Merge pull request #63 from oschwald/greg/fix-off-by-one

horgh · web-flow · commit a163813d4db1 · 2019-12-11T15:15:50.000-08:00
Fix off-by-one error in pointer check
diff --git a/reader.go b/reader.go
@@ -281,7 +281,7 @@ func (r *Reader) retrieveData(pointer uint, result interface{}) error {
 func (r *Reader) resolveDataPointer(pointer uint) (uintptr, error) {
 	var resolved = uintptr(pointer - r.Metadata.NodeCount - dataSectionSeparatorSize)
 
-	if resolved > uintptr(len(r.buffer)) {
+	if resolved >= uintptr(len(r.buffer)) {
 		return 0, newInvalidDatabaseError("the MaxMind DB file's search tree is corrupt")
 	}
 	return resolved, nil

Original file line number	Diff line number	Diff line change
`@@ -281,7 +281,7 @@ func (r *Reader) retrieveData(pointer uint, result interface{}) error {`
`281`	`281`	`func (r *Reader) resolveDataPointer(pointer uint) (uintptr, error) {`
`282`	`282`	`var resolved = uintptr(pointer - r.Metadata.NodeCount - dataSectionSeparatorSize)`
`283`	`283`
`284`		`- if resolved > uintptr(len(r.buffer)) {`
	`284`	`+ if resolved >= uintptr(len(r.buffer)) {`
`285`	`285`	`return 0, newInvalidDatabaseError("the MaxMind DB file's search tree is corrupt")`
`286`	`286`	`}`
`287`	`287`	`return resolved, nil`