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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 33835C388F7 for ; Tue, 3 Nov 2020 21:08:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E05E02236F for ; Tue, 3 Nov 2020 21:08:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437717; bh=tycZLcffDK5JXjfxnA7nYvgP1KvzSEqaVcgjCbiEIgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pP/WBOv23cR+Py11PTexfMVzCi5iWICUu6EUTlNkXRPSKKXpGqbeqw5UsoWixJog0 /JxC2N5WsePJOvjUGbySgo0Yn03xNxJkCNr0E9jSWea3bw0NWCxXTHMW53CEDOh46z 0baqJcRh5CMOXs15ZTWc1BpYzplfAA1iJcnGhwcw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388514AbgKCVIg (ORCPT ); Tue, 3 Nov 2020 16:08:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:48004 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388118AbgKCVIg (ORCPT ); Tue, 3 Nov 2020 16:08:36 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2728C206B5; Tue, 3 Nov 2020 21:08:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604437715; bh=tycZLcffDK5JXjfxnA7nYvgP1KvzSEqaVcgjCbiEIgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wGq2a6da2enaqTR1UxmNH2oM5HZCNbeU2MDgbSmT1iw9R9dZ6P3LdiPejKViJVJBh 859Kgl35kpYDz46UNjIBRLlqOVLnVfvKEWGXgqJIKvn6TXuxvUoqb2hanXiptgnhFH c98jiYxeTfVjQU5fjPCE3FVBwRsBSmHuZspAbDpI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefano Garzarella , "Michael S. Tsirkin" Subject: [PATCH 4.19 172/191] vringh: fix __vringh_iov() when riov and wiov are different Date: Tue, 3 Nov 2020 21:37:44 +0100 Message-Id: <20201103203248.670682241@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203232.656475008@linuxfoundation.org> References: <20201103203232.656475008@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stefano Garzarella commit 5745bcfbbf89b158416075374254d3c013488f21 upstream. If riov and wiov are both defined and they point to different objects, only riov is initialized. If the wiov is not initialized by the caller, the function fails returning -EINVAL and printing "Readable desc 0x... after writable" error message. This issue happens when descriptors have both readable and writable buffers (eg. virtio-blk devices has virtio_blk_outhdr in the readable buffer and status as last byte of writable buffer) and we call __vringh_iov() to get both type of buffers in two different iovecs. Let's replace the 'else if' clause with 'if' to initialize both riov and wiov if they are not NULL. As checkpatch pointed out, we also avoid crashing the kernel when riov and wiov are both NULL, replacing BUG() with WARN_ON() and returning -EINVAL. Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20201008204256.162292-1-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/vringh.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -273,13 +273,14 @@ __vringh_iov(struct vringh *vrh, u16 i, desc_max = vrh->vring.num; up_next = -1; + /* You must want something! */ + if (WARN_ON(!riov && !wiov)) + return -EINVAL; + if (riov) riov->i = riov->used = 0; - else if (wiov) + if (wiov) wiov->i = wiov->used = 0; - else - /* You must want something! */ - BUG(); for (;;) { void *addr;