In environments where the preservation of audit events and predictable
usage of system memory are prioritized, admins may use a combination of
--backlog_wait_time and -b options at the risk of degraded performance
resulting from backlog waiting. In some cases, this risk may be
preferred to lost events or unbounded memory usage. Ideally, this risk
can be mitigated by making adjustments when backlog waiting is detected.
However, detection can be difficult using the currently available
metrics. For example, an admin attempting to debug degraded performance
may falsely believe a full backlog indicates backlog waiting. It may
turn out the backlog frequently fills up but drains quickly.
To make it easier to reliably track degraded performance to backlog
waiting, this patch makes the following changes:
Add a new field backlog_wait_time_total to the audit status reply.
Initialize this field to zero. Add to this field the total time spent
by the current task on scheduled timeouts while the backlog limit is
exceeded. Reset field to zero upon request via AUDIT_SET.
Tested on Ubuntu 18.04 using complementary changes to the
audit-userspace and audit-testsuite:
- https://github.com/linux-audit/audit-userspace/pull/134
- https://github.com/linux-audit/audit-testsuite/pull/97
Signed-off-by: Max Englander <max.englander@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Allow for audit messages to be emitted upon BPF program load and
unload for having a timeline of events. The load itself is in
syscall context, so additional info about the process initiating
the BPF prog creation can be logged and later directly correlated
to the unload event.
The only info really needed from BPF side is the globally unique
prog ID where then audit user space tooling can query / dump all
info needed about the specific BPF program right upon load event
and enrich the record, thus these changes needed here can be kept
small and non-intrusive to the core.
Raw example output:
# auditctl -D
# auditctl -a always,exit -F arch=x86_64 -S bpf
# ausearch --start recent -m 1334
...
----
time->Wed Nov 27 16:04:13 2019
type=PROCTITLE msg=audit(1574867053.120:84664): proctitle="./bpf"
type=SYSCALL msg=audit(1574867053.120:84664): arch=c000003e syscall=321 \
success=yes exit=3 a0=5 a1=7ffea484fbe0 a2=70 a3=0 items=0 ppid=7477 \
pid=12698 auid=1001 uid=1001 gid=1001 euid=1001 suid=1001 fsuid=1001 \
egid=1001 sgid=1001 fsgid=1001 tty=pts2 ses=4 comm="bpf" \
exe="/home/jolsa/auditd/audit-testsuite/tests/bpf/bpf" \
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1334] msg=audit(1574867053.120:84664): prog-id=76 op=LOAD
----
time->Wed Nov 27 16:04:13 2019
type=UNKNOWN[1334] msg=audit(1574867053.120:84665): prog-id=76 op=UNLOAD
...
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/bpf/20191206214934.11319-1-jolsa@kernel.org
This renames the very specific audit_log_link_denied() to
audit_log_path_denied() and adds the AUDIT_* type as an argument. This
allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
report the fifo/regular file creation restrictions that were introduced
in commit 30aba6656f ("namei: allow restricted O_CREAT of FIFOs and
regular files").
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Provide a method to filter out sockaddr and bind calls by network
address family.
Existing SOCKADDR records are listed for any network activity.
Implement the AUDIT_SADDR_FAM field selector to be able to classify or
limit records to specific network address families, such as AF_INET or
AF_INET6.
An example of a network record that is unlikely to be useful and flood
the logs:
type=SOCKADDR msg=audit(07/27/2017 12:18:27.019:845) : saddr={ fam=local
path=/var/run/nscd/socket }
type=SYSCALL msg=audit(07/27/2017 12:18:27.019:845) : arch=x86_64
syscall=connect success=no exit=ENOENT(No such file or directory) a0=0x3
a1=0x7fff229c4980 a2=0x6e a3=0x6 items=1 ppid=3301 pid=6145 auid=sgrubb
uid=sgrubb gid=sgrubb euid=sgrubb suid=sgrubb fsuid=sgrubb egid=sgrubb
sgid=sgrubb fsgid=sgrubb tty=pts3 ses=4 comm=bash exe=/usr/bin/bash
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
key=network-test
Please see the audit-testsuite PR at
https://github.com/linux-audit/audit-testsuite/pull/87
Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/64
Please see the github issue for the accompanying userspace support
https://github.com/linux-audit/audit-userspace/issues/93
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in auditfilter.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Emit an audit record every time selected NTP parameters are modified
from userspace (via adjtimex(2) or clock_adjtime(2)). These parameters
may be used to indirectly change system clock, and thus their
modifications should be audited.
Such events will now generate records of type AUDIT_TIME_ADJNTPVAL
containing the following fields:
- op -- which value was adjusted:
- offset -- corresponding to the time_offset variable
- freq -- corresponding to the time_freq variable
- status -- corresponding to the time_status variable
- adjust -- corresponding to the time_adjust variable
- tick -- corresponding to the tick_usec variable
- tai -- corresponding to the timekeeping's TAI offset
- old -- the old value
- new -- the new value
Example records:
type=TIME_ADJNTPVAL msg=audit(1530616044.507:7): op=status old=64 new=8256
type=TIME_ADJNTPVAL msg=audit(1530616044.511:11): op=freq old=0 new=49180377088000
The records of this type will be associated with the corresponding
syscall records.
