Commit Graph

200 Commits

Author SHA1 Message Date
John Baldwin
7e9e371f2d Use the refcount API to manage the reference count for user credentials
rather than using pool mutexes.

Tested on:	i386, alpha, sparc64
2005-09-27 18:09:42 +00:00
Robert Watson
babe9a2bb3 Introduce p_canwait() and MAC Framework and MAC Policy entry points
mac_check_proc_wait(), which control the ability to wait4() specific
processes.  This permits MAC policies to limit information flow from
children that have changed label, although has to be handled carefully
due to common programming expectations regarding the behavior of
wait4().  The cr_seeotheruids() check in p_canwait() is #if 0'd for
this reason.

The mac_stub and mac_test policies are updated to reflect these new
entry points.

Sponsored by:	SPAWAR, SPARTA
Obtained from:	TrustedBSD Project
2005-04-18 13:36:57 +00:00
Robert Watson
030a28b3b5 Introduce new MAC Framework and MAC Policy entry points to control the use
of system calls to manipulate elements of the process credential,
including:

        setuid()                mac_check_proc_setuid()
        seteuid()               mac_check_proc_seteuid()
        setgid()                mac_check_proc_setgid()
        setegid()               mac_check_proc_setegid()
        setgroups()             mac_check_proc_setgroups()
        setreuid()              mac_check_proc_setreuid()
        setregid()              mac_check_proc_setregid()
        setresuid()             mac_check_proc_setresuid()
        setresgid()             mac_check_rpoc_setresgid()

MAC checks are performed before other existing security checks; both
current credential and intended modifications are passed as arguments
to the entry points.  The mac_test and mac_stub policies are updated.

Submitted by:	Samy Al Bahra <samy@kerneled.org>
Obtained from:	TrustedBSD Project
2005-04-16 13:29:15 +00:00
Maxim Sobolev
2322a0a77d Impose the upper limit on signals that are allowed between kernel threads
in set[ug]id program for compatibility with Linux. Linuxthreads uses
4 signals from SIGRTMIN to SIGRTMIN+3.

Pointed out by:		rwatson
2005-03-18 13:33:18 +00:00
Maxim Sobolev
f9cd63d436 Linuxthreads uses not only signal 32 but several signals >= 32.
PR:		kern/72922
Submitted by:	Andriy Gapon <avg@icyb.net.ua>
2005-03-18 11:08:55 +00:00
Maxim Sobolev
4b1783363f In linux emulation layer try to detect attempt to use linux_clone() to
create kernel threads and call rfork(2) with RFTHREAD flag set in this case,
which puts parent and child into the same threading group. As a result
all threads that belong to the same program end up in the same threading
group.

This is similar to what linuxthreads port does, though in this case we don't
have a luxury of having access to the source code and there is no definite
way to differentiate linux_clone() called for threading purposes from other
uses, so that we have to resort to heuristics.

Allow SIGTHR to be delivered between all processes in the same threading
group previously it has been blocked for s[ug]id processes.

This also should improve locking of the same file descriptor from different
threads in programs running under linux compat layer.

PR:			kern/72922
Reported by:		Andriy Gapon <avg@icyb.net.ua>
Idea suggested by:	rwatson
2005-03-03 16:57:55 +00:00
Maxim Sobolev
f460d05699 Backout addition of SIGTHR into the list of signals allowed to be delivered
to the suid/sugid process, since apparently it has security implications.

Suggested by:   rwatson
2005-02-13 17:51:47 +00:00
Maxim Sobolev
1a88a252fd Backout previous change (disabling of security checks for signals delivered
in emulation layers), since it appears to be too broad.

Requested by:   rwatson
2005-02-13 17:37:20 +00:00
Maxim Sobolev
d8ff44b79f Split out kill(2) syscall service routine into user-level and kernel part, the
former is callable from user space and the latter from the kernel one. Make
kernel version take additional argument which tells if the respective call
should check for additional restrictions for sending signals to suid/sugid
applications or not.

Make all emulation layers using non-checked version, since signal numbers in
emulation layers can have different meaning that in native mode and such
protection can cause misbehaviour.

