1From 7f2da4f810b429ddb7afa0e252e3d02ced0eba87 Mon Sep 17 00:00:00 2001
2From: Radovan Scasny <radovan.scasny@siemens.com>
3Date: Tue, 20 Feb 2018 12:08:13 +0100
4Subject: [PATCH] p7zip: Fix CVE-2017-17969
5
6[No upstream tracking] -- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=888297
7
8Heap-based buffer overflow in 7zip
9
10Compress/ShrinkDecoder.cpp: Heap-based buffer overflow
11in the NCompress::NShrink::CDecoder::CodeReal method
12in 7-Zip before 18.00 and p7zip allows remote attackers
13to cause a denial of service (out-of-bounds write)
14or potentially execute arbitrary code via a crafted ZIP archive.
15
16Upstream-Status: Backport [https://sourceforge.net/p/p7zip/bugs/_discuss/thread/0920f369/8316/attachment/CVE-2017-17969.patch]
17CVE: CVE-2017-17969
18Signed-off-by: Radovan Scasny <radovan.scasny@siemens.com>
19
20---
21 CPP/7zip/Compress/ShrinkDecoder.cpp | 5 +++++
22 1 file changed, 5 insertions(+)
23
24diff --git a/CPP/7zip/Compress/ShrinkDecoder.cpp b/CPP/7zip/Compress/ShrinkDecoder.cpp
25index 80b7e67..5bb0559 100644
26--- a/CPP/7zip/Compress/ShrinkDecoder.cpp
27+++ b/CPP/7zip/Compress/ShrinkDecoder.cpp
28@@ -121,7 +121,12 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
29     {
30       _stack[i++] = _suffixes[cur];
31       cur = _parents[cur];
32+	  if (cur >= kNumItems || i >= kNumItems)
33+	  	break;
34     }
35+
36+	if (cur >= kNumItems || i >= kNumItems)
37+		break;
38
39     _stack[i++] = (Byte)cur;
40     lastChar2 = (Byte)cur;
41