------------[ cut here ]------------ 1 WARNING: kernel/rcu/tree_stall.h:1048 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048, CPU#0: swapper/0/0 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1048 Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 80 25 43 9b e8 60 17 8c 00 b8 01 00 00 00 87 05 75 44 55 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 64 bb fb 90 48 81 fd 00 14 9f 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000007df0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ede100 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b432580 RBP: ffffffff8e9f1400 R08: 0000000000000001 R09: fffffbfff36864b0 R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1cc1e50 R13: 0000000000000246 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881240e6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000019000 CR3: 0000000056cbf000 CR4: 00000000003526f0 Call Trace: rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1011 [inline] rcu_core+0x2cb/0x10d0 kernel/rcu/tree.c:2892 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 36 a5 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 69 2f 00 fb f4 3c 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e607e10 EFLAGS: 00000242 RAX: 0000000001b6d89d RBX: ffffffff8e691480 RCX: ffffffff8b9c32d5 RDX: 0000000000000000 RSI: ffffffff8e15ae25 RDI: ffffffff8c3e8080 RBP: fffffbfff1cd2290 R08: 0000000000000001 R09: ffffed101708678d R10: ffff8880b8433c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1cc0fc6 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158 ---------------- Code disassembly (best guess): 0: 36 a5 movsl %ds:(%rsi),%es:(%rdi) 2: 02 c3 add %bl,%al 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: 66 90 xchg %ax,%ax 21: 0f 00 2d 63 69 2f 00 verw 0x2f6963(%rip) # 0x2f698b 28: fb sti 29: f4 hlt * 2a: e9 3c 48 03 00 jmp 0x3486b <-- trapping instruction 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop