apparmor: Replace deprecated strcpy in d_namespace_path

strcpy() is deprecated; replace it with a direct '/' assignment. The
buffer is already NUL-terminated, so there is no need to copy an
additional NUL terminator as strcpy() did.

Update the comment and add the local variable 'is_root' for clarity.

Closes: KSPP/linux#88
Signed-off-by: Thorsten Blum <[email protected]>
Signed-off-by: John Johansen <[email protected]>

Author: toblux

security/apparmor/path.c

@@ -164,12 +164,15 @@ static int d_namespace_path(const struct path *path, char *buf, char **name,
 	}
 
 out:
-	/*
-	 * Append "/" to the pathname.  The root directory is a special
-	 * case; it already ends in slash.
+	/* Append "/" to directory paths, except for root "/" which
+	 * already ends in a slash.
 	 */
-	if (!error && isdir && ((*name)[1] != '\0' || (*name)[0] != '/'))
-		strcpy(&buf[aa_g_path_max - 2], "/");
+	if (!error && isdir) {
+		bool is_root = (*name)[0] == '/' && (*name)[1] == '\0';
+
+		if (!is_root)
+			buf[aa_g_path_max - 2] = '/';
+	}
 
 	return error;
 }