From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 30 Nov 2012 03:17:21 +0000 (-0500)
Subject: lookup_one_len: don't accept . and ..
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=21d8a15a;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

lookup_one_len: don't accept . and ..

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

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')