From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752257AbdLGHty (ORCPT ); Thu, 7 Dec 2017 02:49:54 -0500 Received: from mail-ot0-f196.google.com ([74.125.82.196]:44905 "EHLO mail-ot0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752182AbdLGHtw (ORCPT ); Thu, 7 Dec 2017 02:49:52 -0500 X-Google-Smtp-Source: AGs4zMZOahMcRnJAV/heID7OFW8bFaT1WjqQNnor5BeGwZ8D7WhgxbHZ9RepAwhSfZ7rVnhatj4LkvbLl6QKvr1MkdU= MIME-Version: 1.0 In-Reply-To: References: <001a1143d526c5b1aa055f9d604c@google.com> From: =?UTF-8?B?6JOd5aSp5a6H?= Date: Thu, 7 Dec 2017 15:49:51 +0800 Message-ID: Subject: Re: WARNING in x86_emulate_insn To: Dmitry Vyukov Cc: Wanpeng Li , 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 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... 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