From 8617d83d6939754ae3a04fc2d22daa18eeea2a43 Mon Sep 17 00:00:00 2001 From: Hitendra Prajapati Date: Wed, 17 Aug 2022 10:15:57 +0530 Subject: [PATCH] CVE-2022-37434 Upstream-Status: Backport [https://github.com/madler/zlib/commit/eff308af425b67093bab25f80f1ae950166bece1 & https://github.com/madler/zlib/commit/1eb7682f845ac9e9bf9ae35bbfb3bad5dacbd91d] CVE: CVE-2022-37434 Signed-off-by: Hitendra Prajapati 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. 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. --- inflate.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/inflate.c b/inflate.c index ac333e8..cd01857 100644 --- a/inflate.c +++ b/inflate.c @@ -759,8 +759,9 @@ 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); -- 2.25.1