Fix missing/incomplete NULL checks in multiple source files (#104564)

Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>

5 files changed, 20 insertions, 1 deletions

diff --git a/Modules/_zoneinfo.c b/Modules/_zoneinfo.c
index c8c791b..0dcdb4d 100644
--- a/Modules/_zoneinfo.c
+++ b/Modules/_zoneinfo.c
@@ -2381,7 +2381,12 @@ get_local_timestamp(PyObject *dt, int64_t *local_ts)
 /////
 // Functions for cache handling
 
-/* Constructor for StrongCacheNode */
+/* Constructor for StrongCacheNode
+ *
+ * This function doesn't set MemoryError if PyMem_Malloc fails,
+ * as the cache intentionally doesn't propagate exceptions
+ * and fails silently if error occurs.
+ */
 static StrongCacheNode *
 strong_cache_node_new(PyObject *key, PyObject *zone)
 {
@@ -2572,6 +2577,9 @@ update_strong_cache(zoneinfo_state *state, const PyTypeObject *const type,
     }
 
     StrongCacheNode *new_node = strong_cache_node_new(key, zone);
+    if (new_node == NULL) {
+        return;
+    }
     StrongCacheNode **root = &(state->ZONEINFO_STRONG_CACHE);
     move_strong_cache_node_to_front(state, root, new_node);
 
diff --git a/Modules/errnomodule.c b/Modules/errnomodule.c
index fddde96..3d0c2d7 100644
--- a/Modules/errnomodule.c
+++ b/Modules/errnomodule.c
@@ -84,6 +84,7 @@ errno_exec(PyObject *module)
     PyObject *module_dict = PyModule_GetDict(module);
     PyObject *error_dict = PyDict_New();
     if (!module_dict || !error_dict) {
+        Py_XDECREF(error_dict);
         return -1;
     }
     if (PyDict_SetItemString(module_dict, "errorcode", error_dict) < 0) {
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 531f26b..2fe9973 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -9023,6 +9023,10 @@ os_setgroups(PyObject *module, PyObject *groups)
     }
 
     gid_t *grouplist = PyMem_New(gid_t, len);
+    if (grouplist == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
     for (Py_ssize_t i = 0; i < len; i++) {
         PyObject *elem;
         elem = PySequence_GetItem(groups, i);
diff --git a/Modules/sha1module.c b/Modules/sha1module.c
index c66269b..ef8e067 100644
--- a/Modules/sha1module.c
+++ b/Modules/sha1module.c
@@ -73,6 +73,9 @@ static SHA1object *
 newSHA1object(SHA1State *st)
 {
     SHA1object *sha = (SHA1object *)PyObject_GC_New(SHA1object, st->sha1_type);
+    if (sha == NULL) {
+        return NULL;
+    }
     sha->lock = NULL;
     PyObject_GC_Track(sha);
     return sha;
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index b67844a..534d065 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -1722,6 +1722,9 @@ ZlibDecompressor__new__(PyTypeObject *cls,
         return NULL;
     }
     ZlibDecompressor *self = PyObject_New(ZlibDecompressor, cls);
+    if (self == NULL) {
+        return NULL;
+    }
     self->eof = 0;
     self->needs_input = 1;
     self->avail_in_real = 0;