Fix CVE-2017-17969:

https://sourceforge.net/p/p7zip/bugs/204/
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-17969

Patch copied from Debian.

Subject: Heap-based buffer overflow in 7zip/Compress/ShrinkDecoder.cpp
Origin: vendor, https://sourceforge.net/p/p7zip/bugs/_discuss/thread/0920f369/27d7/attachment/CVE-2017-17969.patch
Forwarded: https://sourceforge.net/p/p7zip/bugs/_discuss/thread/0920f369/#27d7
Bug: https://sourceforge.net/p/p7zip/bugs/204/
Bug-Debian: https://bugs.debian.org/888297
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-17969
Author: Antoine Beaupré <anarcat@debian.org>
Reviewed-by: Salvatore Bonaccorso <carnil@debian.org>
Last-Update: 2018-02-01
Applied-Upstream: 18.00-beta

--- a/CPP/7zip/Compress/ShrinkDecoder.cpp
+++ b/CPP/7zip/Compress/ShrinkDecoder.cpp
@@ -121,8 +121,13 @@ HRESULT CDecoder::CodeReal(ISequentialIn
     {
       _stack[i++] = _suffixes[cur];
       cur = _parents[cur];
+      if (cur >= kNumItems || i >= kNumItems)
+        break;
     }
-    
+
+    if (cur >= kNumItems || i >= kNumItems)
+      break;
+
     _stack[i++] = (Byte)cur;
     lastChar2 = (Byte)cur;
 
s/?id=ab9f9b582e510e3d1133ec29242e70fca1d2997a'>refs</a><a class='active' href='/guix/log/gnu/packages/patches/icecat-102-makeicecat.patch'>log</a><a href='/guix/tree/gnu/packages/patches/icecat-102-makeicecat.patch?id=ab9f9b582e510e3d1133ec29242e70fca1d2997a'>tree</a><a href='/guix/commit/gnu/packages/patches/icecat-102-makeicecat.patch?id=ab9f9b582e510e3d1133ec29242e70fca1d2997a'>commit</a><a href='/guix/diff/gnu/packages/patches/icecat-102-makeicecat.patch?id=ab9f9b582e510e3d1133ec29242e70fca1d2997a'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/icecat-102-makeicecat.patch'>
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<tr><td><span title='2023-09-28 04:29:34 -0400'>2023-09-28</span></td><td><a href='/guix/commit/gnu/packages/patches/icecat-102-makeicecat.patch?id=c4802226650b211680e08f15808e5e4d3835af24'>gnu: icecat: Update to 115.3.0-guix0-preview1 [security fixes].</a><span class='msg-avail'>...<span class='msg-tooltip'>Includes fixes for CVE-2023-5168, CVE-2023-5169, CVE-2023-5171,
CVE-2023-5174, and CVE-2023-5176.

* gnu/packages/gnuzilla.scm (icu4c-73-promise): New variable.
(all-mozilla-locales, %icecat-base-version, %icecat-build-id): Update.
(icecat-source): Update gnuzilla commit, base version, and hashes.
(icecat-minimal)[inputs]: Use icu4c-73-promise.  Remove nss.
[native-inputs]: Use rust-cbindgen-0.24, llvm-15, clang-15, and node-lts.
[arguments]&lt;configure-flags&gt;: Comment out "--with-system-nss".
[description]: "IceCat 102" --&gt; "IceCat 115".
(%icecat-locales): Update.
(all-mozilla-102-locales, %icecat-102-base-version)
(%icecat-102-version, icecat-102-source): New variables
bound to the old values, for use by icedove.
(icedove-source): Ues 'icecat-102-source'.
(make-l10n-package)[arguments]&lt;phases&gt;: Simplify reference to
'#$locales, and thereby eliminate the unnecessary dependence on
%icedove-locales by icecat-l10n, and similarly on %icecat-locales by
icedove-l10n.
[native-inputs]: Use node-lts.
* gnu/packages/patches/icecat-makeicecat.patch: Adapt to new upstream.
* gnu/packages/patches/icecat-102-makeicecat.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
</span></span></td><td>Mark H Weaver</td></tr>