File tar-1.30-CVE-2018-20482.patch of Package tar.20125
From c15c42ccd1e2377945fd0414eca1a49294bff454 Mon Sep 17 00:00:00 2001
From: Sergey Poznyakoff <gray@gnu.org>
Date: Thu, 27 Dec 2018 17:48:57 +0200
Subject: Fix CVE-2018-20482
* NEWS: Update.
* src/sparse.c (sparse_dump_region): Handle short read condition.
(sparse_extract_region,check_data_region): Fix dumped_size calculation.
Handle short read condition.
(pax_decode_header): Fix dumped_size calculation.
* tests/Makefile.am: Add new testcases.
* tests/testsuite.at: Likewise.
* tests/sptrcreat.at: New file.
* tests/sptrdiff00.at: New file.
* tests/sptrdiff01.at: New file.
---
src/sparse.c | 50 ++++++++++++++++++++++++++++++++++++------
tests/Makefile.am | 5 ++++-
tests/sptrcreat.at | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/sptrdiff00.at | 55 +++++++++++++++++++++++++++++++++++++++++++++++
tests/sptrdiff01.at | 55 +++++++++++++++++++++++++++++++++++++++++++++++
tests/testsuite.at | 5 ++++-
7 files changed, 231 insertions(+), 9 deletions(-)
create mode 100644 tests/sptrcreat.at
create mode 100644 tests/sptrdiff00.at
create mode 100644 tests/sptrdiff01.at
diff --git a/src/sparse.c b/src/sparse.c
index d41c0ea..f611200 100644
--- a/src/sparse.c
+++ b/src/sparse.c
@@ -1,6 +1,6 @@
/* Functions for dealing with sparse files
- Copyright 2003-2007, 2010, 2013-2017 Free Software Foundation, Inc.
+ Copyright 2003-2007, 2010, 2013-2018 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
@@ -427,6 +427,30 @@ sparse_dump_region (struct tar_sparse_file *file, size_t i)
bufsize);
return false;
}
+ else if (bytes_read == 0)
+ {
+ char buf[UINTMAX_STRSIZE_BOUND];
+ struct stat st;
+ size_t n;
+ if (fstat (file->fd, &st) == 0)
+ n = file->stat_info->stat.st_size - st.st_size;
+ else
+ n = file->stat_info->stat.st_size
+ - (file->stat_info->sparse_map[i].offset
+ + file->stat_info->sparse_map[i].numbytes
+ - bytes_left);
+
+ WARNOPT (WARN_FILE_SHRANK,
+ (0, 0,
+ ngettext ("%s: File shrank by %s byte; padding with zeros",
+ "%s: File shrank by %s bytes; padding with zeros",
+ n),
+ quotearg_colon (file->stat_info->orig_file_name),
+ STRINGIFY_BIGINT (n, buf)));
+ if (! ignore_failed_read_option)
+ set_exit_status (TAREXIT_DIFFERS);
+ return false;
+ }
memset (blk->buffer + bytes_read, 0, BLOCKSIZE - bytes_read);
bytes_left -= bytes_read;
@@ -464,9 +488,9 @@ sparse_extract_region (struct tar_sparse_file *file, size_t i)
return false;
}
set_next_block_after (blk);
+ file->dumped_size += BLOCKSIZE;
count = blocking_write (file->fd, blk->buffer, wrbytes);
write_size -= count;
- file->dumped_size += count;
mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
file->offset += count;
if (count != wrbytes)
@@ -598,6 +622,12 @@ check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
rdsize);
return false;
}
+ else if (bytes_read == 0)
+ {
+ report_difference (file->stat_info, _("Size differs"));
+ return false;
+ }
+
if (!zero_block_p (diff_buffer, bytes_read))
{
char begbuf[INT_BUFSIZE_BOUND (off_t)];
@@ -609,6 +639,7 @@ check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
beg += bytes_read;
}
+
return true;
}
@@ -635,6 +666,7 @@ check_data_region (struct tar_sparse_file *file, size_t i)
return false;
}
set_next_block_after (blk);
+ file->dumped_size += BLOCKSIZE;
bytes_read = safe_read (file->fd, diff_buffer, rdsize);
