From patchwork Mon Feb 22 12:13:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 386192 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 71835C433E0 for ; Mon, 22 Feb 2021 12:22:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B3AB64E61 for ; Mon, 22 Feb 2021 12:22:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230202AbhBVMVl (ORCPT ); Mon, 22 Feb 2021 07:21:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:45468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231129AbhBVMRq (ORCPT ); Mon, 22 Feb 2021 07:17:46 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 17A6B64F17; Mon, 22 Feb 2021 12:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613996242; bh=U5swuH88HlSYBGibQtVeUoXo0V/IMADHqkcqixFhXfk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jli449oyY+eeMcjzVEQKNKCFJRlpFgfOqifrhiS2jVeBCDUTur7XdlSbTP4T3rDwa qfWgME1WLk3d8ZvXGw0OcbtB9v2yZHgiO1wOsrNf9lIJyjyYLlepHNZwTTwK0EnRN+ Xl5q96GrfxcfzxG2Kcn92Q8r6/I60jl1ndD3gOgI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , Juergen Gross Subject: [PATCH 4.19 45/50] xen-blkback: dont "handle" error by BUG() Date: Mon, 22 Feb 2021 13:13:36 +0100 Message-Id: <20210222121026.978630130@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210222121019.925481519@linuxfoundation.org> References: <20210222121019.925481519@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 5a264285ed1cd32e26d9de4f3c8c6855e467fd63 upstream. In particular -ENOMEM may come back here, from set_foreign_p2m_mapping(). Don't make problems worse, the more that handling elsewhere (together with map's status fields now indicating whether a mapping wasn't even attempted, and hence has to be considered failed) doesn't require this odd way of dealing with errors. This is part of XSA-362. 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/block/xen-blkback/blkback.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -867,10 +867,8 @@ again: break; } - if (segs_to_map) { + if (segs_to_map) ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map); - BUG_ON(ret); - } /* * Now swizzle the MFN in our domain with the MFN from the other domain @@ -885,7 +883,7 @@ again: pr_debug("invalid buffer -- could not remap it\n"); put_free_pages(ring, &pages[seg_idx]->page, 1); pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE; - ret |= 1; + ret |= !ret; goto next; } pages[seg_idx]->handle = map[new_map_idx].handle;