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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 D0F65C33CAF for ; Wed, 22 Jan 2020 09:31:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E24E2071E for ; Wed, 22 Jan 2020 09:31:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685500; bh=tLo/PZQiGCZ4iDPRBI4rrsteQuQ+bsj4OpwZeKsyMNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oiy7Q2dXlFvlXEKCAlF8BOJ7eJDoWQxXXJUVGB1W2TbbW7mM3jyAOe+qFLIESqL8J kZg3jEKKMbhgoKATSl06sI9wZhRAao5gXXpShjvK1/UmwN1LEXSEAdVKC8QpiuOBpa TYuJb/8+o08beWw2qQgUSFIXFgOAFVnxbFirqJuc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729822AbgAVJbi (ORCPT ); Wed, 22 Jan 2020 04:31:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:43786 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729762AbgAVJbd (ORCPT ); Wed, 22 Jan 2020 04:31:33 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E998024673; Wed, 22 Jan 2020 09:31:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685493; bh=tLo/PZQiGCZ4iDPRBI4rrsteQuQ+bsj4OpwZeKsyMNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eAdy0ychJ+fyhoyFkV+tL9az24e5Dm2xfd6yXvtzzZhZCD2pVt2Go0yV6iBX+laY2 Lih8EO5ds0UBkhlPRXrzu1Q7VcNgO10ExOZhPN9RlaQw1uOlPO4Ngfmq2MAh6dx7iv PEP7rsmBqDDhGO2+WNh3DWwa4g81IGRZGpSG7UJE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+219f00fb49874dcaea17@syzkaller.appspotmail.com, Takashi Iwai , Ben Hutchings Subject: [PATCH 4.4 09/76] ALSA: line6: Fix write on zero-sized buffer Date: Wed, 22 Jan 2020 10:28:25 +0100 Message-Id: <20200122092752.509707971@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092751.587775548@linuxfoundation.org> References: <20200122092751.587775548@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takashi Iwai commit 3450121997ce872eb7f1248417225827ea249710 upstream. LINE6 drivers allocate the buffers based on the value returned from usb_maxpacket() calls. The manipulated device may return zero for this, and this results in the kmalloc() with zero size (and it may succeed) while the other part of the driver code writes the packet data with the fixed size -- which eventually overwrites. This patch adds a simple sanity check for the invalid buffer size for avoiding that problem. Reported-by: syzbot+219f00fb49874dcaea17@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai [bwh: Backported to 4.4: Driver doesn't support asymmetrical packet sizes, so only check snd_line6_pcm::max_packet_size] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- sound/usb/line6/pcm.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/sound/usb/line6/pcm.c +++ b/sound/usb/line6/pcm.c @@ -529,6 +529,11 @@ int line6_init_pcm(struct usb_line6 *lin usb_rcvisocpipe(line6->usbdev, ep_read), 0), usb_maxpacket(line6->usbdev, usb_sndisocpipe(line6->usbdev, ep_write), 1)); + if (!line6pcm->max_packet_size) { + dev_err(line6pcm->line6->ifcdev, + "cannot get proper max packet size\n"); + return -EINVAL; + } spin_lock_init(&line6pcm->out.lock); spin_lock_init(&line6pcm->in.lock);