From patchwork Tue Jun 5 18:08:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 10449055 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 109F760234 for ; Tue, 5 Jun 2018 18:10:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F12032999D for ; Tue, 5 Jun 2018 18:10:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E266229999; Tue, 5 Jun 2018 18:10:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6B8CD29999 for ; Tue, 5 Jun 2018 18:10:41 +0000 (UTC) Received: from localhost ([::1]:48420 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQGPo-0007q5-Gm for patchwork-qemu-devel@patchwork.kernel.org; Tue, 05 Jun 2018 14:10:40 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59344) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQGO1-0006oF-9Z for qemu-devel@nongnu.org; Tue, 05 Jun 2018 14:08:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQGO0-0000Zs-8z for qemu-devel@nongnu.org; Tue, 05 Jun 2018 14:08:49 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48658 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fQGO0-0000ZQ-3t for qemu-devel@nongnu.org; Tue, 05 Jun 2018 14:08:48 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A7EFC40BC078; Tue, 5 Jun 2018 18:08:47 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4008F2026DEF; Tue, 5 Jun 2018 18:08:44 +0000 (UTC) From: P J P To: Qemu Developers Date: Tue, 5 Jun 2018 23:38:35 +0530 Message-Id: <20180605180836.21485-2-ppandit@redhat.com> In-Reply-To: <20180605180836.21485-1-ppandit@redhat.com> References: <20180605180836.21485-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Tue, 05 Jun 2018 18:08:47 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Tue, 05 Jun 2018 18:08:47 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'ppandit@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH 1/2] slirp: correct size computation while concatenating mbuf X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Samuel Thibault , Prasad J Pandit , Jan Kiszka Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit While reassembling incoming fragmented datagrams, 'm_cat' routine extends the 'mbuf' buffer, if it has insufficient room. It computes a wrong buffer size, which leads to overwriting adjacent heap buffer area. Correct this size computation in m_cat. Reported-by: ZDI Disclosures Signed-off-by: Prasad J Pandit --- slirp/mbuf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/slirp/mbuf.c b/slirp/mbuf.c index 5ff24559fd..0f45abd917 100644 --- a/slirp/mbuf.c +++ b/slirp/mbuf.c @@ -138,7 +138,7 @@ m_cat(struct mbuf *m, struct mbuf *n) * If there's no room, realloc */ if (M_FREEROOM(m) < n->m_len) - m_inc(m,m->m_size+MINCSIZE); + m_inc(m, m->m_len + n->m_len); memcpy(m->m_data+m->m_len, n->m_data, n->m_len); m->m_len += n->m_len; @@ -158,12 +158,12 @@ m_inc(struct mbuf *m, int size) if (m->m_flags & M_EXT) { datasize = m->m_data - m->m_ext; - m->m_ext = g_realloc(m->m_ext, size); + m->m_ext = g_realloc(m->m_ext, size + datasize); m->m_data = m->m_ext + datasize; } else { char *dat; datasize = m->m_data - m->m_dat; - dat = g_malloc(size); + dat = g_malloc(size + datasize); memcpy(dat, m->m_dat, m->m_size); m->m_ext = dat; @@ -171,7 +171,7 @@ m_inc(struct mbuf *m, int size) m->m_flags |= M_EXT; } - m->m_size = size; + m->m_size = size + datasize; }