Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752035AbdLGHwY (ORCPT ); Thu, 7 Dec 2017 02:52:24 -0500 Received: from mail-ot0-f194.google.com ([74.125.82.194]:40613 "EHLO mail-ot0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750857AbdLGHwW (ORCPT ); Thu, 7 Dec 2017 02:52:22 -0500 X-Google-Smtp-Source: AGs4zMZtUoYGpvmWYridwwnt/7j8YrEModdr9SCoJ35evWnWF4bnxYuh049JgmIhPlI0rTKjI8Df0ZmMve0jV7F3H/A= MIME-Version: 1.0 In-Reply-To: References: <001a1143d526c5b1aa055f9d604c@google.com> From: Wanpeng Li Date: Thu, 7 Dec 2017 15:52:21 +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 vB77qTbi021173 Content-Length: 5382 Lines: 121 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. 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