 eb 0b e8 07 87 43 00 e8 32 ad 49 00 fb bb 14 02 00 00 <4c> 89 7c 24 20 0f 1f 44 00 00 e8 ed 86 43 00 45 89 f7 41 83 e7 02 RSP: 0018:ffffc90002d0fc10 EFLAGS: 00000282 RAX: 27919e01379f2e00 RBX: 0000000000000214 RCX: 27919e01379f2e00 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4200 RBP: dffffc0000000000 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000555580492328 R13: ffffc90002d0fce8 R14: 0000000000000003 R15: ffff88801be3b800 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0010:__put_user_nocheck_8+0x3/0x21 Code: 00 00 48 39 d9 73 34 0f 01 cb 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 48 bb f9 ef ff ff ff 7f 00 00 48 39 d9 73 14 0f 01 cb <48> 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 0f 01 ca b9 f2 ff ff ff RSP: 0018:ffffc90002d0fd98 EFLAGS: 00050293 RAX: 0000000000000000 RBX: 00007fffffffeff9 RCX: 0000555580492328 RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4200 RBP: ffffc90002d0fec0 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd R10: dffffc0000000000 R11: fffffbfff1b161be R12: ffffc90002d0ffd8 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920005a1fc0 clear_rseq_cs kernel/rseq.c:242 [inline] rseq_ip_fixup kernel/rseq.c:276 [inline] __rseq_handle_notify_resume+0x554/0xf40 kernel/rseq.c:314 rseq_handle_notify_resume include/linux/sched.h:2210 [inline] tracehook_notify_resume include/linux/tracehook.h:201 [inline] exit_to_user_mode_loop+0xe5/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd22a764cd7 Code: 48 89 fa 4c 89 df e8 b8 13 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc1aa0b780 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 0000555580492480 RCX: 00007fd22a764cd7 RDX: 00007ffc1aa0b7c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc1aa0b804 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000016e R13: 431bde82d7b634db R14: 000000000001b74b R15: 00007ffc1aa0b860 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.996 msecs