On Saturday 22 of November 2014 23:37:07 Michal Zalewski wrote: > Please see this test case for cpio 2.11: > > http://lcamtuf.coredump.cx/afl/vulns/lesspipe-cpio-bad-write.cpio
Possible fix attached. Pavel
>From dd3c5e3d4b44155807a6466385b98401aaca0f21 Mon Sep 17 00:00:00 2001 From: Pavel Raiskup <prais...@redhat.com> Date: Tue, 25 Nov 2014 13:21:55 +0100 Subject: [PATCH] copyin: buffer-alloc the link name References: http://lists.gnu.org/archive/html/bug-cpio/2014-11/msg00007.html * gnulib.modules: Include 'obstack' module. * src/copyin.c: Define obstack_chunk_alloc and obstack_chunk_free to be used by <obstack.h> include. (read_link_name_from_file, get_link_name): New local functions which use buffering for link name reading. (list_file): Use get_link_name(). (copyin_link): Use get_link_name(). * tests/symlink-bad-length.at: New testcase. * tests/symlink-long.at: Likewise. * tests/Makefile.am: Mention new test-cases. * tests/testsuite.at: Likewise. --- gnulib.modules | 1 + src/copyin.c | 104 +++++++++++++++++++++++++++----------------- tests/Makefile.am | 2 + tests/symlink-bad-length.at | 48 ++++++++++++++++++++ tests/symlink-long.at | 46 ++++++++++++++++++++ tests/testsuite.at | 2 + 6 files changed, 162 insertions(+), 41 deletions(-) create mode 100644 tests/symlink-bad-length.at create mode 100644 tests/symlink-long.at diff --git a/gnulib.modules b/gnulib.modules index f165870..4c99bc0 100644 --- a/gnulib.modules +++ b/gnulib.modules @@ -17,6 +17,7 @@ gitlog-to-changelog hash inttypes lchown +obstack progname safe-read savedir diff --git a/src/copyin.c b/src/copyin.c index 38d809f..faa3dca 100644 --- a/src/copyin.c +++ b/src/copyin.c @@ -32,6 +32,10 @@ # include <fnmatch.h> #endif +#define obstack_chunk_alloc malloc +#define obstack_chunk_free free +#include <obstack.h> + #ifndef HAVE_LCHOWN # define lchown(f,u,g) 0 #endif @@ -125,36 +129,66 @@ tape_skip_padding (int in_file_des, off_t offset) tape_toss_input (in_file_des, pad); } +#ifdef CP_IFLNK +static char * +read_link_name_from_file (struct cpio_file_stat *file_hdr, + int in_file_des) +{ +#define READBUFFSIZE 512 + char buff[READBUFFSIZE]; + off_t chunk, remains = file_hdr->c_filesize; + char *link_name = 0; + struct obstack stk; + + obstack_init (&stk); + + while (remains > 0) + { + chunk = remains < READBUFFSIZE ? remains : READBUFFSIZE; + tape_buffered_read (buff, in_file_des, chunk); + obstack_grow (&stk, buff, chunk); + remains -= chunk; + } + + obstack_1grow (&stk, '\0'); + link_name = xstrdup (obstack_finish (&stk)); + + obstack_free (&stk, NULL); + tape_skip_padding (in_file_des, file_hdr->c_filesize); + + return link_name; +#undef READBUFFSIZE +} +#endif /* CP_IFLNK */ + +static char * +get_link_name (struct cpio_file_stat* file_hdr, int in_file_des) +{ + char *link_name = NULL; + +#ifdef CP_IFLNK + if ((file_hdr->c_mode & CP_IFMT) == CP_IFLNK) + { + if (archive_format != arf_tar && archive_format != arf_ustar) + link_name = read_link_name_from_file (file_hdr, in_file_des); + else + link_name = xstrdup (file_hdr->c_tar_linkname); + } +#endif + + return link_name; +} + static void list_file(struct cpio_file_stat* file_hdr, int in_file_des) { if (verbose_flag) { -#ifdef CP_IFLNK - if ((file_hdr->c_mode & CP_IFMT) == CP_IFLNK) - { - 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; - } - else - { - long_format (file_hdr, file_hdr->c_tar_linkname); - return; - } - } - else -#endif - long_format (file_hdr, (char *) 0); + char *linkname = get_link_name (file_hdr, in_file_des); + long_format (file_hdr, linkname); + free (linkname); + return; } else { @@ -635,24 +669,12 @@ copyin_link(struct cpio_file_stat *file_hdr, int in_file_des) char *link_name = NULL; /* Name of hard and symbolic links. */ int res; /* Result of various function calls. */ - if (archive_format != arf_tar && archive_format != arf_ustar) + /* make sure get_link_name to make sure the buffer is moved correctly */ + link_name = get_link_name (file_hdr, in_file_des); + if (to_stdout_option) { - if (to_stdout_option) - { - tape_toss_input (in_file_des, file_hdr->c_filesize); - tape_skip_padding (in_file_des, file_hdr->c_filesize); - return; - } - 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); - } - else - { - if (to_stdout_option) - return; - link_name = xstrdup (file_hdr->c_tar_linkname); + free (link_name); + return; } res = UMASKED_SYMLINK (link_name, file_hdr->c_name, diff --git a/tests/Makefile.am b/tests/Makefile.am index 3f714d1..b4ca92d 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -51,6 +51,8 @@ TESTSUITE_AT = \ setstat04.at\ setstat05.at\ symlink.at\ + symlink-bad-length.at\ + symlink-long.at\ symlink-to-stdout.at\ version.at diff --git a/tests/symlink-bad-length.at b/tests/symlink-bad-length.at new file mode 100644 index 0000000..88677a3 --- /dev/null +++ b/tests/symlink-bad-length.at @@ -0,0 +1,48 @@ +# 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 -tv < ARCHIVE +test $? -eq 2 +], +[0], +[-rw-rw-r-- 1 cpio_use cpio_use 13 Nov 25 12:52 FILE +],[cpio: premature end of file +]) + +AT_CLEANUP diff --git a/tests/symlink-long.at b/tests/symlink-long.at new file mode 100644 index 0000000..d3def2d --- /dev/null +++ b/tests/symlink-long.at @@ -0,0 +1,46 @@ +# Process this file with autom4te to create testsuite. -*- Autotest -*- +# Copyright (C) 2014 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +# 02110-1301 USA. + +# Cpio v2.11.90 changed the way symlink name is read from archive. +# References: +# http://lists.gnu.org/archive/html/bug-cpio/2014-11/msg00007.html + +AT_SETUP([symlink-long]) +AT_KEYWORDS([symlink-long copyout]) + +AT_CHECK([ + +# len(dirname) > READBUFSIZE +dirname= +for i in {1..52}; do + dirname="xxxxxxxxx/$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 @@ -32,6 +32,8 @@ 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([symlink-to-stdout.at]) m4_include([interdir.at]) -- 1.9.3
