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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 9CA97C43334 for ; Mon, 3 Sep 2018 01:53:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E5762077C for ; Mon, 3 Sep 2018 01:53:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4E5762077C 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 S1727361AbeICGK4 (ORCPT ); Mon, 3 Sep 2018 02:10:56 -0400 Received: from mail-it0-f71.google.com ([209.85.214.71]:38941 "EHLO mail-it0-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725866AbeICGK4 (ORCPT ); Mon, 3 Sep 2018 02:10:56 -0400 Received: by mail-it0-f71.google.com with SMTP id w196-v6so11038545itb.4 for ; Sun, 02 Sep 2018 18:53:03 -0700 (PDT) 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:in-reply-to:message-id:subject :from:to; bh=pW/7Qx51v4sAzFfbZUihr9divUNHqsDsg5rmKdacwyQ=; b=XQoa2RqidvhyxQDWqABczw5Iu4nwfbnuQA+B6Mlwlf7hZPSpCoG4wJrzqAbYvpI1ep EW9SWlQjvZ3mxG/KPrfCY/ExJa6Y5X4CT/NtCngdtUucyHvkueh/4XC5k4+MVb5ZvtWZ RozrrtrioIbhRaETgm4qdFYaKlRM1h/MUjwjzBZlevhkMWPDqIQGMpDNYdOB/3Eg92Kp X4T6Z3THkdot31XU5Bg1ONLr+tXNp7wlD3axH+u3pJXJzBplyKjCR9FaUM/lotRldo7E lM5ExWDIfpRuxrg7L8rshSM+/yb9eOJpUQz3vk/30BP4etx5pL04m5cHQwDcvU+WFmUF 8khA== X-Gm-Message-State: APzg51AqK4mHRpqhceK8yQImyxUn58ozczse36hsPRQlU74QUSiPNXkQ gztveHRkbjmBdIcUUH4CC6kiA8nX8q1IdVvLCMfaAg01YrRk X-Google-Smtp-Source: ANB0VdaKbrT082Omp7cVc2/NIbX3M6PNFBq272BZrtWYJdQsVw7hhD1sEbX45BQFyK0XYTFOexPg6bl+LGseI9aAKEFFn5cCOBhf MIME-Version: 1.0 X-Received: by 2002:a02:982f:: with SMTP id t44-v6mr10583645jaj.24.1535939583229; Sun, 02 Sep 2018 18:53:03 -0700 (PDT) Date: Sun, 02 Sep 2018 18:53:03 -0700 In-Reply-To: <000000000000feece60574e86f8d@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000004148cf0574edcd45@google.com> Subject: Re: KMSAN: uninit-value in snd_midi_event_encode_byte From: syzbot To: alsa-devel-bounces@alsa-project.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, perex@perex.cz, syzkaller-bugs@googlegroups.com, tiwai@suse.com 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 syzbot has found a reproducer for the following crash on: HEAD commit: 28f0ca98eadf kmsan: don't instrument do_syscall_64() and _.. git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=10556c92400000 kernel config: https://syzkaller.appspot.com/x/.config?x=3431f03869413153 dashboard link: https://syzkaller.appspot.com/bug?extid=194dffdb8b22fc5d207a compiler: clang version 8.0.0 (trunk 339414) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=123a520a400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16068dc1400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+194dffdb8b22fc5d207a@syzkaller.appspotmail.com ================================================================== BUG: KMSAN: uninit-value in snd_midi_event_encode_byte+0x569/0xff0 sound/core/seq/seq_midi_event.c:195 CPU: 1 PID: 1659 Comm: kworker/1:1H Not tainted 4.19.0-rc1+ #40 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_highpri snd_vmidi_output_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x14b/0x190 lib/dump_stack.c:113 kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:956 __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:645 snd_midi_event_encode_byte+0x569/0xff0 sound/core/seq/seq_midi_event.c:195 snd_vmidi_output_work+0x34e/0x5b0 sound/core/seq/seq_virmidi.c:161 process_one_work+0x1605/0x1f40 kernel/workqueue.c:2153 worker_thread+0x11a2/0x2590 kernel/workqueue.c:2296 kthread+0x465/0x4a0 kernel/kthread.c:247 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:416 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline] kmsan_save_stack mm/kmsan/kmsan.c:271 [inline] kmsan_internal_chain_origin+0x128/0x210 mm/kmsan/kmsan.c:573 __msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:482 __snd_rawmidi_transmit_peek sound/core/rawmidi.c:1103 [inline] snd_rawmidi_transmit+0xa75/0xbf0 sound/core/rawmidi.c:1228 snd_vmidi_output_work+0x2ac/0x5b0 sound/core/seq/seq_virmidi.c:159 process_one_work+0x1605/0x1f40 kernel/workqueue.c:2153 worker_thread+0x11a2/0x2590 kernel/workqueue.c:2296 kthread+0x465/0x4a0 kernel/kthread.c:247 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:416 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:181 kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:91 __kmalloc_node+0x7bf/0x11c0 mm/slub.c:3828 kmalloc_node include/linux/slab.h:555 [inline] kvmalloc_node+0x19d/0x3e0 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] snd_rawmidi_runtime_create sound/core/rawmidi.c:132 [inline] open_substream+0x3c8/0xaa0 sound/core/rawmidi.c:276 rawmidi_open_priv+0x347/0x1000 sound/core/rawmidi.c:327 snd_rawmidi_open+0x7d4/0x1120 sound/core/rawmidi.c:424 soundcore_open+0x9be/0xa60 sound/sound_core.c:597 chrdev_open+0xc26/0xdb0 fs/char_dev.c:417 do_dentry_open+0xce6/0x1740 fs/open.c:771 vfs_open+0xaf/0xe0 fs/open.c:880 do_last fs/namei.c:3418 [inline] path_openat+0x1799/0x6870 fs/namei.c:3534 do_filp_open+0x259/0x610 fs/namei.c:3564 do_sys_open+0x630/0x940 fs/open.c:1063 __do_sys_open fs/open.c:1081 [inline] __se_sys_open+0xad/0xc0 fs/open.c:1076 __x64_sys_open+0x4a/0x70 fs/open.c:1076 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 ==================================================================