[PATCH v4 0/3] audit: add support for openat2
by Richard Guy Briggs
The openat2(2) syscall was added in v5.6. Add support for openat2 to the
audit syscall classifier and for recording openat2 parameters that cannot
be captured in the syscall parameters of the SYSCALL record.
Supporting userspace code can be found in
https://github.com/rgbriggs/audit-userspace/tree/ghau-openat2
Supporting test case can be found in
https://github.com/linux-audit/audit-testsuite/pull/103
Changelog:
v4:
- change filename include/linux/auditscm.h to auditsc_classmacros.h to avoid socket association
v3:
- re-add commit descriptions that somehow got dropped
- add new file to MAINTAINERS
v2:
- add include/linux/auditscm.h for audit syscall class macros due to syscall redefinition warnings:
arch/x86/ia32/audit.c:3:
./include/linux/audit.h:12,
./include/linux/sched.h:22,
./include/linux/seccomp.h:21,
./arch/x86/include/asm/seccomp.h:5,
./arch/x86/include/asm/unistd.h:20,
./arch/x86/include/generated/uapi/asm/unistd_64.h:4: warning: "__NR_read" redefined #define __NR_read 0
...
./arch/x86/include/generated/uapi/asm/unistd_64.h:338: warning: "__NR_rseq" redefined #define __NR_rseq 334
previous:
arch/x86/ia32/audit.c:2:
./arch/x86/include/generated/uapi/asm/unistd_32.h:7: note: this is the location of the previous definition #define __NR_read 3
...
./arch/x86/include/generated/uapi/asm/unistd_32.h:386: note: this is the location of the previous definition #define __NR_rseq 386
Richard Guy Briggs (3):
audit: replace magic audit syscall class numbers with macros
audit: add support for the openat2 syscall
audit: add OPENAT2 record to list how
MAINTAINERS | 1 +
arch/alpha/kernel/audit.c | 10 ++++++----
arch/ia64/kernel/audit.c | 10 ++++++----
arch/parisc/kernel/audit.c | 10 ++++++----
arch/parisc/kernel/compat_audit.c | 11 ++++++----
arch/powerpc/kernel/audit.c | 12 ++++++-----
arch/powerpc/kernel/compat_audit.c | 13 +++++++-----
arch/s390/kernel/audit.c | 12 ++++++-----
arch/s390/kernel/compat_audit.c | 13 +++++++-----
arch/sparc/kernel/audit.c | 12 ++++++-----
arch/sparc/kernel/compat_audit.c | 13 +++++++-----
arch/x86/ia32/audit.c | 13 +++++++-----
arch/x86/kernel/audit_64.c | 10 ++++++----
fs/open.c | 2 ++
include/linux/audit.h | 11 ++++++++++
include/linux/auditsc_classmacros.h | 24 ++++++++++++++++++++++
include/uapi/linux/audit.h | 1 +
kernel/audit.h | 2 ++
kernel/auditsc.c | 31 +++++++++++++++++++++++------
lib/audit.c | 14 ++++++++-----
lib/compat_audit.c | 15 +++++++++-----
21 files changed, 169 insertions(+), 71 deletions(-)
create mode 100644 include/linux/auditsc_classmacros.h
--
2.27.0
2 years, 8 months
[ANNOUNCE][CFP] Linux Security Summit 2021
by James Morris
==============================================================================
ANNOUNCEMENT AND CALL FOR PARTICIPATION
LINUX SECURITY SUMMIT 2021
27-29 September
Dublin, Ireland
==============================================================================
DESCRIPTION
Linux Security Summit (LSS) is a technical forum for collaboration between
Linux developers, researchers, and end-users. Its primary aim is to foster
community efforts in analyzing and solving Linux security challenges.
The program committee currently seeks proposals for:
* Refereed Presentations:
45 minutes in length.
* Panel Discussion Topics:
45 minutes in length.
* Short Topics:
30 minutes in total, including at least 10 minutes discussion.
* Tutorials
90 minutes in length.
Tutorial sessions should be focused on advanced Linux security defense
topics within areas such as the kernel, compiler, and security-related
libraries. Priority will be given to tutorials created for this conference,
and those where the presenter a leading subject matter expert on the topic.
