From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752695AbdLGKkj (ORCPT ); Thu, 7 Dec 2017 05:40:39 -0500 Received: from mail-oi0-f65.google.com ([209.85.218.65]:45543 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750913AbdLGKkh (ORCPT ); Thu, 7 Dec 2017 05:40:37 -0500 X-Google-Smtp-Source: AGs4zMZQdwKV+txyVkVgyiXyxzXaT2AcxeAxJhYomwmFquLXoXFXv1YubmO6ITLSLrhcXLqfZxwpEBRSSwfyt8nGDeE= MIME-Version: 1.0 In-Reply-To: References: <001a1143d526c5b1aa055f9d604c@google.com> From: Wanpeng Li Date: Thu, 7 Dec 2017 18:40:35 +0800 Message-ID: Subject: Re: WARNING in x86_emulate_insn To: =?UTF-8?B?6JOd5aSp5a6H?= Cc: Dmitry Vyukov , syzbot , "H. Peter Anvin" , kvm , "linux-kernel@vger.kernel.org" , Ingo Molnar , Paolo Bonzini , Radim Krcmar , syzkaller-bugs@googlegroups.com, Thomas Gleixner , "the arch/x86 maintainers" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB7Aeilx023019 2017-12-07 15:52 GMT+08:00 Wanpeng Li : > 2017-12-07 15:49 GMT+08:00 蓝天宇 : >> Hi Dmitry: >> I tried to reproduce the issue via syz-execprog with attached >> reproducer on latest linux-next but it causes VM-entry failure due to >> invalid guest state... > > Because rflags is 0 in his program. You can set ept=0 and retry. In addition, you can apply this commit https://lkml.org/lkml/2017/12/7/144 before testing. > > Regards, > Wanpeng Li > >> >> 2017-12-07 14:25 GMT+08:00 Dmitry Vyukov : >>> On Thu, Dec 7, 2017 at 1:44 AM, Wanpeng Li wrote: >>>> 2017-12-06 4:07 GMT+08:00 syzbot >>>> : >>>>> Hello, >>>>> >>>>> syzkaller hit the following crash on >>>>> fb20eb9d798d2f4c1a75b7fe981d72dfa8d7270d >>>>> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master >>>>> compiler: gcc (GCC) 7.1.1 20170620 >>>>> .config is attached >>>>> Raw console output is attached. >>>>> >>>>> syzkaller reproducer is attached. See https://goo.gl/kgGztJ >>>>> for information about syzkaller reproducers >>>>> >>>> >>>> Is there a c program to reproduce? >>> >>> No, syzbot does not hide reproducers. See the referenced doc for >>> details: https://github.com/google/syzkaller/blob/master/docs/syzbot.md#syzkaller-reproducers >>> >>> >>>> Regards, >>>> Wanpeng Li >>>> >>>>> >>>>> kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu >>>>> WARNING: CPU: 1 PID: 3526 at arch/x86/kvm/emulate.c:5654 >>>>> x86_emulate_insn+0xd01/0x3cf0 arch/x86/kvm/emulate.c:5654 >>>>> Kernel panic - not syncing: panic_on_warn set ... >>>>> >>>>> CPU: 1 PID: 3526 Comm: syz-executor4 Not tainted 4.15.0-rc1-next-20171201+ >>>>> #57 >>>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >>>>> Google 01/01/2011 >>>>> Call Trace: >>>>> __dump_stack lib/dump_stack.c:17 [inline] >>>>> dump_stack+0x194/0x257 lib/dump_stack.c:53 >>>>> panic+0x1e4/0x41c kernel/panic.c:183 >>>>> __warn+0x1dc/0x200 kernel/panic.c:547 >>>>> report_bug+0x211/0x2d0 lib/bug.c:184 >>>>> fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177 >>>>> fixup_bug arch/x86/kernel/traps.c:246 [inline] >>>>> do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295 >>>>> do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 >>>>> invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1066 >>>>> RIP: 0010:x86_emulate_insn+0xd01/0x3cf0 arch/x86/kvm/emulate.c:5654 >>>>> RSP: 0018:ffff8801d0fff3e8 EFLAGS: 00010293 >>>>> RAX: ffff8801d17b60c0 RBX: 1ffff1003a1ffe86 RCX: ffffffff81154351 >>>>> RDX: 0000000000000000 RSI: ffffffffffffffff RDI: ffff8801d0b5b5c8 >>>>> RBP: ffff8801d0fff4f8 R08: ffff8801d0b58d80 R09: ffffffff85224da0 >>>>> R10: 0000000000000001 R11: ffffed003a16b6d4 R12: 00000000000000ff >>>>> R13: ffff8801d0b5b5a0 R14: 0000000000000002 R15: ffff8801d0b5b6c3 >>>>> x86_emulate_instruction+0x411/0x1ad0 arch/x86/kvm/x86.c:5771 >>>>> emulate_instruction arch/x86/include/asm/kvm_host.h:1164 [inline] >>>>> complete_emulated_io arch/x86/kvm/x86.c:7190 [inline] >>>>> complete_emulated_pio+0xdd/0x1b0 arch/x86/kvm/x86.c:7201 >>>>> kvm_arch_vcpu_ioctl_run+0x2db2/0x5c60 arch/x86/kvm/x86.c:7305 >>>>> kvm_vcpu_ioctl+0x64c/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2574 >>>>> vfs_ioctl fs/ioctl.c:46 [inline] >>>>> do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686 >>>>> SYSC_ioctl fs/ioctl.c:701 [inline] >>>>> SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 >>>>> entry_SYSCALL_64_fastpath+0x1f/0x96 >>>>> RIP: 0033:0x4529d9 >>>>> RSP: 002b:00007f6b6b2d5c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 >>>>> RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 00000000004529d9 >>>>> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000004 >>>>> RBP: 000000000000039b R08: 0000000000000000 R09: 0000000000000000 >>>>> R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2728 >>>>> R13: 00000000ffffffff R14: 00007f6b6b2d66d4 R15: 0000000000000000 >>>>> Dumping ftrace buffer: >>>>> (ftrace buffer empty) >>>>> Kernel Offset: disabled >>>>> Rebooting in 86400 seconds.. >>>>> >>>>> >>>>> --- >>>>> This bug is generated by a dumb bot. It may contain errors. >>>>> See https://goo.gl/tpsmEJ for details. >>>>> Direct all questions to syzkaller@googlegroups.com. >>>>> Please credit me with: Reported-by: syzbot >>>>> >>>>> syzbot will keep track of this bug report. >>>>> Once a fix for this bug is committed, please reply to this email with: >>>>> #syz fix: exact-commit-title >>>>> If you want to test a patch for this bug, please reply with: >>>>> #syz test: git://repo/address.git branch >>>>> and provide the patch inline or as an attachment. >>>>> To mark this as a duplicate of another syzbot report, please reply with: >>>>> #syz dup: exact-subject-of-another-report >>>>> If it's a one-off invalid bug report, please reply with: >>>>> #syz invalid >>>>> Note: if the crash happens again, it will cause creation of a new bug >>>>> report. >>>>> Note: all commands must start from beginning of the line in the email body. >>>> >>>> -- >>>> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. >>>> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CANRm%2BCw6u-Tvq6M%2B8hFm9UmxyTWsqvrm5L9bzfoTAvEsaeC1-w%40mail.gmail.com. >>>> For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> Best regards >> Tianyu Lan