From patchwork Wed Nov 15 12:46:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 10059327 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 16F946019D for ; Wed, 15 Nov 2017 12:46:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 068E0204FB for ; Wed, 15 Nov 2017 12:46:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EF90B29F75; Wed, 15 Nov 2017 12:46:53 +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=-6.9 required=2.0 tests=BAYES_00,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 5B1E5204FB for ; Wed, 15 Nov 2017 12:46:52 +0000 (UTC) Received: from localhost ([::1]:35854 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eEx5f-0001UQ-SI for patchwork-qemu-devel@patchwork.kernel.org; Wed, 15 Nov 2017 07:46:51 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36603) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eEx57-0001UL-IU for qemu-devel@nongnu.org; Wed, 15 Nov 2017 07:46:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eEx54-00041V-8Q for qemu-devel@nongnu.org; Wed, 15 Nov 2017 07:46:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52902) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eEx54-00040v-2e for qemu-devel@nongnu.org; Wed, 15 Nov 2017 07:46:14 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E51277E421; Wed, 15 Nov 2017 12:46:11 +0000 (UTC) Received: from localhost.localdomain (ovpn-116-111.phx2.redhat.com [10.3.116.111]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 372ED90A19; Wed, 15 Nov 2017 12:46:06 +0000 (UTC) From: P J P To: Qemu Developers Date: Wed, 15 Nov 2017 18:16:02 +0530 Message-Id: <20171115124602.12501-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 15 Nov 2017 12:46:12 +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] ps2: fix PS2Queue counter field type 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: Paolo Bonzini , Prasad J Pandit , Gerd Hoffmann , Cyrille Chatras 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 During Qemu guest migration, a destination process invokes ps2 post_load function. In that, if 'rptr' and 'count' fields were tampered, it could lead to OOB access or infinite loop issues. Change their type to 'uint8_t' so they remain within bounds. Reported-by: Cyrille Chatras Signed-off-by: Prasad J Pandit --- hw/input/ps2.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/hw/input/ps2.c b/hw/input/ps2.c index f388a23c8e..ce4b167084 100644 --- a/hw/input/ps2.c +++ b/hw/input/ps2.c @@ -90,7 +90,7 @@ typedef struct { /* Keep the data array 256 bytes long, which compatibility with older qemu versions. */ uint8_t data[256]; - int rptr, wptr, count; + uint8_t rptr, wptr, count; } PS2Queue; struct PS2State { @@ -1225,24 +1225,18 @@ static void ps2_common_reset(PS2State *s) static void ps2_common_post_load(PS2State *s) { PS2Queue *q = &s->queue; - int size; - int i; - int tmp_data[PS2_QUEUE_SIZE]; + uint8_t i, size; + uint8_t tmp_data[PS2_QUEUE_SIZE]; /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */ size = q->count > PS2_QUEUE_SIZE ? 0 : q->count; /* move the queue elements to the start of data array */ - if (size > 0) { - for (i = 0; i < size; i++) { - /* move the queue elements to the temporary buffer */ - tmp_data[i] = q->data[q->rptr]; - if (++q->rptr == 256) { - q->rptr = 0; - } - } - memcpy(q->data, tmp_data, size); + for (i = 0; i < size; i++) { + tmp_data[i] = q->data[q->rptr++]; } + memcpy(q->data, tmp_data, size); + /* reset rptr/wptr/count */ q->rptr = 0; q->wptr = size; @@ -1286,9 +1280,9 @@ static const VMStateDescription vmstate_ps2_common = { .minimum_version_id = 2, .fields = (VMStateField[]) { VMSTATE_INT32(write_cmd, PS2State), - VMSTATE_INT32(queue.rptr, PS2State), - VMSTATE_INT32(queue.wptr, PS2State), - VMSTATE_INT32(queue.count, PS2State), + VMSTATE_UINT8(queue.rptr, PS2State), + VMSTATE_UINT8(queue.wptr, PS2State), + VMSTATE_UINT8(queue.count, PS2State), VMSTATE_BUFFER(queue.data, PS2State), VMSTATE_END_OF_LIST() }