Topic areas include, but are not limited to:
* Kernel self-protection
* Access control
* Cryptography and key management
* Integrity policy and enforcement
* Hardware Security
* IoT and embedded security
* Virtualization and containers
* System-specific system hardening
* Case studies
* Security tools
* Security UX
* Emerging technologies, threats & techniques
Proposals should be submitted via:
https://events.linuxfoundation.org/linux-security-summit-europe/program/cfp/
** Note that for 2021, the North American and European events are combined into
a single event planned for Dublin, Ireland. **
DATES
* CFP close: June 27
* CFP notifications: July 20
* Schedule announced: July 22
* Event: September 27-29
WHO SHOULD ATTEND
We're seeking a diverse range of attendees and welcome participation by
people involved in Linux security development, operations, and research.
LSS is a unique global event that provides the opportunity to present and
discuss your work or research with key Linux security community members and
maintainers. It's also useful for those who wish to keep up with the latest
in Linux security development and to provide input to the development
process.
WEB SITE
https://events.linuxfoundation.org/linux-security-summit-europe/
TWITTER
For event updates and announcements, follow:
https://twitter.com/LinuxSecSummit
#linuxsecuritysummit
PROGRAM COMMITTEE
The program committee for LSS 2021 is:
* James Morris, Microsoft
* Serge Hallyn, Cisco
* Paul Moore, Cisco
* Stephen Smalley, NSA
* Elena Reshetova, Intel
* John Johansen, Canonical
* Kees Cook, Google
* Casey Schaufler, Intel
* Mimi Zohar, IBM
* David A. Wheeler, Institute for Defense Analyses
The program committee may be contacted as a group via email:
lss-pc () lists.linuxfoundation.org
3 years, 1 month
[RFC PATCH 0/9] Add LSM access controls and auditing to io_uring
by Paul Moore
Earlier this week Kumar Kartikeya Dwivedi posted a patchset switching
io_uring over to the anonymous inode variant that allows for LSM
controls. While nice, the patchset left the actual LSM controls as
an exercise for the reader. The posting can be found using the lore
link below:
https://lore.kernel.org/io-uring/CAHC9VhS=PDxx=MzZnGGNLwo-o5Og-HGZe84=+BB...
As fate would have it, I had been working on something very similar,
in fact the two patches from Kumar mirrored two in my own patchset.
This patchset, while still a bit crude, does include an attempt at
adding the LSM and audit support necessary to properly implement LSM
based access controls for io_uring. I've provided the SELinux
implementation, Casey has been nice enough to provide a Smack patch,
and John is working on an AppArmor patch as I write this. I've
mentioned this work to the other LSM maintainers that I believe might
be affected but I have not heard back from anyone else at this point.
If any of the other LSMs would like to contribute a patch to this
patchset I will happily accept it; I only ask that you post it to the
LSM list and make sure I am on the To/CC line. I think it would be
nice to try and wrap this up as soon as possible for the obvious
reasons.
The individual patches provide an explanation of the changes involved
so I'm not going to repeat that here, but I will caution you that
these patches are still rather crude, perhaps more than a RFC patchset
should be, but it seemed prudent to move this along so I'm posting
these now. Any review that you can provide would be helpful.
Also, any pointers to easy-to-run io_uring tests would be helpful. I
am particularly interested in tests which make use of the personality
option, share urings across process boundaries, and make use of the
sqpoll functionality.
As a point of reference, this patchset is based on v5.13-rc2 and if
you want to follow along via git I'll be making updates to the git
tree/branch below (warning I will be force-pushing on this branch given
the early/rough nature of these patches).
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git
(checkout branch "working-io_uring")
Thanks in advance,
-Paul
---
Casey Schaufler (1):
Smack: Brutalist io_uring support with debug
Paul Moore (8):
audit: prepare audit_context for use in calling contexts beyond syscalls
audit,io_uring,io-wq: add some basic audit support to io_uring
audit: dev/test patch to force io_uring auditing
audit: add filtering for io_uring records
fs: add anon_inode_getfile_secure() similar to anon_inode_getfd_secure()
io_uring: convert io_uring to the secure anon inode interface
lsm,io_uring: add LSM hooks to io_uring
selinux: add support for the io_uring access controls
fs/anon_inodes.c | 29 ++
fs/io-wq.c | 4 +
fs/io_uring.c | 25 +-
include/linux/anon_inodes.h | 4 +
include/linux/audit.h | 17 +
include/linux/lsm_hook_defs.h | 5 +
include/linux/lsm_hooks.h | 13 +
include/linux/security.h | 16 +
include/uapi/linux/audit.h | 4 +-
kernel/audit.h | 7 +-
kernel/auditfilter.c | 4 +-
kernel/auditsc.c | 481 ++++++++++++++++++++++------
security/security.c | 12 +
security/selinux/hooks.c | 67 ++++
security/selinux/include/classmap.h | 2 +
security/smack/smack_lsm.c | 64 ++++
16 files changed, 650 insertions(+), 104 deletions(-)
3 years, 2 months
[GIT PULL] Audit patches for v5.14
by Paul Moore
Hi Linus,
Another merge window, another small audit pull request. Four patches
in total: one is cosmetic, one removes an unnecessary initialization,
one renames some enum values to prevent name collisions, and one
converts list_del()/list_add() to list_move(). None of these are
earth shattering and all pass the audit-testsuite tests while merging
cleanly on top of your tree from earlier today. Please merge these
patches for v5.14.
