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.
Bug: http://b/242544249
Test: TreeHugger
Change-Id: I648db086d1e93b9f8b803dd106990afb8cbd2a85
(cherry picked from commit d738ba585e361ec65a29716931f4cff3eab2b81a)
Merged-In: I648db086d1e93b9f8b803dd106990afb8cbd2a85
diff --git a/third_party/zlib/contrib/optimizations/inflate.c b/third_party/zlib/contrib/optimizations/inflate.c
index 4841cd9..bb223af 100644
--- a/third_party/zlib/contrib/optimizations/inflate.c
+++ b/third_party/zlib/contrib/optimizations/inflate.c
@@ -772,8 +772,9 @@
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);
diff --git a/third_party/zlib/inflate.c b/third_party/zlib/inflate.c
index 7543c33..a9e2ddd 100644
--- a/third_party/zlib/inflate.c
+++ b/third_party/zlib/inflate.c
@@ -761,8 +761,9 @@
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);