From ce7585f3c4d76bca1dff4b66ae1ea32552954f9e Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@redhat.com>
Date: Tue, 31 May 2016 21:25:52 -0600
Subject: [PATCH] vfio/pci: Allow VPD short read
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>
---
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 93601407dab8a0..688691d9058dd9 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);
}
--
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