As a result remove LIBTHR from the signals allowed to be delivered to a
suid/sugid application.

Requested (sorta) by:	rwatson
MFC after:	2 weeks
2005-02-13 16:42:08 +00:00
Maxim Sobolev
ac16ff40c5 Add SIGTHR (32) into list of signals permitted to be delivered to the
suid application. The problem is that Linux applications using old Linux
threads (pre-NPTL) use signal 32 (linux SIGRTMIN) for communication between
thread-processes. If such an linux application is installed suid or sgid
and security.bsd.conservative_signals=1 (default), then permission will be
denied to send such a signal and the application will freeze.

I believe the same will be true for native applications that use libthr,
since libthr uses SIGTHR for implementing conditional variables.

PR:		72922
Submitted by:	Andriy Gapon <avg@icyb.net.ua>
MFC after:	2 weeks
2005-02-11 14:02:42 +00:00
Robert Watson
471135a3af Style cleanup: with removal of mutex operations, we can also remove
{}'s from securelevel_gt() and securelevel_ge().

MFC after:	1 week
2005-01-23 21:11:39 +00:00
Robert Watson
0b880542e6 When reading pr_securelevel from a prison, perform a lockless read,
as it's an integer read operation and the resulting slight race is
acceptable.

MFC after:	1 week
2005-01-23 21:01:00 +00:00
Warner Losh
9454b2d864 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
Julian Elischer
99e9dcb817 Remove sched_free_thread() which was only used
in diagnostics. It has outlived its usefulness and has started
causing panics for people who turn on DIAGNOSTIC, in what is otherwise
good code.

MFC after:	2 days
2004-08-31 06:12:13 +00:00
Colin Percival
56f21b9d74 Rename suser_cred()'s PRISON_ROOT flag to SUSER_ALLOWJAIL. This is
somewhat clearer, but more importantly allows for a consistent naming
scheme for suser_cred flags.

The old name is still defined, but will be removed in a few days (unless I
hear any complaints...)

Discussed with:	rwatson, scottl
Requested by:	jhb
2004-07-26 07:24:04 +00:00
Robert Watson
71a057bc73 In setpgid(), since td is passed in as a system call argument, use it
in preference to curthread, which costs slightly more.
2004-07-23 04:26:49 +00:00
Robert Watson
df04411ac4 suser() accepts a thread argument; as suser() dereferences td_ucred, a
thread-local pointer, in practice that thread needs to be curthread.  If
we're running with INVARIANTS, generate a warning if not.  If we have
KDB compiled in, generate a stack trace.  This doesn't fire at all in my
local test environment, but could be irritating if it fires frequently
for someone, so there will be motivation to fix things quickly when it
does.
2004-07-22 17:05:04 +00:00
Colin Percival
24283cc01b Add a SUSER_RUID flag to suser_cred. This flag indicates that we want to
check if the *real* user is the superuser (vs. the normal behaviour, which
checks the effective user).

Reviewed by:	rwatson
2004-07-16 15:57:16 +00:00
Robert Watson
310e7ceb94 Socket MAC labels so_label and so_peerlabel are now protected by
SOCK_LOCK(so):

- Hold socket lock over calls to MAC entry points reading or
  manipulating socket labels.

- Assert socket lock in MAC entry point implementations.

- When externalizing the socket label, first make a thread-local
  copy while holding the socket lock, then release the socket lock
  to externalize to userspace.
2004-06-13 02:50:07 +00:00
Poul-Henning Kamp
1930e303cf Deorbit COMPAT_SUNOS.
We inherited this from the sparc32 port of BSD4.4-Lite1.  We have neither
a sparc32 port nor a SunOS4.x compatibility desire these days.
2004-06-11 11:16:26 +00:00
Warner Losh
7f8a436ff2 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-05 21:03:37 +00:00
Robert Watson
646e29ccac Don't grab Giant in crfree(), since prison_free() no longer requires it.
The uidinfo code appears to be MPSAFE, and is referenced without Giant
elsewhere.  While this grab of Giant was only made in fairly rare
circumstances (actually GC'ing on refcount==0), grabbing Giant here
potentially introduces lock order issues with any locks held by the
caller.  So this probably won't help performance much unless you change
credentials a lot in an application, and leave a lot of file descriptors
and cached credentials around.  However, it simplifies locking down
consumers of the credential interfaces.

