From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F9CAC43441 for ; Fri, 16 Nov 2018 22:09:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66E7D208E3 for ; Fri, 16 Nov 2018 22:09:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 66E7D208E3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729742AbeKQIXP (ORCPT ); Sat, 17 Nov 2018 03:23:15 -0500 Received: from mail-io1-f71.google.com ([209.85.166.71]:35858 "EHLO mail-io1-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728024AbeKQIXO (ORCPT ); Sat, 17 Nov 2018 03:23:14 -0500 Received: by mail-io1-f71.google.com with SMTP id w5so688719iom.3 for ; Fri, 16 Nov 2018 14:09:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=q/Xy4u37esu6jonFyOoEAOaLEXNv1nCncNvMM6VHDeA=; b=gX4BWJFfJ77w8x+sQA/QEr+5qoh6LkhhUOq1xNKFfnetbZi/YgTE6kIoI5CwQ+h/A1 TGcTqDsfGmcHzaEOOL23J4PXFIaMHc9RnT/e1ynNMdxTGO5U8jyzkjol68PplrgOJwoW Uj145Agg3Piu5zMmqpj5sl0pAFCcOrWo5dotr6PYizANvfWvJ+7f9PfVe1/whzhRhRGw Zse7mxoaYFNSJaxAdVoNfgRRyxL7OgbfEL3/baMslSrGsUtYikCIf7pA0EMSMXGiDCl3 F7fzoYrGgsbC1ScBqJKW/ZSU4731Oso8nfPP32JzC5oNJj1coBHUH7k5uZgNozTSCEh3 TRKw== X-Gm-Message-State: AA+aEWaEJsbW4cZZvHgfMIvrkBaiRYrOQW08Hxd7TFR1eFGNq/zJCV1l C91eJtYvuwicAw5jL9vbsbKldN1RJXJ/JZ5DL1pvfBBgiq22 X-Google-Smtp-Source: AFSGD/UWaxXWPaivkO2AdjDx+hZg3djPXl1uBYRfFt1IorxBLesVhcJCbv1VkaFb6w8ALwnPfcJbyn2AzYmp5sFmvX0RIb10r+PS MIME-Version: 1.0 X-Received: by 2002:a24:6908:: with SMTP id e8-v6mr48646itc.7.1542406144215; Fri, 16 Nov 2018 14:09:04 -0800 (PST) Date: Fri, 16 Nov 2018 14:09:04 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000535c70057acf6a48@google.com> Subject: KMSAN: kernel-infoleak in kvm_arch_vcpu_ioctl From: syzbot To: bp@alien8.de, hpa@zytor.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, pbonzini@redhat.com, rkrcmar@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 006aa39cddee kmsan: don't instrument fixup_bad_iret() git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=101dcb0b400000 kernel config: https://syzkaller.appspot.com/x/.config?x=f388ea1732f3c473 dashboard link: https://syzkaller.appspot.com/bug?extid=cfbc368e283d381f8cef compiler: clang version 8.0.0 (trunk 343298) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c56fbd400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153c8a47400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+cfbc368e283d381f8cef@syzkaller.appspotmail.com IPVS: ftp: loaded support on port[0] = 21 L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. ================================================================== BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 lib/usercopy.c:31 CPU: 0 PID: 6697 Comm: syz-executor853 Not tainted 4.20.0-rc2+ #85 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x32d/0x480 lib/dump_stack.c:113 kmsan_report+0x19f/0x300 mm/kmsan/kmsan.c:911 kmsan_internal_check_memory+0x35b/0x3b0 mm/kmsan/kmsan.c:993 kmsan_copy_to_user+0x7c/0xe0 mm/kmsan/kmsan_hooks.c:552 _copy_to_user+0x19a/0x230 lib/usercopy.c:31 copy_to_user include/linux/uaccess.h:183 [inline] kvm_vcpu_ioctl_enable_cap arch/x86/kvm/x86.c:3834 [inline] kvm_arch_vcpu_ioctl+0x5dee/0x7680 arch/x86/kvm/x86.c:4132 kvm_vcpu_ioctl+0xca3/0x1f90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2748 do_vfs_ioctl+0xfbc/0x2f70 fs/ioctl.c:46 ksys_ioctl fs/ioctl.c:713 [inline] __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x4471b9 Code: e8 fc b9 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 3b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1e22946da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006f0038 RCX: 00000000004471b9 RDX: 0000000020000000 RSI: 000000004068aea3 RDI: 0000000000000005 RBP: 00000000006f0030 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006f003c R13: 6d766b2f7665642f R14: 00007f1e229479c0 R15: 00000000000003e8 Local variable description: ----__pu_val@kvm_arch_vcpu_ioctl Variable was created at: kvm_arch_vcpu_ioctl+0x29d/0x7680 arch/x86/kvm/x86.c:3848 kvm_vcpu_ioctl+0xca3/0x1f90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2748 Bytes 0-1 of 2 are uninitialized Memory access of size 2 starts at ffff8881967ffbb0 Data copied to user address 0000000000706000 ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches