On 7/15/21 11:59 PM, Bjorn Helgaas wrote:
From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
VPD consists of a series of Small and Large Resources. Computing the size
of VPD requires only the length of each, which is specified in the generic
tag of each resource. We only expect to see ID_STRING, RO_DATA, and
RW_DATA in VPD, but it's not a problem if it contains other resource types.
Drop the validity checking of Large Resource items.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/vpd.c | 37 ++++++++++++++-----------------------
1 file changed, 14 insertions(+), 23 deletions(-)
diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
index 9c2744d79b53..d7a4a9f05bd6 100644
--- a/drivers/pci/vpd.c
+++ b/drivers/pci/vpd.c
@@ -82,31 +82,22 @@ static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
if (header[0] & PCI_VPD_LRDT) {
/* Large Resource Data Type Tag */
tag = pci_vpd_lrdt_tag(header);
- /* Only read length from known tag items */
- if ((tag == PCI_VPD_LTIN_ID_STRING) ||
- (tag == PCI_VPD_LTIN_RO_DATA) ||
- (tag == PCI_VPD_LTIN_RW_DATA)) {
- if (pci_read_vpd(dev, off+1, 2,
- &header[1]) != 2) {
- pci_warn(dev, "failed VPD read at offset %zu",
- off + 1);
- return 0;
- }
- size = pci_vpd_lrdt_size(header);
-
- /*
- * Missing EEPROM may read as 0xff.
- * Length of 0xffff (65535) cannot be valid
- * because VPD can't be that large.
- */
- if (size > PCI_VPD_MAX_SIZE)
- goto error;
- off += PCI_VPD_LRDT_TAG_SIZE + size;
- } else {
- pci_warn(dev, "invalid large VPD tag %02x at offset %zu",
- tag, off);
+ if (pci_read_vpd(dev, off + 1, 2, &header[1]) != 2) {
+ pci_warn(dev, "failed VPD read at offset %zu",
+ off + 1);
return 0;
}
+ size = pci_vpd_lrdt_size(header);
+
+ /*
+ * Missing EEPROM may read as 0xff. Length of
+ * 0xffff (65535) cannot be valid because VPD can't
+ * be that large.
+ */
+ if (size > PCI_VPD_MAX_SIZE)
+ goto error;
+
+ off += PCI_VPD_LRDT_TAG_SIZE + size;
} else {
/* Short Resource Data Type Tag */
tag = pci_vpd_srdt_tag(header);
I'm not entirely happy with this; we really have to rely on well-formed
VPD tags for the protocol to work correctly, and that's why I took the
cautious approach. But with the check for missing EEPROM I hope we've
covered the most common causes for invalid tags. Let's see how it goes.
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
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