Partially fix CVE-2014-9112, part 1/5. Backported to 2.11. From 746f3ff670dcfcdd28fcc990e79cd6fccc7ae48d Mon Sep 17 00:00:00 2001 From: Sergey Poznyakoff Date: Mon, 01 Dec 2014 13:15:28 +0000 Subject: Fix memory overrun on reading improperly created link records. See http://lists.gnu.org/archive/html/bug-cpio/2014-11/msg00007.html * src/copyin.c (get_link_name): New function. (list_file, copyin_link): use get_link_name * tests/symlink-bad-length.at: New file. * tests/symlink-long.at: New file. * tests/Makefile.am: Add new files. * tests/testsuite.at: Likewise. --- diff --git a/src/copyin.c b/src/copyin.c index 38d809f..c502c7d 100644 --- a/src/copyin.c +++ b/src/copyin.c @@ -124,10 +124,30 @@ tape_skip_padding (int in_file_des, off_t offset) if (pad != 0) tape_toss_input (in_file_des, pad); } - + +static char * +get_link_name (struct cpio_file_stat *file_hdr, int in_file_des) +{ + off_t n = file_hdr->c_filesize + 1; + char *link_name; + + if (n == 0 || n > SIZE_MAX) + { + error (0, 0, _("%s: stored filename length too big"), file_hdr->c_name); + link_name = NULL; + } + else + { + link_name = xmalloc (n); + tape_buffered_read (link_name, in_file_des, file_hdr->c_filesize); + link_name[file_hdr->c_filesize] = '\0'; + tape_skip_padding (in_file_des, file_hdr->c_filesize); + } + return link_name; +} static void -list_file(struct cpio_file_stat* file_hdr, int in_file_des) +list_file (struct cpio_file_stat* file_hdr, int in_file_des) { if (verbose_flag) { @@ -136,21 +156,16 @@ list_file(struct cpio_file_stat* file_hdr, int in_file_des) { if (archive_format != arf_tar && archive_format != arf_ustar) { - char *link_name = NULL; /* Name of hard and symbolic links. */ - - link_name = (char *) xmalloc ((unsigned int) file_hdr->c_filesize + 1); - link_name[file_hdr->c_filesize] = '\0'; - tape_buffered_read (link_name, in_file_des, file_hdr->c_filesize); - long_format (file_hdr, link_name); - free (link_name); - tape_skip_padding (in_file_des, file_hdr->c_filesize); - return; + char *link_name = get_link_name (file_hdr, in_file_des); + if (link_name) + { + long_format (file_hdr, link_name); + free (link_name); + } } else - { - long_format (file_hdr, file_hdr->c_tar_linkname); - return; - } + long_format (file_hdr, file_hdr->c_tar_linkname); + return; } else #endif @@ -650,10 +665,7 @@ copyin_link(struct cpio_file_stat *file_ if (archive_format != arf_tar && archive_format != arf_ustar) { - link_name = (char *) xmalloc ((unsigned int) file_hdr->c_filesize + 1); - link_name[file_hdr->c_filesize] = '\0'; - tape_buffered_read (link_name, in_file_des, file_hdr->c_filesize); - tape_skip_padding (in_file_des, file_hdr->c_filesize); + link_name = get_link_name (file_hdr, in_file_des); } else { diff --git a/tests/Makefile.am b/tests/Makefile.am index 3f714d1..b4ca92d 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -52,6 +52,8 @@ TESTSUITE_AT = \ setstat04.at\ setstat05.at\ symlink.at\ + symlink-bad-length.at\ + symlink-long.at\ version.at TESTSUITE = $(srcdir)/testsuite diff --git a/tests/symlink-bad-length.at b/tests/symlink-bad-length.at new file mode 100644 index 0000000..6f804b1 --- a/dev/null +++ b/tests/symlink-bad-length.at @@ -0,0 +1,49 @@ +# Process this file with autom4te to create testsuite. -*- Autotest -*- +# Copyright (C) 2014 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 Free Software Foundation; either version 3, or (at your option) +# any later version. + +# This program 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, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +# 02110-1301 USA. + +# Cpio v2.11 did segfault with badly set symlink length. +# References: +# http://lists.gnu.org/archive/html/bug-cpio/2014-11/msg00007.html + +AT_SETUP([symlink-bad-length]) +AT_KEYWORDS([symlink-long copyout]) + +AT_DATA([ARCHIVE.base64], +[x3EjAIBAtIEtJy8nAQAAAHRUYW0FAAAADQBGSUxFAABzb21lIGNvbnRlbnQKAMdxIwBgQ/+hLScv +JwEAAAB0VEhuBQD/////TElOSwAARklMRcdxAAAAAAAAAAAAAAEAAAAAAAAACwAAAAAAVFJBSUxF +UiEhIQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA +AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= +]) + +AT_CHECK([ +base64 -d ARCHIVE.base64 > ARCHIVE || AT_SKIP_TEST +cpio -ntv < ARCHIVE +test $? -eq 2 +], +[0], +[-rw-rw-r-- 1 10029 10031 13 Nov 25 13:52 FILE +],[cpio: LINK: stored filename length too big +cpio: premature end of file +]) + +AT_CLEANUP diff --git a/tests/symlink-long.at b/tests/symlink-long.at new file mode 100644 index 0000000..d3def2d --- a/dev/null +++ b/tests/symlink-long.at @@ -0,0 +1,46 @@ +# Process this file with autom4te to create testsuite. -*- Autotest -*- +# Copyright (C) 2014 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +# 02110-1301 USA. + +# Cpio v2.11.90 changed the way symlink name is read from archive. +# References: +# http://lists.gnu.org/archive/html/bug-cpio/2014-11/msg00007.html + +AT_SETUP([symlink-long]) +AT_KEYWORDS([symlink-long copyout]) + +AT_CHECK([ + +# len(dirname) > READBUFSIZE +dirname= +for i in {1..52}; do + dirname="xxxxxxxxx/$dirname" + mkdir "$dirname" +done +ln -s "$dirname" x || AT_SKIP_TEST + +echo x | cpio -o > ar +list=`cpio -tv < ar | sed 's|.*-> ||'` +test "$list" = "$dirname" && echo success || echo fail +], +[0], +[success +],[2 blocks +2 blocks +]) + +AT_CLEANUP diff --git a/tests/testsuite.at b/tests/testsuite.at index e67689f..3b5377e 100644 --- a/tests/testsuite.at +++ b/tests/testsuite.at @@ -31,6 +31,8 @@ m4_include([version.at]) m4_include([inout.at]) m4_include([symlink.at]) +m4_include([symlink-bad-length.at]) +m4_include([symlink-long.at]) m4_include([interdir.at]) m4_include([setstat01.at]) -- cgit v0.9.0.2