if (bytes_read == SAFE_READ_ERROR)
{
@@ -645,7 +677,11 @@ check_data_region (struct tar_sparse_file *file, size_t i)
rdsize);
return false;
}
- file->dumped_size += bytes_read;
+ else if (bytes_read == 0)
+ {
+ report_difference (¤t_stat_info, _("Size differs"));
+ return false;
+ }
size_left -= bytes_read;
mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
if (memcmp (blk->buffer, diff_buffer, rdsize))
@@ -1213,7 +1249,8 @@ pax_decode_header (struct tar_sparse_file *file)
union block *blk;
char *p;
size_t i;
-
+ off_t start;
+
#define COPY_BUF(b,buf,src) do \
{ \
char *endp = b->buffer + BLOCKSIZE; \
@@ -1229,7 +1266,6 @@ pax_decode_header (struct tar_sparse_file *file)
if (src == endp) \
{ \
set_next_block_after (b); \
- file->dumped_size += BLOCKSIZE; \
b = find_next_block (); \
src = b->buffer; \
endp = b->buffer + BLOCKSIZE; \
@@ -1240,8 +1276,8 @@ pax_decode_header (struct tar_sparse_file *file)
dst[-1] = 0; \
} while (0)
+ start = current_block_ordinal ();
set_next_block_after (current_header);
- file->dumped_size += BLOCKSIZE;
blk = find_next_block ();
p = blk->buffer;
COPY_BUF (blk,nbuf,p);
@@ -1278,6 +1314,8 @@ pax_decode_header (struct tar_sparse_file *file)
sparse_add_map (file->stat_info, &sp);
}
set_next_block_after (blk);
+
+ file->dumped_size += BLOCKSIZE * (current_block_ordinal () - start);
}
return true;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index fb46325..7f9294f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,6 +1,6 @@
# Makefile for GNU tar regression tests.
-# Copyright 1996-1997, 1999-2001, 2003-2007, 2009, 2012-2015 Free Software
+# Copyright 1996-1997, 1999-2001, 2003-2007, 2009, 2012-2018 Free Software
# This file is part of GNU tar.
@@ -238,6 +238,9 @@ TESTSUITE_AT = \
spmvp00.at\
spmvp01.at\
spmvp10.at\
+ sptrcreat.at\
+ sptrdiff00.at\
+ sptrdiff01.at\
time01.at\
time02.at\
truncate.at\
diff --git a/tests/sptrcreat.at b/tests/sptrcreat.at
new file mode 100644
index 0000000..8e28f0e
--- /dev/null
+++ b/tests/sptrcreat.at
@@ -0,0 +1,62 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+
+# Test suite for GNU tar.
+# Copyright 2018 Free Software Foundation, Inc.
+
+# This file is part of GNU tar.
+
+# GNU tar is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# GNU tar is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Tar up to 1.30 would loop endlessly if a sparse file had been truncated
+# while being archived (with --sparse flag).
+#
+# The bug has been assigned id CVE-2018-20482 (on the grounds that it is a
+# denial of service possibility).
+#
+# Reported by: Chris Siebenmann <cks.gnutar-01@cs.toronto.edu>
+# References: <20181226223948.781EB32008E@apps1.cs.toronto.edu>,
+# <http://lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html>
+# <https://utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug>
+# <https://nvd.nist.gov/vuln/detail/CVE-2018-20482>
+
+AT_SETUP([sparse file truncated while archiving])
+AT_KEYWORDS([truncate filechange sparse sptr sptrcreat])
+
+AT_TAR_CHECK([
+genfile --sparse --block-size=1024 --file foo \
+ 0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
+genfile --file baz
+genfile --run --checkpoint 3 --length 200m --truncate foo -- \
+ tar --checkpoint=1 \
+ --checkpoint-action=echo \
+ --checkpoint-action=sleep=1 \
+ --sparse -vcf bar foo baz
+echo Exit status: $?
