[Bug 2018293] [NEW] [UBUNTU 20.04] Crash in zlib deflateBound() function on s390x

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You have been subscribed to a public bug by Frank Heimes (fheimes):

SRU Justification:
==================

[ Impact ]

 * The zlib deflateBound() function can crash on s390x,
   if called before deflateInit().

 * The solution is that zlib on s390x needs to support
   calling deflateBound() always before deflateInit().

[ Test Plan ]

 * It's suggested to do a more overall or e2e test
   and run the zlib-ng test suite against the system zlib
   as follows:
   $ git clone https://github.com/zlib-ng/zlib-ng.git
   $ cd zlib-ng
   $ cmake -DZLIB_COMPAT=ON -DZLIBNG_ENABLE_TESTS=OFF -DBUILD_SHARED_LIBS=ON -DWITH_DFLTCC_DEFLATE=ON -DWITH_DFLTCC_INFLATE=ON .
   $ make gtest_zlib
   $ ldd gtest_zlib
     libz.so.1 => /lib/s390x-linux-gnu/libz.so.1 (0x000003fff7e00000)
   $ ./gtest_zlib

[ Where problems could occur ]

 * The only (single line) modification is in the if condition
   of the define DEFLATE_BOUND_ADJUST_COMPLEN statement in
   deflate.c.

 * Things can go wrong if the condition (or logic) is wrong,

 * or if other parts of the code are coded against the old behavior
   and are still expecting it.

 * The likely outcome would be still a crash
   or an unexpected behavior.

[ Other Info ]

 * Getting this into mantic first,
   before the SRU down to focal is done.
__________

Problem Description:
zlib deflateBound() function can crash on s390x when called before deflateInit().

Solution:
zlib on s390x needs to support calling deflateBound() before deflateInit().

The fix is squashed into the latest DFLTCC PR:
https://github.com/madler/zlib/pull/410

Diff:
https://github.com/madler/zlib/compare/113203437eda67261848b14b6c80a33ff7e33d34..f6d382a91a4e7d88b9b12ce0ecdffb1783878160

** Affects: ubuntu-z-systems
     Importance: Medium
     Assignee: Skipper Bug Screeners (skipper-screen-team)
         Status: In Progress

** Affects: zlib (Ubuntu)
     Importance: Medium
     Assignee: Frank Heimes (fheimes)
         Status: In Progress

** Affects: zlib (Ubuntu Focal)
     Importance: Undecided
         Status: New

** Affects: zlib (Ubuntu Jammy)
     Importance: Undecided
         Status: New

** Affects: zlib (Ubuntu Lunar)
     Importance: Undecided
         Status: New

** Affects: zlib (Ubuntu Mantic)
     Importance: Medium
     Assignee: Frank Heimes (fheimes)
         Status: In Progress


** Tags: architecture-s3903164 bugnameltc-202410 patch severity-medium targetmilestone-inin---
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[UBUNTU 20.04] Crash in zlib deflateBound() function on s390x
https://bugs.launchpad.net/bugs/2018293
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