Thanks,
-Paul
--
The following changes since commit 6efb943b8616ec53a5e444193dccf1af9ad627b5:
Linux 5.13-rc1 (2021-05-09 14:17:44 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit.git
tags/audit-pr-20210629
for you to fetch changes up to 0ecc617858fce305bedcf735eb18a46cb7e9921f:
audit: remove unnecessary 'ret' initialization (2021-06-11 13:21:28 -0400)
----------------------------------------------------------------
audit/stable-5.14 PR 20210629
----------------------------------------------------------------
Austin Kim (1):
audit: remove unnecessary 'ret' initialization
Baokun Li (1):
audit: Use list_move instead of list_del/list_add
Roni Nevalainen (1):
audit: add blank line after variable declarations
Sergey Nazarov (1):
audit: Rename enum audit_state constants to avoid AUDIT_DISABLED
redefinition
Zhen Lei (1):
audit: remove trailing spaces and tabs
include/uapi/linux/audit.h | 4 +--
kernel/audit.h | 10 ++++----
kernel/audit_tree.c | 12 +++------
kernel/auditsc.c | 63 ++++++++++++++++++++++++++++--------------
security/lsm_audit.c | 1 -
5 files changed, 53 insertions(+), 37 deletions(-)
--
paul moore
www.paul-moore.com
3 years, 4 months
AUDIT_ARCH_ and __NR_syscall constants for seccomp filters
by Thomas Weißschuh
Hi everyone,
there does not seem to be a way to access the AUDIT_ARCH_ constant that matches
the currently visible syscall numbers (__NR_...) from the kernel uapi headers.
Background:
I am writing a seccomp BPF filter using the syscall constants to get the
correct syscall numbers for the target architecture.
seccomp_filter.rst tells users to always check the arch values.
But there does not seem a way to get the correct AUDIT_ARCH_ value from the
kernel headers.
Questions:
Is it really necessary to validate the arch value when syscall numbers are
already target-specific?
(If not, should this be added to the docs?)
Would it make sense to expose the audit arch matching the syscall numbers in
the uapi headers?
Link to the actual BPF code:
https://github.com/t-8ch/qmk_firmware/blob/optimize-udev/util/udev/qmk_id...
Thanks,
Thomas
3 years, 4 months
auditd process memory leak
by 宋建昌
My environment：
CPU: Kunpeng 910
arch: aarch64
system: Kylin Linux Advanced Server release V10 (Tercel)
kernel: 4.19.90-23.6.v2101.ky10.aarch64
auditd version:
audit-libs-3.0-5.se.06.ky10.aarch64
audit-3.0-5.se.06.ky10.aarch64
python3-audit-3.0-5.se.06.ky10.aarch64
Auditd process uses an increasing amount of memory
dmesg:
[2358791.243830] audit: type=1305 audit(1624265846.064:245837): audit_pid=0 old=1143857 auid=4294967295
ses=4294967295 res=1
[2358791.256815] audit: type=1131 audit(1624265846.074:245838): pid=1 uid=0 auid=4294967295 ses=4294967295
msg='unit=auditd comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[2358791.328435] audit: type=1305 audit(1624265846.154:245839): audit_enabled=1 old=1 auid=4294967295
ses=4294967295 res=1
[2358791.333944] audit: type=1305 audit(1624265846.154:245840): audit_pid=1275570 old=0 auid=4294967295
ses=4294967295 res=1
audit log:
type=NETFILTER_CFG msg=audit(1624410740.017:257002): table=filter family=2 entries=1821
type=SYSCALL msg=audit(1624410740.017:257002): arch=c00000b7 syscall=208 success=yes exit=0 a0=4 a1=0 a2=40 a3=fffd30290010 items=0 ppid=108096 pid=3965028 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="iptables-restor" exe="/usr/sbin/xtables-legacy-multi" key=(null)
type=PROCTITLE msg=audit(1624410740.017:257002): proctitle=69707461626C65732D726573746F7265002D770035002D2D6E6F666C757368002D2D636F756E74657273
type=NETFILTER_CFG msg=audit(1624410740.037:257003): table=nat family=2 entries=1575
type=SYSCALL msg=audit(1624410740.037:257003): arch=c00000b7 syscall=208 success=yes exit=0 a0=4 a1=0 a2=40 a3=aaadea0c1700 items=0 ppid=108096 pid=3965028 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="iptables-restor" exe="/usr/sbin/xtables-legacy-multi" key=(null)
type=PROCTITLE msg=audit(1624410740.037:257003): proctitle=69707461626C65732D726573746F7265002D770035002D2D6E6F666C757368002D2D636F756E74657273
3 years, 4 months
Internal commands track in AuditD
by Muthamilan Sargunaanandan
Hello SMEs,
I would like to add the Internal commands (example cd , |, > and etc) track
in AuditD.
