@@ -, +, @@ 
---
 libsandbox/wrapper-funcs/opendir.c           |  2 ++
 libsandbox/wrapper-funcs/opendir_pre_check.c | 26 ++++++++++++++++++++++++++
 libsandbox/wrappers.h                        |  1 +
 3 files changed, 29 insertions(+)
 create mode 100644 libsandbox/wrapper-funcs/opendir_pre_check.c
--- a/libsandbox/wrapper-funcs/opendir.c	
+++ a/libsandbox/wrapper-funcs/opendir.c	
@@ -10,4 +10,6 @@ 
 #define WRAPPER_SAFE() SB_SAFE(name)
 #define WRAPPER_RET_TYPE DIR *
 #define WRAPPER_RET_DEFAULT NULL
+#define WRAPPER_PRE_CHECKS() sb_opendir_pre_check(STRING_NAME, name)
+
 #include "__wrapper_simple.c"
--- a/libsandbox/wrapper-funcs/opendir_pre_check.c	
+++ a/libsandbox/wrapper-funcs/opendir_pre_check.c	
@@ -0,0 +1,26 @@ 
+/*
+ * opendir() pre-check.
+ *
+ * Copyright 1999-2016 Gentoo Foundation
+ * Licensed under the GPL-2
+ */
+
+bool sb_opendir_pre_check(const char *func, const char *name)
+{
+	/* If length of name is larger than PATH_MAX, we would mess it up
+	 * before it reaches the open syscall, which would cleanly error out
+	 * via sandbox as well (actually with much smaller lengths than even
+	 * PATH_MAX).
+	 * So error out early in this case, in order to avoid an abort in
+	 * check_syscall later on, which gets ran for opendir, despite it not
+	 * being a syscall.
+	 */
+	if (strlen(name) > PATH_MAX) {
+		errno = ENAMETOOLONG;
+		sb_debug_dyn("EARLY FAIL: %s(%s): %s\n",
+			func, name, strerror(errno));
+		return false;
+	}
+
+	return true;
+}
--- a/libsandbox/wrappers.h	
+++ a/libsandbox/wrappers.h	
@@ -27,6 +27,7 @@ attribute_hidden bool sb_fopen64_pre_check  (const char *func, const char *pathn
 attribute_hidden bool sb_mkdirat_pre_check  (const char *func, const char *pathname, int dirfd);
 attribute_hidden bool sb_openat_pre_check   (const char *func, const char *pathname, int dirfd, int flags);
 attribute_hidden bool sb_openat64_pre_check (const char *func, const char *pathname, int dirfd, int flags);
+attribute_hidden bool sb_opendir_pre_check  (const char *func, const char *name);
 attribute_hidden bool sb_unlinkat_pre_check (const char *func, const char *pathname, int dirfd);
 attribute_hidden bool sb_common_at_pre_check(const char *func, const char **pathname, int dirfd,
                                              char *dirfd_path, size_t dirfd_path_len);
--