Commit Graph

14 Commits

Author SHA1 Message Date
Michal Nazarewicz c725ee54c3 gen_init_cpio: avoid NULL pointer dereference and rework env expanding
getenv() may return NULL if given environment variable does not exist
which leads to NULL dereference when calling strncat.

Besides that, the environment variable name was copied to a temporary
env_var buffer, but this copying can be avoided by simply using the input
string.

Lastly, the whole loop can be greatly simplified by using the snprintf
function instead of the playing with strncat.

 By the way, the current implementation allows a recursive variable
 expansion, as in:

   $ echo 'out ${A} out ' | A='a ${B} a' B=b /tmp/a
   out a b a out

 I'm assuming this is just a side effect and not a conscious decision
 (especially as this may lead to infinite loop), but I didn't want to
 change this behaviour without consulting.

 If the current behaviour is deamed incorrect, I'll be happy to send
 a patch without recursive processing.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jesper Juhl <jj@codesealer.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:12 +09:00
Jesper Juhl 59dbaf0415 gen_init_cpio: remove redundant empty line
Just a completely trivial patch to remove a completely redundant blank
line from usr/gen_init_cpio.c

Signed-off-by: Jesper Juhl <jj@codesealer.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-19 14:09:36 +01:00
Kees Cook 20f1de659b gen_init_cpio: avoid stack overflow when expanding
Fix possible overflow of the buffer used for expanding environment
variables when building file list.

In the extremely unlikely case of an attacker having control over the
environment variables visible to gen_init_cpio, control over the
contents of the file gen_init_cpio parses, and gen_init_cpio was built
without compiler hardening, the attacker can gain arbitrary execution
control via a stack buffer overflow.

  $ cat usr/crash.list
  file foo ${BIG}${BIG}${BIG}${BIG}${BIG}${BIG} 0755 0 0
  $ BIG=$(perl -e 'print "A" x 4096;') ./usr/gen_init_cpio usr/crash.list
  *** buffer overflow detected ***: ./usr/gen_init_cpio terminated

This also replaces the space-indenting with tabs.

Patch based on existing fix extracted from grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: PaX Team <pageexec@freemail.hu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-25 14:37:53 -07:00
Michal Marek a8b8017c34 initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries
gen_init_cpio gets the current time and uses it for each symlink,
special file, and directory.  Grab the current time once and make it
possible to override it with the KBUILD_BUILD_TIMESTAMP variable for
reproducible builds.

Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-04-18 14:27:52 +02:00
Andrew Morton a3c888fcda gen_init_cpio: checkpatch fixes
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-01-05 23:49:53 +01:00
Jesper Juhl 96aebafa63 gen_init_cpio: Avoid race between call to stat() and call to open()
In usr/gen_init_cpio.c::cpio_mkfile() a call to stat() is made based on
pathname, subsequently the file is open()'ed and then the value of the
initial stat() call is used to allocate a buffer. This is not safe since
the file may change between the call to stat() and the call to open().
Safer to just open() the file and then do fstat() using the filedescriptor
returned by open.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-12-29 15:06:54 +01:00
Thomas Chou 43f901fbc8 gen_init_cpio: remove leading `/' from file names
When we extracted the generated cpio archive using "cpio -id" command,
it complained,

cpio: Removing leading `/' from member names
var/run
cpio: Removing leading `/' from member names
var/lib
cpio: Removing leading `/' from member names
var/lib/misc

It is worse with the latest "cpio" or "pax", which tries to overwrite
the host file system with the leading '/'.

So the leading '/' of file names should be removed. This is consistent
with the initramfs come with major distributions such as Fedora or
Debian, etc.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Mike Frysinger<vapier@gentoo.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-12-02 14:28:50 +01:00
Mike Frysinger 6d87fea4dd gen_init_cpio: fixed fwrite warning
On compilers with security warnings enabled by default, we get:

usr/gen_init_cpio.c: In function ‘cpio_mkfile’:
usr/gen_init_cpio.c:357: warning: ignoring return value of ‘fwrite’,
                                  declared with attribute warn_unused_result

So check the return value and handle errors accordingly.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2009-12-12 13:08:17 +01:00
Trevor Keith 5c72513843 Fix all -Wmissing-prototypes warnings in x86 defconfig
Signed-off-by: Trevor Keith <tsrk@tsrk.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:28 -07:00
Sally, Gene 3b1ec9fb81 kbuild: gen_init_cpio expands shell variables in file names
Modify gen_init_cpio so that lines that specify files can contain
what looks like a shell variable that's expanded during processing.

For example:

   file /sbin/kinit ${RFS_BASE}/usr/src/klibc/kinit/kinit 0755 0 0

given RFS_BASE is "/some/directory" in the environment

would be expanded to

   file /sbin/kinit /some/directory/usr/src/klibc/kinit/kinit 0755 0 0

If several environment variables appear in a line, they are all expanded
with processing happening from left to right.
Undefined variables expand to a null string.
Syntax errors stop processing, letting the existing error handling
show the user offending line.

This patch helps embedded folks who frequently create several
RFS directories and then switch between them as they're tuning
an initramfs.

Signed-off-by: gene.sally@timesys.com
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-12-03 21:32:03 +01:00
Mike Frysinger f2434ec1e0 kbuild: add support for reading stdin with gen_init_cpio
Treat an argument of "-" as meaning "read stdin for cpio files" so
gen_init_cpio can be piped into.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-07-16 21:15:52 +02:00
Luciano Rocha 24fa509614 [PATCH] usr/gen_init_cpio.c: support for hard links
Extend usr/gen_init_cpio.c "file" entry, adding support for hard links.

Previous format:
file <name> <location> <mode> <uid> <gid>

New format:
file <name> <location> <mode> <uid> <gid> [<hard links>]

The hard links specification is optional, keeping the previous
behaviour.

All hard links are defined sequentially in the resulting cpio and the
file data is present only in the last link. This is the behaviour of
GNU's cpio and is supported by the kernel initramfs extractor.

Signed-off-by: Luciano Rocha <strange@nsk.no-ip.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:25 -08:00
Jesper Juhl aa1e816fc9 [PATCH] Fix potential NULL pointer deref in gen_init_cpio
Fix potential NULL pointer deref in gen_init_cpio.c spotted by coverity
checker.  This fixes coverity bug #86

Without this patch we risk dereferencing a NULL `type' in the
"if ('\n' == *type) {" line.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-19 09:13:52 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00