From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932257AbcHHTwM (ORCPT ); Mon, 8 Aug 2016 15:52:12 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35694 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752986AbcHHTMx (ORCPT ); Mon, 8 Aug 2016 15:12:53 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrey Grodzovsky , Boris Ostrovsky , Jan Beulich , David Vrabel Subject: [PATCH 4.4 19/68] xen/pciback: Fix conf_space read/write overlap check. Date: Mon, 8 Aug 2016 21:10:54 +0200 Message-Id: <20160808180210.649147902@linuxfoundation.org> X-Mailer: git-send-email 2.9.2 In-Reply-To: <20160808180209.697765393@linuxfoundation.org> References: <20160808180209.697765393@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrey Grodzovsky commit 02ef871ecac290919ea0c783d05da7eedeffc10e upstream. Current overlap check is evaluating to false a case where a filter field is fully contained (proper subset) of a r/w request. This change applies classical overlap check instead to include all the scenarios. More specifically, for (Hilscher GmbH CIFX 50E-DP(M/S)) device driver the logic is such that the entire confspace is read and written in 4 byte chunks. In this case as an example, CACHE_LINE_SIZE, LATENCY_TIMER and PCI_BIST are arriving together in one call to xen_pcibk_config_write() with offset == 0xc and size == 4. With the exsisting overlap check the LATENCY_TIMER field (offset == 0xd, length == 1) is fully contained in the write request and hence is excluded from write, which is incorrect. Signed-off-by: Andrey Grodzovsky Reviewed-by: Boris Ostrovsky Reviewed-by: Jan Beulich Signed-off-by: David Vrabel Signed-off-by: Greg Kroah-Hartman --- drivers/xen/xen-pciback/conf_space.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/xen/xen-pciback/conf_space.c +++ b/drivers/xen/xen-pciback/conf_space.c @@ -183,8 +183,7 @@ int xen_pcibk_config_read(struct pci_dev field_start = OFFSET(cfg_entry); field_end = OFFSET(cfg_entry) + field->size; - if ((req_start >= field_start && req_start < field_end) - || (req_end > field_start && req_end <= field_end)) { + if (req_end > field_start && field_end > req_start) { err = conf_space_read(dev, cfg_entry, field_start, &tmp_val); if (err) @@ -230,8 +229,7 @@ int xen_pcibk_config_write(struct pci_de field_start = OFFSET(cfg_entry); field_end = OFFSET(cfg_entry) + field->size; - if ((req_start >= field_start && req_start < field_end) - || (req_end > field_start && req_end <= field_end)) { + if (req_end > field_start && field_end > req_start) { tmp_val = 0; err = xen_pcibk_config_read(dev, field_start,