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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 03E42C54FD0 for ; Fri, 24 Apr 2020 12:30:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8F572084D for ; Fri, 24 Apr 2020 12:30:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587731420; bh=IUCErDYU5+chUFB9+LblbUcLmt79a5CAIndVF79zzyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=J6UYdaWRPmtD69wbf9QFGWjoTjUQ9NjifmdzUNlGimoMKvnHsIu0I062RbiB15hMa I0LqrOSCxuFO+v8A2JUsf8o5B77qN4qtcpHSncHULAkpWnInZxg+pQZItTDVTb9AIW 1byhjIJ64105ZSpBCwFDfGHfZf8s6C9fpRta8THk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbgDXMaU (ORCPT ); Fri, 24 Apr 2020 08:30:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:53758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728098AbgDXMXn (ORCPT ); Fri, 24 Apr 2020 08:23:43 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D339020776; Fri, 24 Apr 2020 12:23:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587731022; bh=IUCErDYU5+chUFB9+LblbUcLmt79a5CAIndVF79zzyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zwo1FmAO7tVEIUmg3qmd96ARoD0Msmy6lRm4rM9OPb7JgAk0z3M4rdOXADz1TbzIa 6GB5or2oSMJ7csl1mVMPd+4Hnav27fAEJZy2m0rE7RxKzeB7jSlJi9Gu2msVv2nqZo s2dDg6egHqfPY0y8HwWKqExekawle2RDvnUEI8Ss= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Juergen Gross , Wei Liu , Sasha Levin , xen-devel@lists.xenproject.org Subject: [PATCH AUTOSEL 5.4 16/26] xen/xenbus: ensure xenbus_map_ring_valloc() returns proper grant status Date: Fri, 24 Apr 2020 08:23:13 -0400 Message-Id: <20200424122323.10194-16-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200424122323.10194-1-sashal@kernel.org> References: <20200424122323.10194-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Juergen Gross [ Upstream commit 6b51fd3f65a22e3d1471b18a1d56247e246edd46 ] xenbus_map_ring_valloc() maps a ring page and returns the status of the used grant (0 meaning success). There are Xen hypervisors which might return the value 1 for the status of a failed grant mapping due to a bug. Some callers of xenbus_map_ring_valloc() test for errors by testing the returned status to be less than zero, resulting in no error detected and crashing later due to a not available ring page. Set the return value of xenbus_map_ring_valloc() to GNTST_general_error in case the grant status reported by Xen is greater than zero. This is part of XSA-316. Signed-off-by: Juergen Gross Reviewed-by: Wei Liu Link: https://lore.kernel.org/r/20200326080358.1018-1-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin --- drivers/xen/xenbus/xenbus_client.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index e17ca81561713..a38292ef79f6d 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -448,7 +448,14 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn); int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, unsigned int nr_grefs, void **vaddr) { - return ring_ops->map(dev, gnt_refs, nr_grefs, vaddr); + int err; + + err = ring_ops->map(dev, gnt_refs, nr_grefs, vaddr); + /* Some hypervisors are buggy and can return 1. */ + if (err > 0) + err = GNTST_general_error; + + return err; } EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc); -- 2.20.1