commit 8b54d6d73312186b4736cdf69a4e2e46ba15784c
author Jesus Cea <jcea@jcea.es> Mon Sep 10 00:22:39 2012 +0200
committer Jesus Cea <jcea@jcea.es> Mon Sep 10 00:22:39 2012 +0200
tree 82b6af0a0544635996bf5c899c6d58036816b1a8
parent 10fc104fede2449468fb9488bb44a9663382b3a8

Closes #15676: mmap: add empty file check prior to offset check

Modules/mmapmodule.c

diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index a5027f5..8cf0e87 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -1189,6 +1189,11 @@
     if (fd != -1 && fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) {
         if (map_size == 0) {
             off_t calc_size;
+            if (st.st_size == 0) {
+                PyErr_SetString(PyExc_ValueError,
+                                "cannot mmap an empty file");
+                return NULL;
+            }
             if (offset >= st.st_size) {
                 PyErr_SetString(PyExc_ValueError,
                                 "mmap offset is greater than file size");