From 6e06b1c89dd0d16f74894eac4cfc1327a06ee4a0 Mon Sep 17 00:00:00 2001
From: Tim Kientzle <kientzle@acm.org>
Date: Sat, 10 Jan 2015 12:24:58 -0800
Subject: [PATCH] Fix a potential crash issue discovered by Alexander
Cherepanov:
It seems bsdtar automatically handles stacked compression. This is a
nice feature but it could be problematic when it's completely
unlimited. Most clearly it's illustrated with quines:
$ curl -sRO http://www.maximumcompression.com/selfgz.gz
$ (ulimit -v 10000000 && bsdtar -tvf selfgz.gz)
bsdtar: Error opening archive: Can't allocate data for gzip decompression
Without ulimit, bsdtar will eat all available memory. This could also
be a problem for other applications using libarchive.
---
Makefile.am | 2 ++
libarchive/archive_read.c | 7 ++--
libarchive/test/CMakeLists.txt | 1 +
libarchive/test/test_read_too_many_filters.c | 45 ++++++++++++++++++++++++
libarchive/test/test_read_too_many_filters.gz.uu | 15 ++++++++
5 files changed, 68 insertions(+), 2 deletions(-)
create mode 100644 libarchive/test/test_read_too_many_filters.c
create mode 100644 libarchive/test/test_read_too_many_filters.gz.uu
diff --git a/Makefile.am b/Makefile.am
index 3fa2d22..d6e40a2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -432,6 +432,7 @@ libarchive_test_SOURCES= \
libarchive/test/test_read_pax_truncated.c \
libarchive/test/test_read_position.c \
libarchive/test/test_read_set_format.c \
+ libarchive/test/test_read_too_many_filters.c \
libarchive/test/test_read_truncated.c \
libarchive/test/test_read_truncated_filter.c \
libarchive/test/test_sparse_basic.c \
@@ -693,6 +694,7 @@ libarchive_test_EXTRA_DIST=\
libarchive/test/test_read_splitted_rar_ab.uu \
libarchive/test/test_read_splitted_rar_ac.uu \
libarchive/test/test_read_splitted_rar_ad.uu \
+ libarchive/test/test_read_too_many_filters.gz.uu \
libarchive/test/test_splitted_rar_seek_support_aa.uu \
libarchive/test/test_splitted_rar_seek_support_ab.uu \
libarchive/test/test_splitted_rar_seek_support_ac.uu \
diff --git a/libarchive/archive_read.c b/libarchive/archive_read.c
index 048c316..f8dde89 100644
--- a/libarchive/archive_read.c
+++ b/libarchive/archive_read.c
@@ -544,13 +544,13 @@ archive_read_open1(struct archive *_a)
static int
choose_filters(struct archive_read *a)
{
- int number_bidders, i, bid, best_bid;
+ int number_bidders, i, bid, best_bid, n;
struct archive_read_filter_bidder *bidder, *best_bidder;
struct archive_read_filter *filter;
ssize_t avail;
int r;
- for (;;) {
+ for (n = 0; n < 25; ++n) {
number_bidders = sizeof(a->bidders) / sizeof(a->bidders[0]);
best_bid = 0;
@@ -596,6 +596,9 @@ choose_filters(struct archive_read *a)
return (ARCHIVE_FATAL);
}
}
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Input requires too many filters for decoding");
+ return (ARCHIVE_FATAL);
}
/*
diff --git a/libarchive/test/CMakeLists.txt b/libarchive/test/CMakeLists.txt
index d2eb2c2..6ac850d 100644
--- a/libarchive/test/CMakeLists.txt
+++ b/libarchive/test/CMakeLists.txt
@@ -147,6 +147,7 @@ IF(ENABLE_TEST)
test_read_pax_truncated.c
test_read_position.c
test_read_set_format.c
+ test_read_too_many_filters.c
test_read_truncated.c
test_read_truncated_filter.c
test_sparse_basic.c
diff --git a/libarchive/test/test_read_too_many_filters.c b/libarchive/test/test_read_too_many_filters.c
new file mode 100644
index 0000000..37cab24
--- /dev/null
+++ b/libarchive/test/test_read_too_many_filters.c
@@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 2003-2008,2015 Tim Kientzle
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "test.h"
+
+DEFINE_TEST(test_read_too_many_filters)
+{
+ const char *name = "test_read_too_many_filters.gz";
+ struct archive *a;
+ int r;
+
+ assert((a = archive_read_new()) != NULL);
+ r = archive_read_support_filter_gzip(a);
+ if (r == ARCHIVE_WARN) {
+ skipping("gzip reading not fully supported on this platform");
+ }
+ assertEqualIntA(a, ARCHIVE_OK, archive_read_support_format_all(a));
+ extract_reference_file(name);
+ assertEqualIntA(a, ARCHIVE_FATAL,
+ archive_read_open_filename(a, name, 200));
+
+ assertEqualInt(ARCHIVE_OK, archive_read_close(a));
+ assertEqualInt(ARCHIVE_OK, archive_read_free(a));
+}
diff --git a/libarchive/test/test_read_too_many_filters.gz.uu b/libarchive/test/test_read_too_many_filters.gz.uu
new file mode 100644
index 0000000..6bf6614
--- /dev/null
+++ b/libarchive/test/test_read_too_many_filters.gz.uu
@@ -0,0 +1,15 @@
+This is a valid gzip file that decompresses to itself, from
+ http://www.maximumcompression.com/selfgz.gz
+
+This is used in test_read_too_many_filters to try to
+crash libarchive by forcing it to spawn an unending
+list of gunzip filters.
+
+begin 644 test_read_too_many_filters.gz
+M'XL(`````````P`/`/#_'XL(`````````P`/`/#_````__\```#__X)QH5P`
+M`!X`X?\```#__P```/__@G&A7```'@#A_P```/__````__\```#__P```/__
+M````__\```#__\(FAF`!`!0`Z_\```#__P```/__PB:&8`$`%`#K_\(FAF`!
+M`!0`Z_^9(#6-B"@Q,C,T`K/`+```%`#K_P*SP"P``!0`Z_]"B"'$`````/__
+>`P!#2DTAT@```$*((<0`````__\#`$-*32'2````
+`
+end
--
2.7.4