Bumped into by:	sam
Appeased:	tjr
2004-01-23 21:07:52 +00:00
Robert Watson
56d9e93207 Rename mac_create_cred() MAC Framework entry point to mac_copy_cred(),
and the mpo_create_cred() MAC policy entry point to
mpo_copy_cred_label().  This is more consistent with similar entry
points for creation and label copying, as mac_create_cred() was
called from crdup() as opposed to during process creation.  For
a number of policies, this removes the requirement for special
handling when copying credential labels, and improves consistency.

Approved by:	re (scottl)
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2003-12-06 21:48:03 +00:00
Robert Watson
64d19c2ea7 Add a sysctl, security.bsd.see_other_gids, similar in semantics
to see_other_uids but with the logical conversion.  This is based
on (but not identical to) the patch submitted by Samy Al Bahra.

Submitted by:	Samy Al Bahra <samy@kerneled.com>
2003-11-17 20:20:53 +00:00
John Baldwin
e07c897e61 Writes to p_flag in __setugid() no longer need Giant. 2003-10-23 21:20:34 +00:00
Robert Watson
62c45ef40a Add a new sysctl, security.bsd.conservative_signals, to disable
special signal-delivery protections for setugid processes.  In the
event that a system is relying on "unusual" signal delivery to
processes that change their credentials, this can be used to work
around application problems.

Also, add SIGALRM to the set of signals permitted to be delivered to
setugid processes by unprivileged subjects.

Reported by:	Joe Greco <jgreco@ns.sol.net>
2003-09-14 07:22:38 +00:00
Don Lewis
857d9c60d0 Extend the mutex pool implementation to permit the creation and use of
multiple mutex pools with different options and sizes.  Mutex pools can
be created with either the default sleep mutexes or with spin mutexes.
A dynamically created mutex pool can now be destroyed if it is no longer
needed.

Create two pools by default, one that matches the existing pool that
uses the MTX_NOWITNESS option that should be used for building higher
level locks, and a new pool with witness checking enabled.

Modify the users of the existing mutex pool to use the appropriate pool
in the new implementation.

Reviewed by:	jhb
2003-07-13 01:22:21 +00:00
Olivier Houchard
a10d5f02c8 In setpgrp(), don't assume a pgrp won't exist if the provided pgid is the same
as the target process' pid, it may exist if the process forked before leaving
the pgrp.
Thix fixes a panic that happens when calling setpgid to make a process
re-enter the pgrp with the same pgid as its pid if the pgrp still exists.
2003-07-04 02:21:28 +00:00
Olivier Houchard
7f3bfd6651 At this point targp will always be NULL, so remove the useless if. 2003-06-25 13:28:32 +00:00
Robert Watson
2bceb0f2b2 Various cr*() calls believed to be MPSAFE, since the uidinfo
code is locked down.
2003-06-15 15:57:42 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
John Baldwin
8bccf7034e The issetugid() function is MPSAFE. 2003-06-09 21:34:19 +00:00
John Baldwin
52c3844c7a Remove Giant from the setuid(), seteuid(), setgid(), setegid(),
setgroups(), setreuid(), setregid(), setresuid(), and setresgid() syscalls
as well as the cred_update_thread() function.
2003-05-01 21:21:42 +00:00
John Baldwin
a70a2b741b Remove Giant from getpgid() and getsid() and tweak the logic to more
closely match that of 4.x.
2003-04-25 20:09:31 +00:00
Warner Losh
a163d034fa Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
Jake Burkholder
3749dff3f9 Remove mtx_lock_giant from functions which are mp-safe. 2003-02-10 04:42:20 +00:00
Alfred Perlstein
44956c9863 Remove M_TRYWAIT/M_WAITOK/M_WAIT. Callers should use 0.
Merge M_NOWAIT/M_DONTWAIT into a single flag M_NOWAIT.
2003-01-21 08:56:16 +00:00
Robert Watson
f9d0d52459 Include file cleanup; mac.h and malloc.h at one point had ordering
relationship requirements, and no longer do.

