From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: [PATCH] vfio/pci: Allow VPD short read Date: Tue, 31 May 2016 21:28:57 -0600 Message-ID: <20160601032829.31584.96315.stgit@gimli.home> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: alex.williamson@redhat.com, linux-kernel@vger.kernel.org To: kvm@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.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); }