From a544db3020b3f46b4050b4cf153ed3e4edd8a30a Mon Sep 17 00:00:00 2001
From: Orgad Shaneh <orgad.shaneh@audiocodes.com>
Date: Wed, 2 Oct 2024 10:13:14 +0300
Subject: [PATCH] win32: zlib: Fix buffer overflow on inflate (CVE-2022-37434)

---
 win32port/zlib/inflate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/win32port/zlib/inflate.c b/win32port/zlib/inflate.c
index 664c4b9cc..21631c75e 100644
--- a/win32port/zlib/inflate.c
+++ b/win32port/zlib/inflate.c
@@ -720,8 +720,9 @@ int flush;
                 if (copy > have) copy = have;
                 if (copy) {
                     if (state->head != Z_NULL &&
-                        state->head->extra != Z_NULL) {
-                        len = state->head->extra_len - state->length;
+                        state->head->extra != Z_NULL &&
+                        (len = state->head->extra_len - state->length) <
+                            state->head->extra_max) {
                         zmemcpy(state->head->extra + len, next,
                                 len + copy > state->head->extra_max ?
                                 state->head->extra_max - len : copy);