+echo separator
+genfile --file foo --seek 200m --length 11575296 --pattern=zeros
+tar dvf bar],
+[1],
+[foo
+baz
+Exit status: 1
+separator
+foo
+foo: Mod time differs
+baz
+],
+[tar: foo: File shrank by 11575296 bytes; padding with zeros
+],
+[],[],[posix, gnu, oldgnu])
+
+AT_CLEANUP
diff --git a/tests/sptrdiff00.at b/tests/sptrdiff00.at
new file mode 100644
index 0000000..c410561
--- /dev/null
+++ b/tests/sptrdiff00.at
@@ -0,0 +1,55 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright 2018 Free Software Foundation, Inc.
+#
+# This file is part of GNU tar.
+#
+# GNU tar is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# GNU tar is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# While fixing CVE-2018-20482 (see sptrcreat.at) it has been discovered
+# that similar bug exists in file checking code (tar d).
+# This test case checks if tar correctly handles a short read condition
+# appearing in check_sparse_region.
+
+AT_SETUP([file truncated in sparse region while comparing])
+AT_KEYWORDS([truncate filechange sparse sptr sptrdiff diff])
+
+# This triggers short read in check_sparse_region.
+AT_TAR_CHECK([
+genfile --sparse --block-size=1024 --file foo \
+ 0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
+genfile --file baz
+echo creating
+tar --sparse -vcf bar foo baz
+echo comparing
+genfile --run --checkpoint 3 --length 200m --truncate foo -- \
+ tar --checkpoint=1 \
+ --checkpoint-action=echo='Write checkpoint %u' \
+ --checkpoint-action=sleep=1 \
+ --sparse -vdf bar
+],
+[1],
+[creating
+foo
+baz
+comparing
+foo
+foo: Size differs
+baz
+],
+[],
+[],[],[posix, gnu, oldgnu])
+
+AT_CLEANUP
diff --git a/tests/sptrdiff01.at b/tests/sptrdiff01.at
new file mode 100644
index 0000000..2da2267
--- /dev/null
+++ b/tests/sptrdiff01.at
@@ -0,0 +1,55 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright 2018 Free Software Foundation, Inc.
+#
+# This file is part of GNU tar.
+#
+# GNU tar is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# GNU tar is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# While fixing CVE-2018-20482 (see sptrcreat.at) it has been discovered
+# that similar bug exists in file checking code (tar d).
+# This test case checks if tar correctly handles a short read condition
+# appearing in check_data_region.
+
+AT_SETUP([file truncated in data region while comparing])
+AT_KEYWORDS([truncate filechange sparse sptr sptrdiff diff])
+
+# This triggers short read in check_data_region.
+AT_TAR_CHECK([
+genfile --sparse --block-size=1024 --file foo \
+ 0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
+genfile --file baz
+echo creating
+tar --sparse -vcf bar foo baz
+echo comparing
+genfile --run --checkpoint 5 --length 221278210 --truncate foo -- \
+ tar --checkpoint=1 \
+ --checkpoint-action=echo='Write checkpoint %u' \
+ --checkpoint-action=sleep=1 \
+ --sparse -vdf bar
+],
+[1],
+[creating
+foo
+baz
+comparing
+foo
+foo: Size differs
+baz
+],
+[],
+[],[],[posix, gnu, oldgnu])
+
+AT_CLEANUP
diff --git a/tests/testsuite.at b/tests/testsuite.at
index dcccc7b..0f5cca3 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -1,7 +1,7 @@
# Process this file with autom4te to create testsuite. -*- Autotest -*-
# Test suite for GNU tar.
-# Copyright 2004-2008, 2010-2017 Free Software Foundation, Inc.
+# Copyright 2004-2008, 2010-2018 Free Software Foundation, Inc.
# This file is part of GNU tar.
@@ -416,6 +416,9 @@ m4_include([sparsemv.at])
m4_include([spmvp00.at])
m4_include([spmvp01.at])
m4_include([spmvp10.at])
+m4_include([sptrcreat.at])
+m4_include([sptrdiff00.at])
+m4_include([sptrdiff01.at])
AT_BANNER([Updates])
m4_include([update.at])
--
cgit v1.0-41-gc330