Can I get the auditd rules to trace the user commands including the
internal commands.
Thanks in advance,
Muthu
3 years, 4 months
Duplicate Rule situation
by warron.french
Does anybody know if I put the following two rules into the same
audit.rules file and reboot the server will we end up with some broken
rules?
-w /etc/audit/ -p a -k watch_audit
-w /etc/audit/rules.d/ -p a -k watch_audit
Will this cause a problem due to duplicate rules?
--------------------------
Warron French
3 years, 4 months
[PATCH v27 00/25] LSM: Module stacking for AppArmor
by Casey Schaufler
This patchset provides the changes required for
the AppArmor security module to stack safely with any other.
v27: Fixes for landlock (patch 02)
Rework the subject audit record generation. This version is
simpler and reflects feedback from Paul Moore. (patch 22)
v26: Rebase to 5.13-rc1
Include the landlock security module.
Accomodate change from security_task_getsecid() to
security_task_getsecid_obj() and security_task_getsecid_subj().
v25: Rebase to 5.12-rc2
Incorporate feedback from v24
- The IMA team suggested improvements to the integrity rule
processing.
v24: Rebase to 5.11-rc1
Incorporate feedback from v23
- Address the IMA team's concerns about "label collisions".
A label collision occurs when there is ambiguity about
which of multiple LSMs is being targeted in the definition
of an integrity check rule. A system with Smack and
AppArmor would be unable to distinguish which LSM is
important to an integrity rule referrencing the label
"unconfined" as that label is meaningful to both.
Provide a boot option to specify which LSM will be used in
IMA rules when multiple LSMs are present. (patch 04)
Pull LSM "slot" identification from later audit patches in
in support of this (patch 03).
- Pick up a few audit events that need to include supplimental
subject context records that had been missed in the
previous version.
v23: Rebase to 5.10-rc4
Incorporate feedback from v22
- Change /proc/*/attr/display to /proc/*/attr/interface_lsm to
make the purpose clearer. (patch 0012)
- Include ABI documentation. (patch 0012, 0022)
- Introduce LSM documentation updates with the patches where
the interfaces are added rather than at the end. (patch 0012, 0022)
Include more maintainers and mail lists in To: and Cc: directives.
v22: Rebase to 5.10-rc1
v21: Rebase to 5.9-rc4
Incorporate feedback from v20
- Further revert UDS SO_PEERSEC to use scaffolding around
the interfaces that use lsmblobs and store only a single
secid. The possibility of multiple security modules
requiring data here is still a future problem.