Reminded by:	bde
2002-08-01 17:47:56 +00:00
Robert Watson
8a1d977d66 Introduce support for Mandatory Access Control and extensible
kernel access control.

Implement inter-process access control entry points for the MAC
framework.  This permits policy modules to augment the decision
making process for process and socket visibility, process debugging,
re-scheduling, and signaling.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-07-31 00:48:24 +00:00
Robert Watson
4024496496 Introduce support for Mandatory Access Control and extensible
kernel access control.

Invoke the necessary MAC entry points to maintain labels on
process credentials.  In particular, invoke entry points for
the initialization and destruction of struct ucred, the copying
of struct ucred, and permit the initial labels to be set for
both process 0 (parent of all kernel processes) and process 1
(parent of all user processes).

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs
2002-07-31 00:39:19 +00:00
Jonathan Mini
aaa1c7715b Revert removal of cred_free_thread(): It is used to ensure that a thread's
credentials are not improperly borrowed when the thread is not current in
the kernel.

Requested by:	jhb, alfred
2002-07-11 02:18:33 +00:00
Alfred Perlstein
7f05b0353a More caddr_t removal, make fo_ioctl take a void * instead of a caddr_t. 2002-06-29 01:50:25 +00:00
Jonathan Mini
01ad8a53db Remove unused diagnostic function cread_free_thread().
Approved by:	alfred
2002-06-24 06:22:00 +00:00
Alfred Perlstein
1419eacb86 Squish the "could sleep with process lock" messages caused by calling
uifind() with a proc lock held.

change_ruid() and change_euid() have been modified to take a uidinfo
structure which will be pre-allocated by callers, they will then
call uihold() on the uidinfo structure so that the caller's logic
is simplified.

This allows one to call uifind() before locking the proc struct and
thereby avoid a potential blocking allocation with the proc lock
held.

This may need revisiting, perhaps keeping a spare uidinfo allocated
per process to handle this situation or re-examining if the proc
lock needs to be held over the entire operation of changing real
or effective user id.

Submitted by: Don Lewis <dl-freebsd@catspoiler.org>
2002-06-19 06:39:25 +00:00
Alfred Perlstein
f2102dadf9 setsugid() touches p->p_flag so assert that the proc is locked. 2002-06-18 22:41:35 +00:00
John Baldwin
f44d9e24fb Change p_can{debug,see,sched,signal}()'s first argument to be a thread
pointer instead of a proc pointer and require the process pointed to
by the second argument to be locked.  We now use the thread ucred reference
for the credential checks in p_can*() as a result.  p_canfoo() should now
no longer need Giant.
2002-05-19 00:14:50 +00:00
Seigo Tanimura
6041fa0a60 As malloc(9) and free(9) are now Giant-free, remove the Giant lock
across malloc(9) and free(9) of a pgrp or a session.
2002-05-03 07:46:59 +00:00
Seigo Tanimura
1c2451c24d Push down Giant for setpgid(), setsid() and aio_daemon(). Giant protects only
malloc(9) and free(9).
2002-04-20 12:02:52 +00:00
John Baldwin
c8b1829d8e - Lock proctree_lock instead of pgrpsess_lock.
- Simplify return logic of setsid() and setpgid().
2002-04-16 17:06:11 +00:00
John Baldwin
07f3485d5e - Change the algorithms of the syscalls to modify process credentials to
allocate a blank cred first, lock the process, perform checks on the
  old process credential, copy the old process credential into the new
  blank credential, modify the new credential, update the process
  credential pointer, unlock the process, and cleanup rather than trying
  to allocate a new credential after performing the checks on the old
  credential.
- Cleanup _setugid() a little bit.
- setlogin() doesn't need Giant thanks to pgrp/session locking and
  td_ucred.
2002-04-13 23:07:05 +00:00