Commit Graph

25 Commits

Author SHA1 Message Date
Mateusz Guzik
3e0178fb94 Check for probes enabled in priv_check_cred before evaluting the error.
Sponsored by:	The FreeBSD Foundation
2018-12-19 23:28:29 +00:00
Mateusz Guzik
cc426dd319 Remove unused argument to priv_check_cred.
Patch mostly generated with cocinnelle:

@@
expression E1,E2;
@@

- priv_check_cred(E1,E2,0)
+ priv_check_cred(E1,E2)

Sponsored by:	The FreeBSD Foundation
2018-12-11 19:32:16 +00:00
Jamie Gritton
b307954481 In hardened systems, where the security.bsd.unprivileged_proc_debug sysctl
node is set, allow setting security.bsd.unprivileged_proc_debug per-jail.
In part, this is needed to create jails in which the Address Sanitizer
(ASAN) fully works as ASAN utilizes libkvm to inspect the virtual address
space. Instead of having to allow unprivileged process debugging for the
entire system, allow setting it on a per-jail basis.

The sysctl node is still security.bsd.unprivileged_proc_debug and the
jail(8) param is allow.unprivileged_proc_debug. The sysctl code is now a
sysctl proc rather than a sysctl int. This allows us to determine setting
the flag for the corresponding jail (or prison0).

As part of the change, the dynamic allow.* API needed to be modified to
take into account pr_allow flags which may now be disabled in prison0.
This prevents conflicts with new pr_allow flags (like that of vmm(4)) that
are added (and removed) dynamically.

Also teach the jail creation KPI to allow differences for certain pr_allow
flags between the parent and child jail. This can happen when unprivileged
process debugging is disabled in the parent prison, but enabled in the
child.

Submitted by:	Shawn Webb <lattera at gmail.com>
Obtained from:	HardenedBSD (45b3625edba0f73b3e3890b1ec3d0d1e95fd47e1, deba0b5078cef0faae43cbdafed3035b16587afc, ab21eeb3b4c72f2500987c96ff603ccf3b6e7de8)
Relnotes:	yes
Sponsored by:	HardenedBSD and G2, Inc
Differential Revision:	https://reviews.freebsd.org/D18319
2018-11-27 17:51:50 +00:00
Jamie Gritton
b19d66fd5a Add a new jail permission, allow.read_msgbuf. When true, jailed processes
can see the dmesg buffer (this is the current behavior).  When false (the
new default), dmesg will be unavailable to jailed users, whether root or
not.

The security.bsd.unprivileged_read_msgbuf sysctl still works as before,
controlling system-wide whether non-root users can see the buffer.

PR:		211580
Submitted by:	bz
Approved by:	re@ (kib@)
MFC after:	3 days
2018-10-17 16:11:43 +00:00
Pedro F. Giffuni
8a36da99de sys/kern: adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:20:12 +00:00
Hans Petter Selasky
af3b2549c4 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
Glen Barber
37a107a407 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
Hans Petter Selasky
3da1cf1e88 Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
Andriy Gapon
d9fae5ab88 dtrace sdt: remove the ugly sname parameter of SDT_PROBE_DEFINE
In its stead use the Solaris / illumos approach of emulating '-' (dash)
in probe names with '__' (two consecutive underscores).

Reviewed by:	markj
MFC after:	3 weeks
2013-11-26 08:46:27 +00:00
Attilio Rao
54366c0bd7 - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00
Jamie Gritton
1e7df84305 Make the comments a little more clear about PRIV_KMEM_*, explicitly
referring to /dev/[k]mem and noting it's about opening the files rather
than actually reading and writing.

Reviewed by:	jmallett
2013-07-06 00:10:52 +00:00
Jamie Gritton
c71e336230 Add new privileges, PRIV_KMEM_READ and PRIV_KMEM_WRITE, used in opening
/dev/kmem and /dev/mem (in addition to traditional file permission checks).
PRIV_KMEM_READ is different from other PRIV_* checks in that it's allowed
by default.

Reviewed by:	kib, mckusick
2013-07-05 21:31:16 +00:00
Pawel Jakub Dawidek
9b9ff7d390 Style nits. 2013-05-19 23:30:24 +00:00
Pawel Jakub Dawidek
9b1040a574 Use SDT_PROBE1() instead of SDT_PROBE(). 2013-05-19 23:29:22 +00:00
Andrey Zonov
5eb0d2838c - Add sysctl to allow unprivileged users to call mlock(2)-family system
calls and turn it on.
- Do not allow to call them inside jail. [1]

Pointed out by:	trasz [1]
Reviewed by:	avg
Approved by:	kib (mentor)
MFC after:	1 week
2012-12-18 07:36:45 +00:00
Rui Paulo
79856499bd Add an extra comment to the SDT probes definition. This allows us to get
use '-' in probe names, matching the probe names in Solaris.[1]

Add userland SDT probes definitions to sys/sdt.h.

