[PATCH] zlib: Incorporate fix for CVE-2022-37434

["Peter Müller" <peter.mueller@ipfire.org>]

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https://www.cve.org/CVERecord?id=CVE-2022-37434

Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
---
 lfs/zlib                              |  4 ++++
 src/patches/zlib-CVE-2022-37434.patch | 29 +++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 src/patches/zlib-CVE-2022-37434.patch

diff --git a/lfs/zlib b/lfs/zlib
index 19740fb7f..8197c9b45 100644
--- a/lfs/zlib
+++ b/lfs/zlib
@@ -77,6 +77,10 @@ $(subst %,%_BLAKE2,$(objects)) :
 $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
 	@$(PREBUILD)
 	@rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar axf $(DIR_DL)/$(DL_FILE)
+
+	# Fix for CVE-2022-37434
+	cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/zlib-CVE-2022-37434.patch
+
 	cd $(DIR_APP) && CROSS_PREFIX=$(CROSS_PREFIX) ./configure --prefix=$(PREFIX) --shared
 	cd $(DIR_APP) && make $(MAKETUNING)
 	cd $(DIR_APP) && make install
diff --git a/src/patches/zlib-CVE-2022-37434.patch b/src/patches/zlib-CVE-2022-37434.patch
new file mode 100644
index 000000000..95e9f173f
--- /dev/null
+++ b/src/patches/zlib-CVE-2022-37434.patch
@@ -0,0 +1,29 @@
+commit eff308af425b67093bab25f80f1ae950166bece1
+Author: Mark Adler <fork(a)madler.net>
+Date:   Sat Jul 30 15:51:11 2022 -0700
+
+    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.
+
+diff --git a/inflate.c b/inflate.c
+index 7be8c63..7a72897 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);
-- 
2.35.3