Hello, I've got the following warning while running syzkaller fuzzer: WARNING: CPU: 2 PID: 13257 at arch/x86/kvm/vmx.c:8633 vmx_handle_exit+0x262b/0x38b0 arch/x86/kvm/vmx.c:8633 vmx: unexpected exit reason 0xb CPU: 2 PID: 13257 Comm: syz-executor7 Not tainted 4.10.0-rc1+ #118 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0x292/0x3a2 lib/dump_stack.c:51 panic+0x1cb/0x3a9 kernel/panic.c:179 __warn+0x1c4/0x1e0 kernel/panic.c:539 warn_slowpath_fmt+0xc5/0x100 kernel/panic.c:562 vmx_handle_exit+0x262b/0x38b0 arch/x86/kvm/vmx.c:8633 vcpu_enter_guest arch/x86/kvm/x86.c:6884 [inline] vcpu_run arch/x86/kvm/x86.c:6943 [inline] kvm_arch_vcpu_ioctl_run+0xf3d/0x45f0 arch/x86/kvm/x86.c:7101 kvm_vcpu_ioctl+0x673/0x1120 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2569 vfs_ioctl fs/ioctl.c:43 [inline] do_vfs_ioctl+0x1bf/0x1780 fs/ioctl.c:683 SYSC_ioctl fs/ioctl.c:698 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x4438a9 RSP: 002b:00007f935aa2fb58 EFLAGS: 00000286 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 00000000004438a9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000015 RBP: 00000000006ddb30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000700000 R13: 0000000000000006 R14: 0000000000000015 R15: 0000000020014000 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Exit reason 0xb is GETSEC instruction. This does not look harmful as it is handled as #UD. But I think we should print a single line message regarding non-emulated instruction as in other cases, just to not scare cloud admins and to make syzkaller ignore it. FTR, a raw reproducer is here: https://gist.githubusercontent.com/dvyukov/c762f6ea04ebbba49cdee0a6caca31b4/raw/f21deb04cdc70ae74100c12447d71bb0cd2025c7/gistfile1.txt -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
