1 files changed, 42 insertions, 23 deletions

diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index c4bcdbaf4d4..7f19f23d38a 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1298,41 +1298,60 @@ int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
 	}
 }
 
-/* Compare given dentry name with last component in given path,
- * return of 0 indicates a match. */
-int audit_compare_dname_path(const char *dname, const char *path,
-			     int *dirlen)
+/**
+ * parent_len - find the length of the parent portion of a pathname
+ * @path: pathname of which to determine length
+ */
+int parent_len(const char *path)
 {
-	int dlen, plen;
+	int plen;
 	const char *p;
 
-	if (!dname || !path)
-		return 1;
-
-	dlen = strlen(dname);
 	plen = strlen(path);
-	if (plen < dlen)
-		return 1;
+
+	if (plen == 0)
+		return plen;
 
 	/* disregard trailing slashes */
 	p = path + plen - 1;
 	while ((*p == '/') && (p > path))
 		p--;
 
-	/* find last path component */
-	p = p - dlen + 1;
-	if (p < path)
+	/* walk backward until we find the next slash or hit beginning */
+	while ((*p != '/') && (p > path))
+		p--;
+
+	/* did we find a slash? Then increment to include it in path */
+	if (*p == '/')
+		p++;
+
+	return p - path;
+}
+
+/**
+ * audit_compare_dname_path - compare given dentry name with last component in
+ * 			      given path. Return of 0 indicates a match.
+ * @dname:	dentry name that we're comparing
+ * @path:	full pathname that we're comparing
+ * @parentlen:	length of the parent if known. Passing in AUDIT_NAME_FULL
+ * 		here indicates that we must compute this value.
+ */
+int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
+{
+	int dlen, pathlen;
+	const char *p;
+
+	dlen = strlen(dname);
+	pathlen = strlen(path);
+	if (pathlen < dlen)
 		return 1;
-	else if (p > path) {
-		if (*--p != '/')
-			return 1;
-		else
-			p++;
-	}
 
-	/* return length of path's directory component */
-	if (dirlen)
-		*dirlen = p - path;
+	parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
+	if (pathlen - parentlen != dlen)
+		return 1;
+
+	p = path + parentlen;
+
 	return strncmp(p, dname, dlen);
 }