`_freeze_module.c` has several unhandled nulls

[sobolevn]

Bug report

https://github.com/python/cpython/blob/main/Programs/_freeze_module.c has several unhandled nulls.

I have a PR ready:

diff --git Programs/_freeze_module.c Programs/_freeze_module.c
index 2a462a42cda..891e4256e89 100644
--- Programs/_freeze_module.c
+++ Programs/_freeze_module.c
@@ -110,6 +110,9 @@ static PyObject *
 compile_and_marshal(const char *name, const char *text)
 {
     char *filename = (char *) malloc(strlen(name) + 10);
+    if (filename == NULL) {
+        return PyErr_NoMemory();
+    }
     sprintf(filename, "<frozen %s>", name);
     PyObject *code = Py_CompileStringExFlags(text, filename,
                                              Py_file_input, NULL, 0);
@@ -133,6 +136,9 @@ get_varname(const char *name, const char *prefix)
 {
     size_t n = strlen(prefix);
     char *varname = (char *) malloc(strlen(name) + n + 1);
+    if (varname == NULL) {
+        return NULL;
+    }
     (void)strcpy(varname, prefix);
     for (size_t i = 0; name[i] != '\0'; i++) {
         if (name[i] == '.') {
@@ -178,6 +184,11 @@ write_frozen(const char *outpath, const char *inpath, const char *name,
 
     fprintf(outfile, "%s\n", header);
     char *arrayname = get_varname(name, "_Py_M__");
+    if (arrayname == NULL) {
+        fprintf(stderr, "memory error: could not allocate varname\n");
+        fclose(outfile);
+        return -1;
+    }
     write_code(outfile, marshalled, arrayname);
     free(arrayname);

Linked PRs

• gh-123919: Fix null handling in _freeze_module.c #123920
• [3.13] gh-123919: Fix null handling in _freeze_module.c (GH-123920) #123948
• [3.12] gh-123919: Fix null handling in _freeze_module.c (GH-123920) #123949