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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 894E2C433E2 for ; Sun, 12 Jul 2020 21:37:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6649920674 for ; Sun, 12 Jul 2020 21:37:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594589826; bh=LaukERu2pv75LoRhGqzTdKknNVP0Uslzw4bshPJDjGU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=B2CWGCZKR46TU4huxnpOxeo5q61QjraEjkhz4bvGIkIvjsi+crm4z5cD9CusrgGhZ 80bIwPbHv3o1w6XnIbrSVu7b3M+LIIYsMf82r6HLaSEyjNf7fInysZfCQSE4JqAUTC v3uhrw5fQ7nwi4zr/pB2hvryke9uNVSdlGCqCp5g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729469AbgGLVge (ORCPT ); Sun, 12 Jul 2020 17:36:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:42712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729020AbgGLVgd (ORCPT ); Sun, 12 Jul 2020 17:36:33 -0400 Received: from sol.localdomain (c-107-3-166-239.hsd1.ca.comcast.net [107.3.166.239]) (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 229BA20674; Sun, 12 Jul 2020 21:36:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594589793; bh=LaukERu2pv75LoRhGqzTdKknNVP0Uslzw4bshPJDjGU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kyM2cyiEITBrG5oIVpYyR4sxM6ZHAlQtrGYEedEQtuZUVF8OxssMF9d/SiWt2H7Bx W7xyNnYvIxxfOVRxpUNs1t5hO9OZcEQorI5Qbom3a1RV3HcJwby6lDBJU2Fa+riMch TW88A8oZWfecMj0VbvXNhDGfRK9kXwhaKsRQsXSc= Date: Sun, 12 Jul 2020 14:36:31 -0700 From: Eric Biggers To: Peilin Ye Cc: "David S . Miller" , Jakub Kicinski , Navid Emamdoost , Christophe JAILLET , Greg Kroah-Hartman , Dan Carpenter , netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [Linux-kernel-mentees] [PATCH net] qrtr: Fix ZERO_SIZE_PTR deref in qrtr_tun_write_iter() Message-ID: <20200712213631.GA809@sol.localdomain> References: <20200712210300.200399-1-yepeilin.cs@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200712210300.200399-1-yepeilin.cs@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Jul 12, 2020 at 05:03:00PM -0400, Peilin Ye wrote: > qrtr_tun_write_iter() is dereferencing `ZERO_SIZE_PTR`s when `from->count` > equals to zero. Fix it by rejecting zero-length kzalloc() requests. > > This patch fixes the following syzbot bug: > > https://syzkaller.appspot.com/bug?id=f56bbe6668873ee245986bbd23312b895fa5a50a > > Reported-by: syzbot+03e343dbccf82a5242a2@syzkaller.appspotmail.com > Signed-off-by: Peilin Ye > --- > net/qrtr/tun.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/qrtr/tun.c b/net/qrtr/tun.c > index 15ce9b642b25..5465e94ba8e5 100644 > --- a/net/qrtr/tun.c > +++ b/net/qrtr/tun.c > @@ -80,6 +80,9 @@ static ssize_t qrtr_tun_write_iter(struct kiocb *iocb, struct iov_iter *from) > ssize_t ret; > void *kbuf; > > + if (!len) > + return -EINVAL; > + > kbuf = kzalloc(len, GFP_KERNEL); > if (!kbuf) > return -ENOMEM; Wasn't this already fixed by: commit 8ff41cc21714704ef0158a546c3c4d07fae2c952 Author: Dan Carpenter Date: Tue Jun 30 14:46:15 2020 +0300 net: qrtr: Fix an out of bounds read qrtr_endpoint_post()