Index: libexec/rtld-elf/map_object.c
===================================================================
--- libexec/rtld-elf/map_object.c
+++ libexec/rtld-elf/map_object.c
@@ -327,6 +327,18 @@
 get_elf_header(int fd, const char *path)
 {
 	Elf_Ehdr *hdr;
+	struct stat sb;
+
+	/* Make sure file has enough data for the ELF header */
+	if (fstat(fd, &sb) == -1) {
+		_rtld_error("%s: get stat error: %s", path,
+		    rtld_strerror(errno));
+		return (NULL);
+	}
+	if (sb.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);