From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757206AbcFAD3A (ORCPT ); Tue, 31 May 2016 23:29:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52068 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755911AbcFAD26 (ORCPT ); Tue, 31 May 2016 23:28:58 -0400 Subject: [PATCH] vfio/pci: Allow VPD short read From: Alex Williamson To: kvm@vger.kernel.org Cc: alex.williamson@redhat.com, linux-kernel@vger.kernel.org Date: Tue, 31 May 2016 21:28:57 -0600 Message-ID: <20160601032829.31584.96315.stgit@gimli.home> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 01 Jun 2016 03:28:58 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The size of the VPD area is not necessarily 4-byte aligned, so a pci_vpd_read() might return less than 4 bytes. Zero our buffer and accept anything other than an error. Intel X710 NICs exercise this. Fixes: 4e1a635552d3 ("vfio/pci: Use kernel VPD access functions") Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci_config.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index 9360140..688691d 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -749,7 +749,8 @@ static int vfio_vpd_config_write(struct vfio_pci_device *vdev, int pos, if (pci_write_vpd(pdev, addr & ~PCI_VPD_ADDR_F, 4, &data) != 4) return count; } else { - if (pci_read_vpd(pdev, addr, 4, &data) != 4) + data = 0; + if (pci_read_vpd(pdev, addr, 4, &data) < 0) return count; *pdata = cpu_to_le32(data); }