Skip to content

L
linux
Switch branch/tag
  1. 02 Sep, 2014 3 commits
  3. 05 Aug, 2014 1 commit
  5. 03 Aug, 2014 1 commit
  7. 02 Aug, 2014 1 commit
  9. 01 Aug, 2014 4 commits
    • Paul Moore's avatar
      netlabel: shorter names for the NetLabel catmap funcs/structs · 4fbe63d1
      Paul Moore authored 
      Historically the NetLabel LSM secattr catmap functions and data
structures have had very long names which makes a mess of the NetLabel
code and anyone who uses NetLabel.  This patch renames the catmap
functions and structures from "*_secattr_catmap_*" to just "*_catmap_*"
which improves things greatly.

There are no substantial code or logic changes in this patch.
Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
Tested-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
      4fbe63d1
    • Paul Moore's avatar
      netlabel: fix the catmap walking functions · d960a618
      Paul Moore authored 
      The two NetLabel LSM secattr catmap walk functions didn't handle
certain edge conditions correctly, causing incorrect security labels
to be generated in some cases.  This patch corrects these problems and
converts the functions to use the new _netlbl_secattr_catmap_getnode()
function in order to reduce the amount of repeated code.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
Tested-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
      d960a618
    • Paul Moore's avatar
      netlabel: fix the horribly broken catmap functions · 4b8feff2
      Paul Moore authored 
      The NetLabel secattr catmap functions, and the SELinux import/export
glue routines, were broken in many horrible ways and the SELinux glue
code fiddled with the NetLabel catmap structures in ways that we
probably shouldn't allow.  At some point this "worked", but that was
likely due to a bit of dumb luck and sub-par testing (both inflicted
by yours truly).  This patch corrects these problems by basically
gutting the code in favor of something less obtuse and restoring the
NetLabel abstractions in the SELinux catmap glue code.

Everything is working now, and if it decides to break itself in the
future this code will be much easier to debug than the code it
replaces.

One noteworthy side effect of the changes is that it is no longer
necessary to allocate a NetLabel catmap before calling one of the
NetLabel APIs to set a bit in the catmap.  NetLabel will automatically
allocate the catmap nodes when needed, resulting in less allocations
when the lowest bit is greater than 255 and less code in the LSMs.

Cc: stable@vger.kernel.org
Reported-by: default avatarChristian Evans <frodox@zoho.com>
Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
Tested-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
      4b8feff2
    • Paul Moore's avatar
      netlabel: fix a problem when setting bits below the previously lowest bit · 41c3bd20
      Paul Moore authored 
      The NetLabel category (catmap) functions have a problem in that they
assume categories will be set in an increasing manner, e.g. the next
category set will always be larger than the last.  Unfortunately, this
is not a valid assumption and could result in problems when attempting
to set categories less than the startbit in the lowest catmap node.
In some cases kernel panics and other nasties can result.

This patch corrects the problem by checking for this and allocating a
new catmap node instance and placing it at the front of the list.

Cc: stable@vger.kernel.org
Reported-by: default avatarChristian Evans <frodox@zoho.com>
Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
Tested-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
      41c3bd20
  11. 31 Jul, 2014 1 commit
  13. 29 Jul, 2014 7 commits
  15. 28 Jul, 2014 4 commits
  17. 26 Jul, 2014 2 commits
  19. 25 Jul, 2014 4 commits
  21. 24 Jul, 2014 3 commits
    • Eric Paris's avatar
      CAPABILITIES: remove undefined caps from all processes · 7d8b6c63
      Eric Paris authored 
      This is effectively a revert of 7b9a7ec5
plus fixing it a different way...

We found, when trying to run an application from an application which
had dropped privs that the kernel does security checks on undefined
capability bits.  This was ESPECIALLY difficult to debug as those
undefined bits are hidden from /proc/$PID/status.

Consider a root application which drops all capabilities from ALL 4
capability sets.  We assume, since the application is going to set
eff/perm/inh from an array that it will clear not only the defined caps
less than CAP_LAST_CAP, but also the higher 28ish bits which are
undefined future capabilities.

The BSET gets cleared differently.  Instead it is cleared one bit at a
time.  The problem here is that in security/commoncap.c::cap_task_prctl()
we actually check the validity of a capability being read.  So any task
which attempts to 'read all things set in bset' followed by 'unset all
things set in bset' will not even attempt to unset the undefined bits
higher than CAP_LAST_CAP.

So the 'parent' will look something like:
CapInh:	0000000000000000
CapPrm:	0000000000000000
CapEff:	0000000000000000
CapBnd:	ffffffc000000000

All of this 'should' be fine.  Given that these are undefined bits that
aren't supposed to have anything to do with permissions.  But they do...

So lets now consider a task which cleared the eff/perm/inh completely
and cleared all of the valid caps in the bset (but not the invalid caps
it couldn't read out of the kernel).  We know that this is exactly what
the libcap-ng library does and what the go capabilities library does.
They both leave you in that above situation if you try to clear all of
you capapabilities from all 4 sets.  If that root task calls execve()
the child task will pick up all caps not blocked by the bset.  The bset
however does not block bits higher than CAP_LAST_CAP.  So now the child
task has bits in eff which are not in the parent.  These are
'meaningless' undefined bits, but still bits which the parent doesn't
have.

The problem is now in cred_cap_issubset() (or any operation which does a
subset test) as the child, while a subset for valid cap bits, is not a
subset for invalid cap bits!  So now we set durring commit creds that
the child is not dumpable.  Given it is 'more priv' than its parent.  It
also means the parent cannot ptrace the child and other stupidity.

The solution here:
1) stop hiding capability bits in status
	This makes debugging easier!

2) stop giving any task undefined capability bits.  it's simple, it you
don't put those invalid bits in CAP_FULL_SET you won't get them in init
and you won't get them in any other task either.
	This fixes the cap_issubset() tests and resulting fallout (which
	made the init task in a docker container untraceable among other
	things)

3) mask out undefined bits when sys_capset() is called as it might use
~0, ~0 to denote 'all capabilities' for backward/forward compatibility.
	This lets 'capsh --caps="all=eip" -- -c /bin/bash' run.

4) mask out undefined bit when we read a file capability off of disk as
again likely all bits are set in the xattr for forward/backward
compatibility.
	This lets 'setcap all+pe /bin/bash; /bin/bash' run
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Dan Walsh <dwalsh@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
      7d8b6c63
    • James Morris's avatar
      Merge tag 'keys-next-20140722' of... · 4ca332e1
      James Morris authored 
      Merge tag 'keys-next-20140722' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
      4ca332e1
    • Tetsuo Handa's avatar
      commoncap: don't alloc the credential unless needed in cap_task_prctl · 6d6f3328
      Tetsuo Handa authored 
      In function cap_task_prctl(), we would allocate a credential
unconditionally and then check if we support the requested function.
If not we would release this credential with abort_creds() by using
RCU method. But on some archs such as powerpc, the sys_prctl is heavily
used to get/set the floating point exception mode. So the unnecessary
allocating/releasing of credential not only introduce runtime overhead
but also do cause OOM due to the RCU implementation.

This patch removes abort_creds() from cap_task_prctl() by calling
prepare_creds() only when we need to modify it.
Reported-by: default avatarKevin Hao <haokexin@gmail.com>
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: default avatarPaul Moore <paul@paul-moore.com>
Acked-by: default avatarSerge E. Hallyn <serge.hallyn@ubuntu.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
      6d6f3328
  23. 22 Jul, 2014 9 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7