Extracted from a patch in Fedora.
http://pkgs.fedoraproject.org/cgit/unzip.git/tree/unzip-6.0-heap-overflow-infloop.patch?id=d18f821e
From bd150334fb4084f5555a6be26b015a0671cb5b74 Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Tue, 22 Sep 2015 18:52:23 +0200
Subject: [PATCH 3/3] extract: prevent unsigned overflow on invalid input
Suggested-by: Stefan Cornelius
---
extract.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/extract.c b/extract.c
index 29db027..b9ae667 100644
--- a/extract.c
+++ b/extract.c
@@ -1257,8 +1257,17 @@ static int extract_or_test_entrylist(__G__ numchunk,
if (G.lrec.compression_method == STORED) {
zusz_t csiz_decrypted = G.lrec.csize;
- if (G.pInfo->encrypted)
+ if (G.pInfo->encrypted) {
+ if (csiz_decrypted <= 12) {
+ /* handle the error now to prevent unsigned overflow */
+ Info(slide, 0x401, ((char *)slide,
+ LoadFarStringSmall(ErrUnzipNoFile),
+ LoadFarString(InvalidComprData),
+ LoadFarStringSmall2(Inflate)));
+ return PK_ERR;
+ }
csiz_decrypted -= 12;
+ }
if (G.lrec.ucsize != csiz_decrypted) {
Info(slide, 0x401, ((char *)slide,
LoadFarStringSmall2(WrnStorUCSizCSizDiff),
--
2.5.2
