From aec088c8af0ea5e3bf2a9921ff0c7a34b6036e6e Mon Sep 17 00:00:00 2001
From: Kevin Newton <kddnewton@gmail.com>
Date: Thu, 18 Jul 2024 15:46:18 -0400
Subject: [PATCH] Do not read directory

---
 include/prism/util/pm_string.h | 1 +
 src/util/pm_string.c           | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/include/prism/util/pm_string.h b/include/prism/util/pm_string.h
index d23792c0bad..e4a20558d36 100644
--- a/include/prism/util/pm_string.h
+++ b/include/prism/util/pm_string.h
@@ -9,6 +9,7 @@
 #include "prism/defines.h"
 
 #include <assert.h>
+#include <errno.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdlib.h>
diff --git a/src/util/pm_string.c b/src/util/pm_string.c
index dfc121b6a27..e9e597113f6 100644
--- a/src/util/pm_string.c
+++ b/src/util/pm_string.c
@@ -116,6 +116,13 @@ pm_string_mapped_init(pm_string_t *string, const char *filepath) {
         return false;
     }
 
+    // Ensure it is a file and not a directory
+    if (S_ISDIR(sb.st_mode)) {
+        errno = EISDIR;
+        close(fd);
+        return false;
+    }
+
     // mmap the file descriptor to virtually get the contents
     size_t size = (size_t) sb.st_size;
     uint8_t *source = NULL;