------------[ cut here ]------------ WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#0: syz.0.17/6054 Modules linked in: CPU: 0 UID: 0 PID: 6054 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049 Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 c0 92 c2 9a e8 00 41 85 00 b8 01 00 00 00 87 05 55 f3 1e 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 74 fe 88 90 48 81 fd 80 46 3d 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000007df0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81a39f60 RDX: fffffbfff3585258 RSI: 0000000000000004 RDI: ffffffff9ac292c0 RBP: ffffffff8e3d4680 R08: 0000000000000001 R09: fffffbfff3585258 R10: 0000000000000003 R11: ffff88807be654b0 R12: 1ffffffff1c02250 R13: 0000000000000246 R14: ffffffff8e3d4680 R15: ffff8880b843bc52 FS: 0000555572a50500(0000) GS:ffff8881248f1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000000b CR3: 0000000073a26000 CR4: 00000000003526f0 Call Trace: rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline] rcu_core+0x4cf/0x15f0 kernel/rcu/tree.c:2852 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:vcpu_enter_guest arch/x86/kvm/x86.c:11448 [inline] RIP: 0010:vcpu_run+0x3197/0x5a80 arch/x86/kvm/x86.c:11648 Code: b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 d9 23 00 00 41 c6 86 32 0c 00 00 01 e8 f1 43 85 00 fb 48 8b 95 98 fe ff ff <48> b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 9b 23 RSP: 0018:ffffc90003577a80 EFLAGS: 00000206 RAX: 0000000002cf6709 RBX: ffff88801cb08c32 RCX: 0000000000000006 RDX: ffff88801cb09d08 RSI: ffffffff8dacf6fe RDI: ffffffff8bf2b580 RBP: ffffc90003577c10 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9088cdd7 R11: 0000000000000000 R12: dffffc0000000000 R13: 0001000000000000 R14: ffff88801cb08000 R15: ffff88801cb08038 kvm_arch_vcpu_ioctl_run+0xfd3/0x1860 arch/x86/kvm/x86.c:11993 kvm_vcpu_ioctl+0x76d/0x16d0 virt/kvm/kvm_main.c:4492 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec1f98f749 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:00007fff00e2df88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fec1fbe5fa0 RCX: 00007fec1f98f749 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007fec1fa13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fec1fbe5fa0 R14: 00007fec1fbe5fa0 R15: 0000000000000003 ---------------- Code disassembly (best guess): 0: b6 04 mov $0x4,%dh 2: 02 48 89 add -0x77(%rax),%cl 5: da 83 e2 07 38 d0 fiaddl -0x2fc7f81e(%rbx) b: 7f 08 jg 0x15 d: 84 c0 test %al,%al f: 0f 85 d9 23 00 00 jne 0x23ee 15: 41 c6 86 32 0c 00 00 movb $0x1,0xc32(%r14) 1c: 01 1d: e8 f1 43 85 00 call 0x854413 22: fb sti 23: 48 8b 95 98 fe ff ff mov -0x168(%rbp),%rdx * 2a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 31: fc ff df 34: 48 c1 ea 03 shr $0x3,%rdx 38: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 3c: 0f .byte 0xf 3d: 85 .byte 0x85 3e: 9b fwait 3f: 23 .byte 0x23