From afa90858991e87762da12c5ba8adcf00ee1bd731 Mon Sep 17 00:00:00 2001
From: Mark Adler <fork@madler.net>
Date: Sat, 30 Jul 2022 15:51:11 -0700
Subject: [PATCH] [Backport]Fix a bug when getting a gzip header extra field
CVE:CVE-2022-37434
Reference:https://github.com/madler/zlib/commit/eff308af425b67093bab25f80f1ae950166bece1
---
 inflate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/inflate.c b/inflate.c
index ffb1b69..c1a1dcc 100644
--- a/inflate.c
+++ b/inflate.c
@@ -777,8 +777,9 @@ 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);
-- 
2.1.4

