From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Wed, 19 Apr 2023 14:03:18 +0000 (+0200)
Subject: IBM zSystems: Fix calling deflateBound() before deflateInit()
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2F2.0.x;p=thirdparty%2Fzlib-ng.git

IBM zSystems: Fix calling deflateBound() before deflateInit()

Even though zlib officialy forbids calling deflateBound() before
deflateInit(), Firefox does this anyway, and it happens to work [1],
but unfortunately not with DFLTCC [2], because the DFLTCC code assumes
that the deflate state is allocated, and segfaults when it isn't.

Bow down before Hyrum's Law and add deflateStateCheck() to
DEFLATE_BOUND_ADJUST_COMPLEN().

[1] https://searchfox.org/mozilla-esr102/source/dom/script/ScriptCompression.cpp#97
[2] https://bugzilla.suse.com/show_bug.cgi?id=1210593
---

diff --git a/arch/s390/dfltcc_deflate.h b/arch/s390/dfltcc_deflate.h
index 218e5946..1081b274 100644
--- a/arch/s390/dfltcc_deflate.h
+++ b/arch/s390/dfltcc_deflate.h
@@ -40,7 +40,7 @@ int Z_INTERNAL dfltcc_deflate_get_dictionary(PREFIX3(streamp) strm, unsigned cha
 
 #define DEFLATE_BOUND_ADJUST_COMPLEN(strm, complen, source_len) \
     do { \
-        if (dfltcc_can_deflate((strm))) \
+        if (deflateStateCheck((strm)) || dfltcc_can_deflate((strm))) \
             (complen) = DEFLATE_BOUND_COMPLEN(source_len); \
     } while (0)