From patchwork Mon Nov 30 07:38:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 549878 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3416F140180 for ; Mon, 30 Nov 2015 18:40:10 +1100 (AEDT) Received: from localhost ([::1]:39363 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3J4C-0007GL-BM for incoming@patchwork.ozlabs.org; Mon, 30 Nov 2015 02:40:08 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47021) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3J3H-00064d-Tg for qemu-devel@nongnu.org; Mon, 30 Nov 2015 02:39:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a3J3H-00020A-0O for qemu-devel@nongnu.org; Mon, 30 Nov 2015 02:39:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49430) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3J3G-000202-RI; Mon, 30 Nov 2015 02:39:10 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 84A2E42E5CF; Mon, 30 Nov 2015 07:39:10 +0000 (UTC) Received: from jason-ThinkPad-T430s.redhat.com (vpn1-4-212.pek2.redhat.com [10.72.4.212]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tAU7cxAh024359; Mon, 30 Nov 2015 02:39:06 -0500 From: Jason Wang To: jasowang@redhat.com, qemu-devel@nongnu.org Date: Mon, 30 Nov 2015 15:38:23 +0800 Message-Id: <1448869103-16281-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1448869103-16281-1-git-send-email-jasowang@redhat.com> References: <1448869103-16281-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Prasad J Pandit , qemu-stable@nongnu.org Subject: [Qemu-devel] [PATCH for 2.5 2/2] pcnet: fix rx buffer overflow(CVE-2015-7512) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Backends could provide a packet whose length is greater than buffer size. Check for this and truncate the packet to avoid rx buffer overflow in this case. Cc: Prasad J Pandit Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang Reviewed-by: Michael S. Tsirkin --- hw/net/pcnet.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c index 309c40b..1f4a3db 100644 --- a/hw/net/pcnet.c +++ b/hw/net/pcnet.c @@ -1064,6 +1064,12 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_) int pktcount = 0; if (!s->looptest) { + if (size > 4092) { +#ifdef PCNET_DEBUG_RMD + fprintf(stderr, "pcnet: truncates rx packet.\n"); +#endif + size = 4092; + } memcpy(src, buf, size); /* no need to compute the CRC */ src[size] = 0;