From patchwork Mon Nov 9 12:55:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 322810 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 6EA12C4741F for ; Mon, 9 Nov 2020 12:58:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14230207BC for ; Mon, 9 Nov 2020 12:58:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926701; bh=ZLeOPp5R7YSkfvBZOBDb/LOc6Tl0ZFDGmKBNdeIOBdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KN0Rh0ax4S6JZiZD4oOJ49MPwCsX6G6BYhtzMOqGvrGT76LoVswOW55Ih/F+Mx34E gnCAX1k83qhP+0FfURyOqF0gTk37rLE7y3DenU0Om9KYbmVeqV0p8kCcqwPZSb4TXE +o+h8se0ePw/PUtHrW12fWE0wXh1ZevM5eY4/u9c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730132AbgKIM6T (ORCPT ); Mon, 9 Nov 2020 07:58:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:52470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730088AbgKIM6B (ORCPT ); Mon, 9 Nov 2020 07:58:01 -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 414EE2083B; Mon, 9 Nov 2020 12:58:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926680; bh=ZLeOPp5R7YSkfvBZOBDb/LOc6Tl0ZFDGmKBNdeIOBdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DCaAJWi4Nur8vdayUXdmB0XF57gNRed8ADTvUCnu98lje5TH6J32PrUXlTsYVSurI i8ggfB1vItPQrIB4ftqEfTPlSHbkK5naENhRqE4810PU+7weJjrOk6iiJ+rC/z+T0K rLf1KqdDRBjuY/VCRexOIYas0iOq2/QA98KKTRTg= 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 4.4 54/86] vringh: fix __vringh_iov() when riov and wiov are different Date: Mon, 9 Nov 2020 13:55:01 +0100 Message-Id: <20201109125023.400876081@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201109125020.852643676@linuxfoundation.org> References: <20201109125020.852643676@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 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 @@ -272,13 +272,14 @@ __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;