- Incorporate Richard Guy Briggs' non-syscall auxiliary
records patch (patch 0019-0021) in place of my "supplimental"
records implementation. [I'm not sure I've given proper
attestation. I will correct as appropriate]
v20: Rebase to 5.9-rc1
Change the BPF security module to use the lsmblob data. (patch 0002)
Repair length logic in subject label processing (patch 0015)
Handle -EINVAL from the empty BPF setprocattr hook (patch 0020)
Correct length processing in append_ctx() (patch 0022)
v19: Rebase to 5.8-rc6
Incorporate feedback from v18
- Revert UDS SO_PEERSEC implementation to use lsmblobs
directly, rather than allocating as needed. The correct
treatment of out-of-memory conditions in the later case
is difficult to define. (patch 0005)
- Use a size_t in append_ctx() (patch 0021)
- Fix a memory leak when creating compound contexts. (patch 0021)
Fix build error when CONFIG_SECURITY isn't set (patch 0013)
Fix build error when CONFIG_SECURITY isn't set (patch 0020)
Fix build error when CONFIG_SECURITY isn't set (patch 0021)
v18: Rebase to 5.8-rc3
Incorporate feedback from v17
- Null pointer checking in UDS (patch 0005)
Match changes in IMA code (patch 0012)
Fix the behavior of LSM context supplimental audit
records so that there's always exactly one when it's
appropriate for there to be one. This is a substantial
change that requires extention of the audit_context beyond
syscall events. (patch 0020)
v17: Rebase to 5.7-rc4
v16: Rebase to 5.6
Incorporate feedback from v15 - Thanks Stephen, Mimi and Paul
- Generally improve commit messages WRT scaffolding
- Comment ima_lsm_isset() (patch 0002)
- Some question may remain on IMA warning (patch 0002)
- Mark lsm_slot as __lsm_ro_after_init not __init_data (patch 0002)
- Change name of lsmblob variable in ima_match_rules() (patch 0003)
- Instead of putting a struct lsmblob into the unix_skb_parms
structure put a pointer to an allocated instance. There is
currently only space for 5 u32's in unix_skb_parms and it is
likely to get even tighter. Fortunately, the lifecycle
management of the allocated lsmblob is simple. (patch 0005)
- Dropped Acks due to the above change (patch 0005)
- Improved commentary on secmark labeling scaffolding. (patch 0006)
- Reduced secmark related labeling scaffolding. (patch 0006)
- Replace use of the zeroth entry of an lsmblob in scaffolding
with a function lsmblob_value() to hopefully make it less
obscure. (patch 0006)
- Convert security_secmark_relabel_packet to use lsmblob as
this reduces much of the most contentious scaffolding. (patch 0006)
- Dropped Acks due to the above change (patch 0006)
- Added BUILD_BUG_ON() for CIPSO tag 6. (patch 0018)
- Reworked audit subject information. Instead of adding fields in
the middle of existing records add a new record to the event. When
a separate record is required use subj="?". (patch 0020)
- Dropped Acks due to the above change (patch 0020)
- Reworked audit object information. Instead of adding fields in
the middle of existing records add a new record to the event. When
a separate record is required use obj="?". (patch 0021)
- Dropped Acks due to the above change (patch 0021)
- Enhanced documentation (patch 0022)
- Removed unnecessary error code check in security_getprocattr()
(patch 0021)
v15: Rebase to 5.6-rc1
- Revise IMA data use (patch 0002)
Incorporate feedback from v14
- Fix lockdown module registration naming (patch 0002)
- Revise how /proc/self/attr/context is gathered. (patch 0022)
- Revise access modes on /proc/self/attr/context. (patch 0022)
- Revise documentation on LSM external interfaces. (patch 0022)
v14: Rebase to 5.5-rc5
Incorporate feedback from v13
- Use an array of audit rules (patch 0002)
- Significant change, removed Acks (patch 0002)
- Remove unneeded include (patch 0013)
- Use context.len correctly (patch 0015)
- Reorder code to be more sensible (patch 0016)
- Drop SO_PEERCONTEXT as it's not needed yet (patch 0023)
v13: Rebase to 5.5-rc2
Incorporate feedback from v12
- Print lsmblob size with %z (Patch 0002)
- Convert lockdown LSM initialization. (Patch 0002)
- Restore error check in nft_secmark_compute_secid (Patch 0006)
- Correct blob scaffolding in ima_must_appraise() (Patch 0009)
- Make security_setprocattr() clearer (Patch 0013)
- Use lsm_task_display more widely (Patch 0013)
- Use passed size in lsmcontext_init() (Patch 0014)
- Don't add a smack_release_secctx() hook (Patch 0014)
- Don't print warning in security_release_secctx() (Patch 0014)
- Don't duplicate the label in nfs4_label_init_security() (Patch 0016)
- Remove reviewed-by as code has significant change (Patch 0016)
- Send the entire lsmblob for Tag 6 (Patch 0019)
- Fix description of socket_getpeersec_stream parameters (Patch 0023)
- Retain LSMBLOB_FIRST. What was I thinking? (Patch 0023)
- Add compound context to LSM documentation (Patch 0023)
v12: Rebase to 5.5-rc1
Fixed a couple of incorrect contractions in the text.
v11: Rebase to 5.4-rc6
Incorporate feedback from v10
- Disambiguate reading /proc/.../attr/display by restricting
all use of the interface to the current process.
