lookup_one_len: don't accept . and ..

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
mariux64 · Nov 30, 2012 · 21d8a15 · 21d8a15
1 parent 0903a0c
commit 21d8a15
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/fs/namei.c b/fs/namei.c
@@ -2131,6 +2131,11 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 	if (!len)
 		return ERR_PTR(-EACCES);
 
+	if (unlikely(name[0] == '.')) {
+		if (len < 2 || (len == 2 && name[1] == '.'))
+			return ERR_PTR(-EACCES);
+	}
+
 	while (len--) {
 		c = *(const unsigned char *)name++;
 		if (c == '/' || c == '\0')