package/libzlib: backport security fix for CVE-2022-37434

See: https://security-tracker.debian.org/tracker/CVE-2022-37434

Signed-off-by: Marcus Hoffmann <marcus.hoffmann@othermo.de>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

package/libzlib/0002-fix-CVE-2022-37434.patch

@@ -0,0 +1,35 @@
+From eff308af425b67093bab25f80f1ae950166bece1 Mon Sep 17 00:00:00 2001
+From: Mark Adler <fork@madler.net>
+Date: Sat, 30 Jul 2022 15:51:11 -0700
+Subject: [PATCH] Fix a bug when getting a gzip header extra field with
+ inflate().
+
+If the extra field was larger than the space the user provided with
+inflateGetHeader(), and if multiple calls of inflate() delivered
+the extra header data, then there could be a buffer overflow of the
+provided space. This commit assures that provided space is not
+exceeded.
+
+Backported from: eff308af425b67093bab25f80f1ae950166bece1
+Signed-off-by: Marcus Hoffmann <marcus.hoffmann@othermo.de>
+---
+ inflate.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/inflate.c b/inflate.c
+index 7be8c6366..7a7289749 100644
+--- a/inflate.c
++++ b/inflate.c
+@@ -763,9 +763,10 @@ int flush;
+                 copy = state->length;
+                 if (copy > have) copy = have;
+                 if (copy) {
++                    len = state->head->extra_len - state->length;
+                     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_max) {
+                         zmemcpy(state->head->extra + len, next,
+                                 len + copy > state->head->extra_max ?
+                                 state->head->extra_max - len : copy);

package/libzlib/0003-fix-CVE-2022-37434-regression.patch

@@ -0,0 +1,32 @@
+From 1eb7682f845ac9e9bf9ae35bbfb3bad5dacbd91d Mon Sep 17 00:00:00 2001
+From: Mark Adler <fork@madler.net>
+Date: Mon, 8 Aug 2022 10:50:09 -0700
+Subject: [PATCH] Fix extra field processing bug that dereferences NULL
+ state->head.
+
+The recent commit to fix a gzip header extra field processing bug
+introduced the new bug fixed here.
+
+Backported from: 1eb7682f845ac9e9bf9ae35bbfb3bad5dacbd91d
+Signed-off-by: Marcus Hoffmann <marcus.hoffmann@othermo.de>
+---
+ inflate.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/inflate.c b/inflate.c
+index 7a7289749..2a3c4fe98 100644
+--- a/inflate.c
++++ b/inflate.c
+@@ -763,10 +763,10 @@ int flush;
+                 copy = state->length;
+                 if (copy > have) copy = have;
+                 if (copy) {
+-                    len = state->head->extra_len - state->length;
+                     if (state->head != Z_NULL &&
+                         state->head->extra != Z_NULL &&
+-                        len < state->head->extra_max) {
++                        (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);

package/libzlib/libzlib.mk

@@ -14,6 +14,9 @@ LIBZLIB_PROVIDES = zlib
 LIBZLIB_CPE_ID_VENDOR = zlib
 LIBZLIB_CPE_ID_PRODUCT = zlib
 
+# 0002-fix-CVE-2022-37434.patch
+LIBZLIB_IGNORE_CVES = CVE-2022-37434
+
 # It is not possible to build only a shared version of zlib, so we build both
 # shared and static, unless we only want the static libs, and we eventually
 # selectively remove what we do not want