From patchwork Mon Feb 22 12:36:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 386693 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 AB222C433DB for ; Mon, 22 Feb 2021 12:45:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A1F961606 for ; Mon, 22 Feb 2021 12:45:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231405AbhBVMpS (ORCPT ); Mon, 22 Feb 2021 07:45:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:53776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231448AbhBVMmv (ORCPT ); Mon, 22 Feb 2021 07:42:51 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4CA5564F3A; Mon, 22 Feb 2021 12:40:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613997604; bh=a8ainKRhLo+3BhY0XHJ8m4yKk7gb4ywNlu2ioz15J6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HKq0eJyEvSWDI1rqgms48tu0we6IqKCaLbkzhwik9GRGARaK8qiGe7cPV81Mtqv5M Dp1TOMGoa0e5oIHVxmetyReYx64GwKe/40JzN4RaM2WgSjGsOM69G2ony3gvaGEdbq +kgM15qEYEFIbVqf4Ow8Tm/CtHvUXTurQlmJWsX0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , Juergen Gross Subject: [PATCH 4.4 28/35] Xen/gntdev: correct error checking in gntdev_map_grant_pages() Date: Mon, 22 Feb 2021 13:36:24 +0100 Message-Id: <20210222121021.928348335@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210222121013.581198717@linuxfoundation.org> References: <20210222121013.581198717@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jan Beulich commit ebee0eab08594b2bd5db716288a4f1ae5936e9bc upstream. Failure of the kernel part of the mapping operation should also be indicated as an error to the caller, or else it may assume the respective kernel VA is okay to access. Furthermore gnttab_map_refs() failing still requires recording successfully mapped handles, so they can be unmapped subsequently. This in turn requires there to be a way to tell full hypercall failure from partial success - preset map_op status fields such that they won't "happen" to look as if the operation succeeded. Also again use GNTST_okay instead of implying its value (zero). This is part of XSA-361. Signed-off-by: Jan Beulich Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/xen/gntdev.c | 17 +++++++++-------- include/xen/grant_table.h | 1 + 2 files changed, 10 insertions(+), 8 deletions(-) --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -318,21 +318,22 @@ static int map_grant_pages(struct grant_ pr_debug("map %d+%d\n", map->index, map->count); err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL, map->pages, map->count); - if (err) - return err; for (i = 0; i < map->count; i++) { - if (map->map_ops[i].status) { + if (map->map_ops[i].status == GNTST_okay) + map->unmap_ops[i].handle = map->map_ops[i].handle; + else if (!err) err = -EINVAL; - continue; - } if (map->flags & GNTMAP_device_map) map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr; - map->unmap_ops[i].handle = map->map_ops[i].handle; - if (use_ptemod) - map->kunmap_ops[i].handle = map->kmap_ops[i].handle; + if (use_ptemod) { + if (map->kmap_ops[i].status == GNTST_okay) + map->kunmap_ops[i].handle = map->kmap_ops[i].handle; + else if (!err) + err = -EINVAL; + } } return err; } --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -157,6 +157,7 @@ gnttab_set_map_op(struct gnttab_map_gran map->flags = flags; map->ref = ref; map->dom = domid; + map->status = 1; /* arbitrary positive value */ } static inline void