1 files changed, 85 insertions, 2 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index a7f00699d0cbd..4850f06122680 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -285,8 +285,63 @@ struct pci_vpd_pci22 {
 	u16	flag;
 	u8	cap;
 	u8	busy:1;
+	u8	valid:1;
 };
 
+/**
+ * pci_vpd_size - determine actual size of Vital Product Data
+ * @dev:	pci device struct
+ * @old_size:	current assumed size, also maximum allowed size
+ */
+static size_t pci_vpd_pci22_size(struct pci_dev *dev, size_t old_size)
+{
+	size_t off = 0;
+	unsigned char header[1+2];	/* 1 byte tag, 2 bytes length */
+
+	while (off < old_size &&
+	       pci_read_vpd(dev, off, 1, header) == 1) {
+		unsigned char tag;
+
+		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) {
+					dev_warn(&dev->dev,
+						 "invalid large VPD tag %02x size at offset %zu",
+						 tag, off + 1);
+					return 0;
+				}
+				off += PCI_VPD_LRDT_TAG_SIZE +
+					pci_vpd_lrdt_size(header);
+			}
+		} else {
+			/* Short Resource Data Type Tag */
+			off += PCI_VPD_SRDT_TAG_SIZE +
+				pci_vpd_srdt_size(header);
+			tag = pci_vpd_srdt_tag(header);
+		}
+
+		if (tag == PCI_VPD_STIN_END)	/* End tag descriptor */
+			return off;
+
+		if ((tag != PCI_VPD_LTIN_ID_STRING) &&
+		    (tag != PCI_VPD_LTIN_RO_DATA) &&
+		    (tag != PCI_VPD_LTIN_RW_DATA)) {
+			dev_warn(&dev->dev,
+				 "invalid %s VPD tag %02x at offset %zu",
+				 (header[0] & PCI_VPD_LRDT) ? "large" : "short",
+				 tag, off);
+			return 0;
+		}
+	}
+	return 0;
+}
+
 /*
  * Wait for last operation to complete.
  * This code has to spin since there is no other notification from the PCI
@@ -337,9 +392,25 @@ static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
 	loff_t end = pos + count;
 	u8 *buf = arg;
 
-	if (pos < 0 || pos > vpd->base.len || end > vpd->base.len)
+	if (pos < 0)
 		return -EINVAL;
 
+	if (!vpd->valid) {
+		vpd->valid = 1;
+		vpd->base.len = pci_vpd_pci22_size(dev, vpd->base.len);
+	}
+
+	if (vpd->base.len == 0)
+		return -EIO;
+
+	if (pos >= vpd->base.len)
+		return 0;
+
+	if (end > vpd->base.len) {
+		end = vpd->base.len;
+		count = end - pos;
+	}
+
 	if (mutex_lock_killable(&vpd->lock))
 		return -EINTR;
 
@@ -389,7 +460,18 @@ static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count
 	loff_t end = pos + count;
 	int ret = 0;
 
-	if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len)
+	if (pos < 0 || (pos & 3) || (count & 3))
+		return -EINVAL;
+
+	if (!vpd->valid) {
+		vpd->valid = 1;
+		vpd->base.len = pci_vpd_pci22_size(dev, vpd->base.len);
+	}
+
+	if (vpd->base.len == 0)
+		return -EIO;
+
+	if (end > vpd->base.len)
 		return -EINVAL;
 
 	if (mutex_lock_killable(&vpd->lock))
@@ -496,6 +578,7 @@ int pci_vpd_pci22_init(struct pci_dev *dev)
 	mutex_init(&vpd->lock);
 	vpd->cap = cap;
 	vpd->busy = 0;
+	vpd->valid = 0;
 	dev->vpd = &vpd->base;
 	return 0;
 }