rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=47e4/1/0x4000000000000000 softirq=54382/54383 fqs=5248 rcu: hardirqs softirqs csw/system rcu: number: 14395751 0 0 rcu: cputime: 6023 46493 0 ==> 52500(ms) rcu: (detected by 1, t=10502 jiffies, g=53205, q=891 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22339 Comm: syz.2.7694 Not tainted 6.6.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212 Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 8c f1 c4 0c 48 89 de 5b e9 63 75 56 00 cc cc cc 0f 1e fa 48 8b 04 24 65 48 8b 0d 60 24 7e 7e 65 8b 15 61 24 7e RSP: 0018:ffffc90000007218 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000510 RCX: ffff888028c69e00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007310 R08: dffffc0000000000 R09: 1ffffffff21b46a4 R10: dffffc0000000000 R11: fffffbfff21b46a5 R12: ffffc90000007600 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000010 FS: 00007f18aaa406c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f263fff CR3: 000000003093d000 CR4: 00000000003506f0 Call Trace: perf_prepare_sample+0x511/0x1c40 kernel/events/core.c:7783 __perf_event_output kernel/events/core.c:7957 [inline] perf_event_output_forward+0x152/0x3a0 kernel/events/core.c:7978 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9703 perf_swevent_overflow kernel/events/core.c:9779 [inline] perf_swevent_event+0x2f5/0x5c0 kernel/events/core.c:-1 perf_tp_event+0x4f9/0x13a0 kernel/events/core.c:10329 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10253 perf_trace_preemptirq_template+0x281/0x340 include/trace/events/preemptirq.h:14 trace_irq_enable+0xbf/0xe0 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723 RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc90000007a00 EFLAGS: 00000206 RAX: 34e02ea4cc447100 RBX: 1ffff92000000f48 RCX: 34e02ea4cc447100 RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780 RBP: ffffc90000007b00 R08: ffffffff90da362f R09: 1ffffffff21b46c5 R10: dffffc0000000000 R11: fffffbfff21b46c6 R12: ffffffff8cd35400 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:818 [inline] process_backlog+0x403/0x6e0 net/core/dev.c:6039 __napi_poll+0xc0/0x460 net/core/dev.c:6600 napi_poll net/core/dev.c:6667 [inline] net_rx_action+0x5ea/0xbf0 net/core/dev.c:6803 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+0xc7/0x190 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+0x476/0x4f0 kernel/smp.c:418 Code: 75 11 e8 3d e6 0a 00 48 85 db 75 16 e8 33 e6 0a 00 eb 15 e8 2c e6 0a 00 e8 27 69 f2 08 48 85 db 74 ea e8 1d e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c RSP: 0018:ffffc9000d18fa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff888028c69e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000d18fad0 R08: ffffffff90da362f R09: 1ffffffff21b46c5 R10: dffffc0000000000 R11: fffffbfff21b46c6 R12: 1ffff92001a31f44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92001a31f65 smp_call_function_single+0x352/0x580 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948 __do_sys_perf_event_open kernel/events/core.c:12900 [inline] __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12552 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f18a9b8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f18aaa40038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f18a9db5fa0 RCX: 00007f18a9b8ebe9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480 RBP: 00007f18a9c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f18a9db6038 R14: 00007f18a9db5fa0 R15: 00007fff32c85bc8