rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2666 jiffies s: 305585 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: 20272 Comm: syz.6.12564 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data kernel/kcov.c:244 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x4/0x80 kernel/kcov.c:299 Code: 77 1e 49 ff c0 4c 89 02 48 c7 44 0a 08 06 00 00 00 48 89 7c 0a 10 48 89 74 0a 18 48 89 44 0a 20 c3 0f 1f 44 00 00 48 8b 04 24 <65> 48 8b 15 c4 4b 80 7e 65 8b 0d c5 4b 80 7e 81 e1 00 01 ff 00 74 RSP: 0018:ffffc900001e0540 EFLAGS: 00000047 RAX: ffffffff818e73bb RBX: ffff8880b8f3bbf0 RCX: ffffffff818e739f RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 0000000000000001 R08: ffffffff8e200f6f R09: 1ffffffff1c401ed R10: dffffc0000000000 R11: fffffbfff1c401ee R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110171e7782 FS: 00007f2ad18cd6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000004000 CR3: 000000007a214000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: variable_test_bit arch/x86/include/asm/bitops.h:228 [inline] arch_test_bit arch/x86/include/asm/bitops.h:240 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] cpumask_test_cpu include/linux/cpumask.h:444 [inline] cpu_online include/linux/cpumask.h:1030 [inline] irq_work_queue_on+0x8b/0x260 kernel/irq_work.c:134 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] __perf_event_output kernel/events/core.c:7741 [inline] perf_event_output_forward+0x271/0x2f0 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:variable_ffs arch/x86/include/asm/bitops.h:319 [inline] RIP: 0010:handle_softirqs+0x1b7/0x910 kernel/softirq.c:584 Code: 89 7c 24 2c 0f b7 db 48 c7 c7 80 0d 8b 8a e8 e0 af db 08 65 66 c7 05 66 62 b4 7e 00 00 e8 b1 47 39 00 fb 49 c7 c5 c0 a0 80 8c <89> 5c 24 34 b8 ff ff ff ff 0f bc 44 24 34 41 89 c6 41 ff c6 0f 84 RSP: 0018:ffffc900001e0e20 EFLAGS: 00000282 RAX: 39f9bff6de360400 RBX: 0000000000000200 RCX: 39f9bff6de360400 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adee1a0 RBP: ffffc900001e0f30 R08: ffffffff90af22df R09: 1ffffffff215e45b R10: dffffc0000000000 R11: fffffbfff215e45c R12: dffffc0000000000 R13: ffffffff8c80a0c0 R14: ffff888023f11e00 R15: 000000000000000a __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_read_unlock_special+0x0/0x510 kernel/rcu/tree_plugin.h:630 Code: f6 5c 66 00 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 94 49 89 fd 4c 89 f7 e8 dc 5c 66 00 4c 89 ef eb 84 0f 1f 80 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 RSP: 0018:ffffc90006017518 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff888023f1223c RCX: 0000000000080000 RDX: ffffc90019060000 RSI: 0000000000013d31 RDI: ffff888023f11e00 RBP: ffffc90006017870 R08: ffff88801c1790cf R09: 1ffff1100382f219 R10: dffffc0000000000 R11: ffffed100382f21a R12: 1ffff110047e2447 R13: ffff888061dff110 R14: ffff888023f12240 R15: dffffc0000000000 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] page_ext_put+0x91/0xb0 mm/page_ext.c:182 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline] copy_present_pte mm/memory.c:1000 [inline] copy_pte_range mm/memory.c:1091 [inline] copy_pmd_range mm/memory.c:1177 [inline] copy_pud_range mm/memory.c:1214 [inline] copy_p4d_range mm/memory.c:1238 [inline] copy_page_range+0x2586/0x3a60 mm/memory.c:1332 dup_mmap kernel/fork.c:703 [inline] dup_mm kernel/fork.c:1547 [inline] copy_mm+0xeb0/0x1680 kernel/fork.c:1596 copy_process+0x19a6/0x40c0 kernel/fork.c:2357 kernel_clone+0x24b/0x900 kernel/fork.c:2764 __do_sys_clone kernel/fork.c:2905 [inline] __se_sys_clone kernel/fork.c:2889 [inline] __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2889 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: 0033:0x7f2ad099ce59 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:00007f2ad18ccfd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f2ad0c16180 RCX: 00007f2ad099ce59 RDX: 0000200000000740 RSI: 0000200000000990 RDI: 0000000000001000 RBP: 00007f2ad0a32e6f R08: 00002000000026c0 R09: 00002000000026c0 R10: 0000200000000780 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f2ad0c16218 R14: 00007f2ad0c16180 R15: 00007ffe1e3346e8