| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 063/312] vfio/pci: Allow VPD short read | Date | Fri, 8 May 2020 14:30:54 +0200 |
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From: Alex Williamson <alex.williamson@redhat.com>
commit ce7585f3c4d76bca1dff4b66ae1ea32552954f9e upstream.
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 <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/vfio/pci/vfio_pci_config.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -698,7 +698,8 @@ static int vfio_vpd_config_write(struct 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); }
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