Issue #10916: mmap should not segfault when a file is mapped using 0 as
length and a non-zero offset, and an attempt to read past the end of file
is made (IndexError is raised instead). Patch by Ross Lagerwall.
Requested by Georg.
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 8a22752..ef026b2 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -1116,7 +1116,7 @@
# endif
if (fd != -1 && fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) {
if (map_size == 0) {
- map_size = st.st_size;
+ map_size = st.st_size - offset;
} else if ((size_t)offset + (size_t)map_size > st.st_size) {
PyErr_SetString(PyExc_ValueError,
"mmap length is greater than file size");