- Fix a merge error in AppArmor's display attribute check
v10: Ask the security modules if the display can be changed.
v9: There is no version 9
v8: Incorporate feedback from v7
- Minor clean-up in display value management
- refactor "compound" context creation to use a common
append_ctx() function.
v7: Incorporate feedback from v6
- Make setting the display a privileged operation. The
availability of compound contexts reduces the need for
setting the display.
v6: Incorporate feedback from v5
- Add subj_<lsm>= and obj_<lsm>= fields to audit records
- Add /proc/.../attr/context to get the full context in
lsmname\0value\0... format as suggested by Simon McVittie
- Add SO_PEERCONTEXT for getsockopt() to get the full context
in the same format, also suggested by Simon McVittie.
- Add /sys/kernel/security/lsm_display_default to provide
the display default value.
v5: Incorporate feedback from v4
- Initialize the lsmcontext in security_secid_to_secctx()
- Clear the lsmcontext in all security_release_secctx() cases
- Don't use the "display" on strictly internal context
interfaces.
- The SELinux binder hooks check for cases where the context
"display" isn't compatible with SELinux.
v4: Incorporate feedback from v3
- Mark new lsm_<blob>_alloc functions static
- Replace the lsm and slot fields of the security_hook_list
with a pointer to a LSM allocated lsm_id structure. The
LSM identifies if it needs a slot explicitly. Use the
lsm_id rather than make security_add_hooks return the
slot value.
- Validate slot values used in security.c
- Reworked the "display" process attribute handling so that
it works right and doesn't use goofy list processing.
- fix display value check in dentry_init_security
- Replace audit_log of secids with '?' instead of deleting
the audit log
v3: Incorporate feedback from v2
- Make lsmblob parameter and variable names more
meaningful, changing "le" and "l" to "blob".
- Improve consistency of constant naming.
- Do more sanity checking during LSM initialization.
- Be a bit clearer about what is temporary scaffolding.
- Rather than clutter security_getpeersec_dgram with
otherwise unnecessary checks remove the apparmor
stub, which does nothing useful.
Patch 01 moves management of the sock security blob
from the individual modules to the infrastructure.
Patches 02-03 introduce a structure "lsmblob" that will gradually
replace the "secid" as a shorthand for security module information.
At this point lsmblob contains an array of u32 secids, one "slot"
for each of the security modules compiled into the kernel that
used secids. A "slot" is allocated when a security module requests
one.
Patch 04 provides mechanism for the IMA subsystem to identify
explicitly which LSM is subject to IMA policy. This includes
a boot option for specifying the default and an additional option
in IMA rules "lsm=".
Patches 05-13 change LSM interfaces to use the lsmblob instead
of secids. It is important that the lsmblob be a fixed size entity
that does not have to be allocated. Several of the places
where it is used would have performance and/or locking
issues with dynamic allocation.
Patch 14 provides a mechanism for a process to identify which
security module's hooks should be used when displaying or
converting a security context string. A new interface
/proc/self/attr/interface_lsm contains the name of the security
module to show. Reading from this file will present the name of
the module, while writing to it will set the value. Only names
of active security modules are accepted. Internally, the name
is translated to the appropriate "slot" number for the module
which is then stored in the task security blob. Setting the
display requires that all modules using the /proc interfaces
allow the transition. The interface LSM of other processess
can be neither read nor written. All suggested cases for
reading the interface LSM of a different process have race
conditions.
Patch 15 Starts the process of changing how a security
context is represented. Since it is possible for a
security context to have been generated by more than one
security module it is now necessary to note which module
created a security context so that the correct "release"
hook can be called. There are several places where the
module that created a security context cannot be inferred.
This is achieved by introducing a "lsmcontext" structure
which contains the context string, its length and the
"slot" number of the security module that created it.
The security_release_secctx() interface is changed,
replacing the (string,len) pointer pair with a lsmcontext
pointer.
Patches 16-18 convert the security interfaces from
(string,len) pointer pairs to a lsmcontext pointer.
The slot number identifying the creating module is
added by the infrastructure. Where the security context
is stored for extended periods the data type is changed.
