From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.citrix.com ([66.165.176.89]:48242 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751922AbcFURPO (ORCPT ); Tue, 21 Jun 2016 13:15:14 -0400 Subject: Re: [Xen-devel] [PATCH] xen/pciback: Fix conf_space read/write overlap check. To: Andrey Grodzovsky , References: <1466519876-7205-1-git-send-email-andrey2805@gmail.com> CC: Boris Ostrovsky , , Jan Beulich , From: David Vrabel Message-ID: <57697614.5020003@citrix.com> Date: Tue, 21 Jun 2016 18:15:00 +0100 MIME-Version: 1.0 In-Reply-To: <1466519876-7205-1-git-send-email-andrey2805@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 21/06/16 15:37, Andrey Grodzovsky wrote: > 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. Reviewed-by: David Vrabel But the commit message could do with a concrete example of an access that failed. David > > Related to https://www.mail-archive.com/xen-devel@lists.xen.org/msg72174.html > > Cc: Jan Beulich > Cc: Boris Ostrovsky > Cc: stable@vger.kernel.org > Signed-off-by: Andrey Grodzovsky > --- > drivers/xen/xen-pciback/conf_space.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c > index 8e67336..6a25533 100644 > --- 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 *dev, int offset, int size, > 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_dev *dev, int offset, int size, u32 value) > 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, >