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 1C559C606C3 for ; Mon, 8 Jul 2019 15:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E51D3216C4 for ; Mon, 8 Jul 2019 15:30:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599825; bh=EnjuQiri8fxKmmSfNGNWGp7FDP1+lvBIO/dhJrFiXVU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZEWLcBLX5nF/mzYtzBVys/4dfqNN7T+R9YnxiUPHZ4uDT3KD6ZqxMLNMvzcf3BDpp qGE6U1mFP/nJMWElMsFKo96Pm0n00/M4riesKwtaT7s/OuXfBXGqC3OS1OSU425MN/ T6ps42r4MZuzG+6Nky05RkgHTnH+0jtVoXqrFXmA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732095AbfGHPaX (ORCPT ); Mon, 8 Jul 2019 11:30:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:59312 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389558AbfGHPaV (ORCPT ); Mon, 8 Jul 2019 11:30:21 -0400 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 AA15F20665; Mon, 8 Jul 2019 15:30:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599820; bh=EnjuQiri8fxKmmSfNGNWGp7FDP1+lvBIO/dhJrFiXVU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fJZrS3ngWOqGRzilI8W3KW4AX1odMzvA+2OlAzrCEe5OcNrwIlFY8nM5VzjMkDGj/ EnCD7vTf9e7X9+aX+ShVI3KsiYEmevHwYVmAdLvzBCWcqMi0M5S5AetpkwxCEFuF2r jhX861oFqtWR2QCEbSgJHsCHU/O2Lk0/hqCM6zog= 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 Subject: [PATCH 4.19 46/90] ALSA: line6: Fix write on zero-sized buffer Date: Mon, 8 Jul 2019 17:13:13 +0200 Message-Id: <20190708150524.894237413@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150521.829733162@linuxfoundation.org> References: <20190708150521.829733162@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 Cc: Signed-off-by: Takashi Iwai 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 @@ -560,6 +560,11 @@ int line6_init_pcm(struct usb_line6 *lin line6pcm->max_packet_size_out = usb_maxpacket(line6->usbdev, usb_sndisocpipe(line6->usbdev, ep_write), 1); + if (!line6pcm->max_packet_size_in || !line6pcm->max_packet_size_out) { + 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);