From nobody Mon Feb 9 10:28:06 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 152822223276334.90237331770527; Tue, 5 Jun 2018 11:10:32 -0700 (PDT) Received: from localhost ([::1]:48420 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQGPY-0007q5-32 for importer@patchew.org; Tue, 05 Jun 2018 14:10:24 -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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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); =20 memcpy(m->m_data+m->m_len, n->m_data, n->m_len); m->m_len +=3D n->m_len; @@ -158,12 +158,12 @@ m_inc(struct mbuf *m, int size) =20 if (m->m_flags & M_EXT) { datasize =3D m->m_data - m->m_ext; - m->m_ext =3D g_realloc(m->m_ext, size); + m->m_ext =3D g_realloc(m->m_ext, size + datasize); m->m_data =3D m->m_ext + datasize; } else { char *dat; datasize =3D m->m_data - m->m_dat; - dat =3D g_malloc(size); + dat =3D g_malloc(size + datasize); memcpy(dat, m->m_dat, m->m_size); =20 m->m_ext =3D dat; @@ -171,7 +171,7 @@ m_inc(struct mbuf *m, int size) m->m_flags |=3D M_EXT; } =20 - m->m_size =3D size; + m->m_size =3D size + datasize; =20 } =20 --=20 2.17.1