From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A4C1C4360C for ; Sun, 13 Oct 2019 11:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 437EA207FF for ; Sun, 13 Oct 2019 11:42:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729408AbfJMLm3 (ORCPT ); Sun, 13 Oct 2019 07:42:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52044 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729376AbfJMLm2 (ORCPT ); Sun, 13 Oct 2019 07:42:28 -0400 Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DF13885546 for ; Sun, 13 Oct 2019 11:42:27 +0000 (UTC) Received: by mail-qt1-f200.google.com with SMTP id j5so14850279qtn.10 for ; Sun, 13 Oct 2019 04:42:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=LyPdJiu+Pv3Ms2s+9K7y5cFNFk6/oEkuyO+dRyVq8dg=; b=RLPtuZTP3SeCl2VVZGZ6YtUzNB7kyWESxYeJh2biClRMLZkgyE+ayztrtlk3IJvzc6 4puqF76gdzL/IXs3CDM2sJWr9j36Fz3UBE2vs/IvojkcKKzQ17G2+a44R1dCM8i+VzIQ 1RJCwuC6ZaqfPYkbRmCZR+6vnTEGBhvobiLODWhtFN4Bgljh+zwVM77RSg6ihBxSC2w+ 375Z2OtB0X3J6Jkf9K6SyC7VhvekdmytRaEjNBGULxnDRdiSh3MUUtI8WMq4N1DASvTb fMjB6paV37IQJXvQEp00NP082Tm8G0bmrCm/46PdWmUJ5MT3XHNCMlfNs3nLELVnPlTI iFkw== X-Gm-Message-State: APjAAAXBqu6EJDlYge+b37fN2wEDfxJOd3HIm4GX8kQUS8X5Tg9sF85h cZ8pJdbsnxNX3tbpJ/X1+zSVB3W3ZUY6mN9t2EzH9N0bxdUDbl0OFYJBhMGgQdtzg87yLuBTQ+B UyZx0AZn+or0RFZk67QYBAS+d X-Received: by 2002:a0c:c792:: with SMTP id k18mr25297615qvj.154.1570966946779; Sun, 13 Oct 2019 04:42:26 -0700 (PDT) X-Google-Smtp-Source: APXvYqyhx3XLFozvF0Fexkmjc2uJBOUXPVXIPjvAKX3RiiVhxNpPC56P8T4wN2MQG4g59b9OLo3Gdg== X-Received: by 2002:a0c:c792:: with SMTP id k18mr25297597qvj.154.1570966946584; Sun, 13 Oct 2019 04:42:26 -0700 (PDT) Received: from redhat.com (bzq-79-176-10-77.red.bezeqint.net. [79.176.10.77]) by smtp.gmail.com with ESMTPSA id z5sm7213125qtb.49.2019.10.13.04.42.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 13 Oct 2019 04:42:25 -0700 (PDT) Date: Sun, 13 Oct 2019 07:42:22 -0400 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, Jason Wang Subject: [PATCH RFC v4 5/5] vhost: last descriptor must have NEXT clear Message-ID: <20191013113940.2863-6-mst@redhat.com> References: <20191013113940.2863-1-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191013113940.2863-1-mst@redhat.com> X-Mailer: git-send-email 2.22.0.678.g13338e74b8 X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org fetch_buf already guarantees we exit on a descriptor without a NEXT flag. Add a BUG_ON statement to make sure we don't overflow the buffer in case of a bug. Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index d46c28149f6f..09f594bb069a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2656,6 +2656,8 @@ int vhost_get_vq_desc_batch(struct vhost_virtqueue *vq, break; } + BUG_ON(i >= vq->ndescs); + vq->first_desc = i + 1; return ret; -- MST