From nobody Mon Apr 29 19:50:55 2024 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 Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1510818809050630.0683995222654; Wed, 15 Nov 2017 23:53:29 -0800 (PST) Received: from localhost ([::1]:39447 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFEz2-0005Tg-V4 for importer@patchew.org; Thu, 16 Nov 2017 02:53:12 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37394) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFEy7-0005AJ-0U for qemu-devel@nongnu.org; Thu, 16 Nov 2017 02:52:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eFEy3-0005lX-Uf for qemu-devel@nongnu.org; Thu, 16 Nov 2017 02:52:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43646) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eFEy3-0005kd-O3 for qemu-devel@nongnu.org; Thu, 16 Nov 2017 02:52:11 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7266861462; Thu, 16 Nov 2017 07:52:10 +0000 (UTC) Received: from localhost.localdomain (vpn2-54-19.bne.redhat.com [10.64.54.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E37BB173D1; Thu, 16 Nov 2017 07:52:02 +0000 (UTC) From: P J P To: Qemu Developers Date: Thu, 16 Nov 2017 13:21:55 +0530 Message-Id: <20171116075155.22378-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 16 Nov 2017 07:52:10 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v1] ps2: check PS2Queue pointers in post_load routine 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: Prasad J Pandit , Cyrille Chatras , "Dr . David Alan Gilbert" , Gerd Hoffmann , Paolo Bonzini 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 During Qemu guest migration, a destination process invokes ps2 post_load function. In that, if 'rptr' and 'count' values were invalid, it could lead to OOB access or infinite loop issue. Add check to avoid it. Reported-by: Cyrille Chatras Signed-off-by: Prasad J Pandit --- hw/input/ps2.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) Update: avoid changing field type, add range check on values -> https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg02815.html diff --git a/hw/input/ps2.c b/hw/input/ps2.c index f388a23c8e..de171a28dd 100644 --- a/hw/input/ps2.c +++ b/hw/input/ps2.c @@ -1225,24 +1225,21 @@ static void ps2_common_reset(PS2State *s) static void ps2_common_post_load(PS2State *s) { PS2Queue *q =3D &s->queue; - int size; - int i; - int tmp_data[PS2_QUEUE_SIZE]; + uint8_t i, size; + uint8_t tmp_data[PS2_QUEUE_SIZE]; =20 /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */ - size =3D q->count > PS2_QUEUE_SIZE ? 0 : q->count; + size =3D (q->count < 0 || q->count > PS2_QUEUE_SIZE) ? 0 : q->count; =20 /* move the queue elements to the start of data array */ - if (size > 0) { - for (i =3D 0; i < size; i++) { - /* move the queue elements to the temporary buffer */ - tmp_data[i] =3D q->data[q->rptr]; - if (++q->rptr =3D=3D 256) { - q->rptr =3D 0; - } + for (i =3D 0; i < size; i++) { + if (q->rptr < 0 || q->rptr >=3D sizeof(q->data)) { + q->rptr =3D 0; } - memcpy(q->data, tmp_data, size); + tmp_data[i] =3D q->data[q->rptr++]; } + memcpy(q->data, tmp_data, size); + /* reset rptr/wptr/count */ q->rptr =3D 0; q->wptr =3D size; --=20 2.13.6