The Netlabel code is converted to save lsmblob structures
instead of secids in Patch 19. This is not strictly
necessary as there can only be one security module that
uses Netlabel at this point. Using a lsmblob is much
cleaner, as the interfaces that use the data have all
been converted.
Patch 20 adds checks to the binder hooks which verify
that both ends of a transaction use the same interface LSM.
Patches 21-23 add addition audit records for subject and
object LSM data when there are multiple security modules
with such data. The AUDIT_MAC_TASK_CONTEXTS record is used
in conjuction with a "subj=?" field to identify the subject
data. The AUDIT_MAC_OBJ_CONTEXTS record is used in conjuction
with a "obj=?" field to identify the object data. The
AUDIT_MAC_TASK_CONTEXTS record identifies the security module
with the data: "subj_selinux=xyz_t subj_apparmor=abc". The
AUDIT_MAC_OBJ_CONTEXTS record identifies the security module
with the data: "obj_selinux=xyz_t obj_apparmor=abc". While
AUDIT_MAC_TASK_CONTEXTS records will always contain an entry
for each possible security modules, AUDIT_MAC_OBJ_CONTEXTS
records will only contain entries for security modules for
which the object in question has data.
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=UNKNOWN[1420]
msg=audit(1600880931.832:113)
subj_apparmor==unconfined
subj_smack=_
An example of the MAC_OBJ_CONTEXTS (1421) record is:
type=UNKNOWN[1421]
msg=audit(1601152467.009:1050):
obj_selinux=unconfined_u:object_r:user_home_t:s0
Patch 24 adds a new interface for getting the compound security
contexts, /proc/self/attr/context. An example of the content
of this file is:
selinux\0one_u:one_r:one_t:s0-s0:c0.c1023\0apparmor\0unconfined\0
Finally, with all interference on the AppArmor hooks removed,
Patch 25 removes the exclusive bit from AppArmor. An unnecessary
stub hook was also removed.
The Ubuntu project is using an earlier version of this patchset in
their distribution to enable stacking for containers.
Performance measurements to date have the change within the "noise".
The sockperf and dbench results are on the order of 0.2% to 0.8%
difference, with better performance being as common as worse. The
benchmarks were run with AppArmor and Smack on Ubuntu.
https://github.com/cschaufler/lsm-stacking.git#stack-5.13-rc1-v27
Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com>
Casey Schaufler (25):
LSM: Infrastructure management of the sock security
LSM: Add the lsmblob data structure.
LSM: provide lsm name and id slot mappings
IMA: avoid label collisions with stacked LSMs
LSM: Use lsmblob in security_audit_rule_match
LSM: Use lsmblob in security_kernel_act_as
LSM: Use lsmblob in security_secctx_to_secid
LSM: Use lsmblob in security_secid_to_secctx
LSM: Use lsmblob in security_ipc_getsecid
LSM: Use lsmblob in security_task_getsecid
LSM: Use lsmblob in security_inode_getsecid
LSM: Use lsmblob in security_cred_getsecid
IMA: Change internal interfaces to use lsmblobs
LSM: Specify which LSM to display
LSM: Ensure the correct LSM context releaser
LSM: Use lsmcontext in security_secid_to_secctx
LSM: Use lsmcontext in security_inode_getsecctx
LSM: security_secid_to_secctx in netlink netfilter
NET: Store LSM netlabel data in a lsmblob
LSM: Verify LSM display sanity in binder
audit: add support for non-syscall auxiliary records
Audit: Add record for multiple process LSM attributes
Audit: Add record for multiple object LSM attributes
LSM: Add /proc attr entry for full LSM context
AppArmor: Remove the exclusive flag
Documentation/ABI/testing/ima_policy | 8 +-
Documentation/ABI/testing/procfs-attr-context | 14 +
.../ABI/testing/procfs-attr-lsm_display | 22 +
Documentation/security/lsm.rst | 28 +
drivers/android/binder.c | 26 +-
fs/ceph/xattr.c | 6 +-
fs/nfs/nfs4proc.c | 8 +-
fs/nfsd/nfs4xdr.c | 20 +-
fs/proc/base.c | 2 +
include/linux/audit.h | 35 +-
include/linux/cred.h | 3 +-
include/linux/lsm_hooks.h | 36 +-
