From 21d8a15ac333b05f1fecdf9fdc30996be2e11d60 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 29 Nov 2012 22:17:21 -0500
Subject: [PATCH] lookup_one_len: don't accept . and ..
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/namei.c b/fs/namei.c
index 937f9d50c84b..5f4cdf3ad913 100644
--- 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')
--
2.20.1