From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57674) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ceLsZ-0001l0-8m for qemu-devel@nongnu.org; Thu, 16 Feb 2017 08:13:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ceLsW-0000Xj-8q for qemu-devel@nongnu.org; Thu, 16 Feb 2017 08:13:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34176) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ceLsW-0000Wk-2X for qemu-devel@nongnu.org; Thu, 16 Feb 2017 08:13:44 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 53D38C04B321 for ; Thu, 16 Feb 2017 13:13:44 +0000 (UTC) From: Gerd Hoffmann Date: Thu, 16 Feb 2017 14:13:39 +0100 Message-Id: <1487250819-23764-4-git-send-email-kraxel@redhat.com> In-Reply-To: <1487250819-23764-1-git-send-email-kraxel@redhat.com> References: <1487250819-23764-1-git-send-email-kraxel@redhat.com> Subject: [Qemu-devel] [PATCH 3/3] usb-ccid: add check message size checks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Gerd Hoffmann Check message size too when figuring whenever we should expect more data. Fix debug message to show useful data, p->iov.size is fixed anyway if we land there, print how much we got meanwhile instead. Also check announced message size against actual message size. That is a more general fix for CVE-2017-5898 than commit "c7dfbf3 usb: ccid: check ccid apdu length". Signed-off-by: Gerd Hoffmann --- hw/usb/dev-smartcard-reader.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/hw/usb/dev-smartcard-reader.c b/hw/usb/dev-smartcard-reader.c index 1acc1fb..7cd4ed0 100644 --- a/hw/usb/dev-smartcard-reader.c +++ b/hw/usb/dev-smartcard-reader.c @@ -1011,12 +1011,19 @@ static void ccid_handle_bulk_out(USBCCIDState *s, USBPacket *p) } ccid_header = (CCID_Header *)s->bulk_out_data; - if (p->iov.size == CCID_MAX_PACKET_SIZE) { + if ((s->bulk_out_pos - 10 < ccid_header->dwLength) && + (p->iov.size == CCID_MAX_PACKET_SIZE)) { DPRINTF(s, D_VERBOSE, - "usb-ccid: bulk_in: expecting more packets (%zd/%d)\n", - p->iov.size, ccid_header->dwLength); + "usb-ccid: bulk_in: expecting more packets (%d/%d)\n", + s->bulk_out_pos - 10, ccid_header->dwLength); return; } + if (s->bulk_out_pos - 10 != ccid_header->dwLength) { + DPRINTF(s, 1, + "usb-ccid: bulk_in: message size mismatch (got %d, expected %d)\n", + s->bulk_out_pos - 10, ccid_header->dwLength); + goto err; + } DPRINTF(s, D_MORE_INFO, "%s %x %s\n", __func__, ccid_header->bMessageType, -- 1.8.3.1