Sponsored by:	The FreeBSD Foundation
Discussed with:	rwaston [1]
2010-08-22 11:18:57 +00:00
Robert Watson
bcf11e8d00 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
Robert Watson
73e416e35d Reduce the verbosity of SDT trace points for DTrace by defining several
wrapper macros that allow trace points and arguments to be declared
using a single macro rather than several.  This means a lot less
repetition and vertical space for each trace point.

Use these macros when defining privilege and MAC Framework trace points.

Reviewed by:	jb
MFC after:	1 week
2009-03-03 17:15:05 +00:00
Robert Watson
6efcc2f26a Add static tracing for privilege checking:
priv:kernel:priv_check:priv_ok fires for granted privileges
  priv:kernel:priv_check:priv_errr fires for denied privileges

The first argument is the requested privilege number.  The naming
convention is a little different from the OpenSolaris equivilent
because we can't have '-' in probefunc names, and our privilege
namespace is different.

MFC after:	1 week
2009-02-26 10:56:13 +00:00
Attilio Rao
cecd8edba5 Remove the suser(9) interface from the kernel. It has been replaced from
years by the priv_check(9) interface and just very few places are left.
Note that compatibility stub with older FreeBSD version
(all above the 8 limit though) are left in order to reduce diffs against
old versions. It is responsibility of the maintainers for any module, if
they think it is the case, to axe out such cases.

This patch breaks KPI so __FreeBSD_version will be bumped into a later
commit.

This patch needs to be credited 50-50 with rwatson@ as he found time to
explain me how the priv_check() works in detail and to review patches.

Tested by:      Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
Reviewed by:    rwatson
2008-09-17 15:49:44 +00:00
Robert Watson
b916b56b5a Add __FBSDID() tag.
MFC after:	3 days
Pointed out by:	antoine
2008-03-07 15:27:08 +00:00
Robert Watson
bc6eca2432 Continue kernel privilege cleanup for 7.0: unstaticize suser_enabled and
stop declaring it in systm.h -- it's used only in kern_priv.c and is not
required elsewhere.

Approved by:	re (kensmith)
2007-07-02 14:03:29 +00:00
Robert Watson
7251b7863c Rather than passing SUSER_RUID into priv_check_cred() to specify when
a privilege is checked against the real uid rather than the effective
uid, instead decide which uid to use in priv_check_cred() based on the
privilege passed in.  We use the real uid for PRIV_MAXFILES,
PRIV_MAXPROC, and PRIV_PROC_LIMIT.  Remove the definition of
SUSER_RUID; there are now no flags defined for priv_check_cred().

Obtained from:	TrustedBSD Project
2007-06-16 23:41:43 +00:00
Robert Watson
32f9753cfb Eliminate now-unused SUSER_ALLOWJAIL arguments to priv_check_cred(); in
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.

Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.

We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths.  Do, however, move those prototypes to priv.h.

Reviewed by:	csjp
Obtained from:	TrustedBSD Project
2007-06-12 00:12:01 +00:00
Robert Watson
800c940832 Add a new priv(9) kernel interface for checking the availability of
privilege for threads and credentials.  Unlike the existing suser(9)
interface, priv(9) exposes a named privilege identifier to the privilege
checking code, allowing more complex policies regarding the granting of
privilege to be expressed.  Two interfaces are provided, replacing the
existing suser(9) interface:

suser(td)                 ->   priv_check(td, priv)
suser_cred(cred, flags)   ->   priv_check_cred(cred, priv, flags)

A comprehensive list of currently available kernel privileges may be
found in priv.h.  New privileges are easily added as required, but the
comments on adding privileges found in priv.h and priv(9) should be read
before doing so.

The new privilege interface exposed sufficient information to the
privilege checking routine that it will now be possible for jail to
determine whether a particular privilege is granted in the check routine,
rather than relying on hints from the calling context via the
SUSER_ALLOWJAIL flag.  For now, the flag is maintained, but a new jail
check function, prison_priv_check(), is exposed from kern_jail.c and used
by the privilege check routine to determine if the privilege is permitted
in jail.  As a result, a centralized list of privileges permitted in jail
is now present in kern_jail.c.

The MAC Framework is now also able to instrument privilege checks, both
to deny privileges otherwise granted (mac_priv_check()), and to grant
privileges otherwise denied (mac_priv_grant()), permitting MAC Policy
modules to implement privilege models, as well as control a much broader
range of system behavior in order to constrain processes running with
root privilege.

The suser() and suser_cred() functions remain implemented, now in terms
of priv_check() and the PRIV_ROOT privilege, for use during the transition
and possibly continuing use by third party kernel modules that have not
been updated.  The PRIV_DRIVER privilege exists to allow device drivers to
check privilege without adopting a more specific privilege identifier.

This change does not modify the actual security policy, rather, it
modifies the interface for privilege checks so changes to the security
policy become more feasible.

Sponsored by:		nCircle Network Security, Inc.
Obtained from:		TrustedBSD Project
Discussed on:		arch@
Reviewed (at least in part) by:	mlaier, jmg, pjd, bde, ceri,
			Alex Lyashkov <umka at sevcity dot net>,
			Skip Ford <skip dot ford at verizon dot net>,
			Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:37:19 +00:00