Index: head/lib/libc/tests/gen/Makefile
===================================================================
--- head/lib/libc/tests/gen/Makefile
+++ head/lib/libc/tests/gen/Makefile
@@ -11,6 +11,7 @@
 ATF_TESTS_C+=		popen_test
 ATF_TESTS_C+=		posix_spawn_test
 ATF_TESTS_C+=		wordexp_test
+ATF_TESTS_C+=		dlopen_empty_test
 
 # TODO: t_closefrom, t_cpuset, t_fmtcheck, t_randomid, t_sleep
 # TODO: t_siginfo (fixes require further inspection)
Index: head/lib/libc/tests/gen/dlopen_empty_test.c
===================================================================
--- head/lib/libc/tests/gen/dlopen_empty_test.c
+++ head/lib/libc/tests/gen/dlopen_empty_test.c
@@ -0,0 +1,97 @@
+/*-
+ * Copyright (c) 2016 Maksym Sobolyev
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/stat.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <atf-c.h>
+
+static const char *funname;
+static char *soname;
+
+static void
+sigsegv_handler(int sig __unused)
+{
+        unlink(soname);
+        free(soname);
+        atf_tc_fail("got SIGSEGV in the %s(3)", funname);
+}
+
+ATF_TC(dlopen_empty_test);
+ATF_TC_HEAD(dlopen_empty_test, tc)
+{
+        atf_tc_set_md_var(tc, "descr", "Tests the dlopen() of an empty file "
+                      "returns an error");
+}
+ATF_TC_BODY(dlopen_empty_test, tc)
+{
+        char tempname[] = "/tmp/temp.XXXXXX";
+        char *fname;
+        int fd;
+        void *dlh;
+        struct sigaction act, oact;
+
+        fname = mktemp(tempname);
+        ATF_REQUIRE_MSG(fname != NULL, "mktemp failed; errno=%d", errno);
+        asprintf(&soname, "%s.so", fname);
+        ATF_REQUIRE_MSG(soname != NULL, "asprintf failed; errno=%d", ENOMEM);
+        fd = open(soname, O_WRONLY | O_CREAT | O_TRUNC, DEFFILEMODE);
+        ATF_REQUIRE_MSG(fd != -1, "open(\"%s\") failed; errno=%d", soname, errno);
+        close(fd);
+
+        act.sa_handler = sigsegv_handler;
+        act.sa_flags = 0;
+        sigemptyset(&act.sa_mask);
+        ATF_CHECK_MSG(sigaction(SIGSEGV, &act, &oact) != -1,
+            "sigaction() failed");
+
+        funname = "dlopen";
+        dlh = dlopen(soname, RTLD_LAZY);
+        if (dlh != NULL) {
+                funname = "dlclose";
+                dlclose(dlh);
+        }
+        ATF_REQUIRE_MSG(dlh == NULL, "dlopen(\"%s\") did not fail", soname);
+        unlink(soname);
+        free(soname);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+
+        ATF_TP_ADD_TC(tp, dlopen_empty_test);
+
+        return (atf_no_error());
+}
Index: head/libexec/rtld-elf/map_object.c
===================================================================
--- head/libexec/rtld-elf/map_object.c
+++ head/libexec/rtld-elf/map_object.c
@@ -38,7 +38,7 @@
 #include "debug.h"
 #include "rtld.h"
 
-static Elf_Ehdr *get_elf_header(int, const char *);
+static Elf_Ehdr *get_elf_header(int, const char *, const struct stat *);
 static int convert_prot(int);	/* Elf flags -> mmap protection */
 static int convert_flags(int); /* Elf flags -> mmap flags */
 
@@ -91,7 +91,7 @@
     char *note_map;
     size_t note_map_len;
 
-    hdr = get_elf_header(fd, path);
+    hdr = get_elf_header(fd, path, sb);
     if (hdr == NULL)
 	return (NULL);
 
@@ -324,10 +324,16 @@
 }
 
 static Elf_Ehdr *
-get_elf_header(int fd, const char *path)
+get_elf_header(int fd, const char *path, const struct stat *sbp)
 {
 	Elf_Ehdr *hdr;
 
+	/* Make sure file has enough data for the ELF header */
+	if (sbp != NULL && sbp->st_size < sizeof(Elf_Ehdr)) {
+		_rtld_error("%s: invalid file format", path);
+		return (NULL);
+	}
+
 	hdr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE | MAP_PREFAULT_READ,
 	    fd, 0);
 	if (hdr == (Elf_Ehdr *)MAP_FAILED) {