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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 B6478C43603 for ; Wed, 4 Dec 2019 14:51:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 924762073C for ; Wed, 4 Dec 2019 14:51:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728048AbfLDOvA (ORCPT ); Wed, 4 Dec 2019 09:51:00 -0500 Received: from mx2.suse.de ([195.135.220.15]:60940 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727850AbfLDOvA (ORCPT ); Wed, 4 Dec 2019 09:51:00 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6A833AECA; Wed, 4 Dec 2019 14:50:58 +0000 (UTC) Date: Wed, 04 Dec 2019 15:50:58 +0100 Message-ID: From: Takashi Iwai To: syzbot Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, perex@perex.cz, syzkaller-bugs@googlegroups.com, tiwai@suse.com Subject: Re: KASAN: slab-out-of-bounds Read in linear_transfer (3) In-Reply-To: <000000000000055ac40598dc8d46@google.com> References: <000000000000055ac40598dc8d46@google.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 04 Dec 2019 09:25:09 +0100, syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 76bb8b05 Merge tag 'kbuild-v5.5' of git://git.kernel.org/p.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1416a90ee00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=dd226651cb0f364b > dashboard link: https://syzkaller.appspot.com/bug?extid=f153bde47a62e0b05f83 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10fe9e41e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1522042ae00000 > > The bug was bisected to: > > commit 65766ee0bf7fe8b3be80e2e1c3ef54ad59b29476 > Author: Takashi Iwai > Date: Fri Nov 9 10:59:45 2018 +0000 > > ALSA: oss: Use kvzalloc() for local buffer allocations FYI, this bisection result is bogus; before this commit, the buffer was allocated via vmalloc and KASAN check was skipped. Now with kvmalloc(), it goes with kmalloc which has a proper check, and the problem surfaced since this commit. The real culprit is a potential buffer overflow in the OSS plugin chain. I submitted the fix patch now. Takashi