lookup_one_len: don't accept . and ..
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 30 Nov 2012 03:17:21 +0000 (22:17 -0500)
committerAl Viro <viro@zeniv.linux.org.uk>
Fri, 30 Nov 2012 03:17:21 +0000 (22:17 -0500)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/namei.c

index 937f9d50c84bdead7516057fead3d5a702ead4b9..5f4cdf3ad913fec928835d87fbe499efdf7d67e5 100644 (file)
@@ -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')