include/linux/security.h | 192 +++++-
include/net/netlabel.h | 10 +-
include/net/scm.h | 15 +-
include/net/xfrm.h | 13 +-
include/uapi/linux/audit.h | 2 +
kernel/audit.c | 186 ++++--
kernel/audit.h | 8 +-
kernel/auditfilter.c | 35 +-
kernel/auditsc.c | 145 ++---
kernel/cred.c | 12 +-
net/ipv4/cipso_ipv4.c | 26 +-
net/ipv4/ip_sockglue.c | 12 +-
net/netfilter/nf_conntrack_netlink.c | 24 +-
net/netfilter/nf_conntrack_standalone.c | 11 +-
net/netfilter/nfnetlink_queue.c | 38 +-
net/netfilter/nft_meta.c | 10 +-
net/netfilter/xt_SECMARK.c | 7 +-
net/netlabel/netlabel_kapi.c | 6 +-
net/netlabel/netlabel_unlabeled.c | 103 ++--
net/netlabel/netlabel_unlabeled.h | 2 +-
net/netlabel/netlabel_user.c | 17 +-
net/netlabel/netlabel_user.h | 2 +-
net/xfrm/xfrm_policy.c | 8 +-
net/xfrm/xfrm_state.c | 18 +-
security/apparmor/include/apparmor.h | 3 +-
security/apparmor/include/net.h | 6 +-
security/apparmor/include/procattr.h | 2 +-
security/apparmor/lsm.c | 105 ++--
security/apparmor/procattr.c | 22 +-
security/bpf/hooks.c | 12 +-
security/commoncap.c | 7 +-
security/integrity/ima/ima.h | 10 +-
security/integrity/ima/ima_api.c | 12 +-
security/integrity/ima/ima_appraise.c | 9 +-
security/integrity/ima/ima_main.c | 60 +-
security/integrity/ima/ima_policy.c | 87 ++-
security/integrity/integrity_audit.c | 5 +-
security/landlock/cred.c | 2 +-
security/landlock/fs.c | 2 +-
security/landlock/ptrace.c | 2 +-
security/landlock/setup.c | 5 +
security/landlock/setup.h | 1 +
security/loadpin/loadpin.c | 8 +-
security/lockdown/lockdown.c | 7 +-
security/safesetid/lsm.c | 8 +-
security/security.c | 576 ++++++++++++++++--
security/selinux/hooks.c | 99 +--
security/selinux/include/classmap.h | 2 +-
security/selinux/include/objsec.h | 5 +
security/selinux/include/security.h | 1 +
security/selinux/netlabel.c | 25 +-
security/selinux/ss/services.c | 4 +-
security/smack/smack.h | 6 +
security/smack/smack_access.c | 2 +-
security/smack/smack_lsm.c | 91 +--
security/smack/smack_netfilter.c | 8 +-
security/smack/smackfs.c | 13 +-
security/tomoyo/tomoyo.c | 8 +-
security/yama/yama_lsm.c | 7 +-
71 files changed, 1709 insertions(+), 623 deletions(-)
create mode 100644 Documentation/ABI/testing/procfs-attr-context
create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display
--
2.29.2
3 years, 4 months
Adding support for MAC_TASK_CONTEXTS and MAC_OBJ_CONTEXTS to userspace.
by Casey Schaufler
I'm looking at the audit userspace implications of adding two
new kernel audit records. AUDIT_MAC_TASK_CONTEXTS and
AUDIT_MAC_OBJ_CONTEXTS are used when there are multiple security
modules with a "security context" active on the system. This
design has been discussed here at length. The records will look
like:
AUDIT_MAC_TASK_CONTEXTS
subj_<lsmname>=value
subj_<lsmname>=value
...
Looking at the audit user-space code I see several things
that have me concerned. The first is the use of WITH_APPARMOR.
Going forward what behavior would we want if subj_apparmor=something
shows up on a system that has not got WITH_APPARMOR defined?
The code is inconsistent in that it does not use WITH_SELINUX,
but that's hardly a surprise given its origins. There is also no
WITH_SMACK, but that's unlikely to be an issue since Smack's use
of audit is very much like SELinux's. The question is what to
do about filtering when subj=foo is specified. I suggest that if
any of subj_selinux, subj_smack or subj_something is "foo", it is
a match. But the SELinux components of a label (level, user, ...)
are also available for filtering. If someone wrote a simple Bell &
LaPadula LSM filtering by some of those fields could be useful
there, too.
I would like guidance on whether I ought to go the route of
more extensive use of WITH_APPARMOR (and WITH_SMACK, WITH_MUMBLE)
or take the path of greater generalization. Or, whether I should
treat each case individually and give it my best whack.
Thank you.
3 years, 4 months