An overview of parameter changes that can be done via do_adjtimex()
(based on information from Miroslav Lichvar) and whether they are
audited:
__timekeeping_set_tai_offset() -- sets the offset from the
International Atomic Time
(AUDITED)
NTP variables:
time_offset -- can adjust the clock by up to 0.5 seconds per call
and also speed it up or slow down by up to about
0.05% (43 seconds per day) (AUDITED)
time_freq -- can speed up or slow down by up to about 0.05%
(AUDITED)
time_status -- can insert/delete leap seconds and it also enables/
disables synchronization of the hardware real-time
clock (AUDITED)
time_maxerror, time_esterror -- change error estimates used to
inform userspace applications
(NOT AUDITED)
time_constant -- controls the speed of the clock adjustments that
are made when time_offset is set (NOT AUDITED)
time_adjust -- can temporarily speed up or slow down the clock by up
to 0.05% (AUDITED)
tick_usec -- a more extreme version of time_freq; can speed up or
slow down the clock by up to 10% (AUDITED)
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Emit an audit record whenever the system clock is changed (i.e. shifted
by a non-zero offset) by a syscall from userspace. The syscalls than can
(at the time of writing) trigger such record are:
- settimeofday(2), stime(2), clock_settime(2) -- via
do_settimeofday64()
- adjtimex(2), clock_adjtime(2) -- via do_adjtimex()
The new records have type AUDIT_TIME_INJOFFSET and contain the following
fields:
- sec -- the 'seconds' part of the offset
- nsec -- the 'nanoseconds' part of the offset
Example record (time was shifted backwards by ~15.875 seconds):
type=TIME_INJOFFSET msg=audit(1530616049.652:13): sec=-16 nsec=124887145
The records of this type will be associated with the corresponding
syscall records.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
[PM: fixed a line width problem in __audit_tk_injoffset()]
Signed-off-by: Paul Moore <paul@paul-moore.com>
syscall_get_arch() is required to be implemented on all architectures
in addition to already implemented syscall_get_nr(),
syscall_get_arguments(), syscall_get_error(), and
syscall_get_return_value() functions in order to extend the generic
ptrace API with PTRACE_GET_SYSCALL_INFO request.
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: Elvira Khabirova <lineprinter@altlinux.org>
Cc: Eugene Syromyatnikov <esyr@redhat.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: linux-audit@redhat.com
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This is sort of a mix between a new feature and a bug fix. I've managed
to screw up merging this patch set a handful of times but I think it's
OK this time around. The main new feature here is audit support for
RISC-V, with some fixes to audit-related bugs that cropped up along the
way:
* The addition of NR_syscalls into unistd.h, which is necessary for
CONFIG_FTRACE_SYSCALLS.
* The definition of CREATE_TRACE_POINTS so
__tracepoint_sys_{enter,exit} get defined.
* A fix for trace_sys_exit() so we can enable
CONFIG_HAVE_SYSCALL_TRACEPOINTS.
On RISC-V (riscv) audit is supported through generic lib/audit.c.
The patch adds required arch specific definitions.
Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
syscall_get_arch() is required to be implemented on all architectures
in order to extend the generic ptrace API with PTRACE_GET_SYSCALL_INFO
request.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Pull integrity updates from James Morris:
"This adds support for EVM signatures based on larger digests, contains
a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the
IMA policy rules from the IMA-audit messages, addresses two deadlocks
due to either loading or searching for crypto algorithms, and cleans
up the audit messages"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
EVM: fix return value check in evm_write_xattrs()
integrity: prevent deadlock during digsig verification.
evm: Allow non-SHA1 digital signatures
evm: Don't deadlock if a crypto algorithm is unavailable
integrity: silence warning when CONFIG_SECURITYFS is not enabled
ima: Differentiate auditing policy rules from "audit" actions
ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
ima: Use audit_log_format() rather than audit_log_string()
ima: Call audit_log_string() rather than logging it untrusted
The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action. This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.
Since we defined a new message type we can now also pass the
audit_context and get an associated SYSCALL record. This now produces
the following records when parsing IMA policy's rules:
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
func=MMAP_CHECK mask=MAY_EXEC res=1
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
func=FILE_CHECK mask=MAY_READ res=1
type=SYSCALL msg=audit(1527888965.738:320): arch=c000003e syscall=1 \
success=yes exit=17 a0=1 a1=55bcfcca9030 a2=11 a3=7fcc1b55fb38 \
items=0 ppid=1567 pid=1601 auid=0 uid=0 gid=0 euid=0 suid=0 \
fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="echo" \
exe="/usr/bin/echo" \
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
The AUDIT_FILTER_TYPE name is vague and misleading due to not describing
where or when the filter is applied and obsolete due to its available
filter fields having been expanded.
Userspace has already renamed it from AUDIT_FILTER_TYPE to
AUDIT_FILTER_EXCLUDE without checking if it already exists. The
userspace maintainer assures that as long as it is set to the same value
it will not be a problem since the userspace code does not treat
compiler warnings as errors. If this policy changes then checks if it
already exists can be added at the same time.
See: https://github.com/linux-audit/audit-kernel/issues/89
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull integrity updates from James Morris:
"From Mimi:
- add run time support for specifying additional security xattrs
included in the security.evm HMAC/signature
- some code clean up and bug fixes"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
EVM: unlock on error path in evm_read_xattrs()
EVM: prevent array underflow in evm_write_xattrs()
EVM: Fix null dereference on xattr when xattr fails to allocate
EVM: fix memory leak of temporary buffer 'temp'
IMA: use list_splice_tail_init_rcu() instead of its open coded variant
ima: use match_string() helper
ima: fix updating the ima_appraise flag
ima: based on policy verify firmware signatures (pre-allocated buffer)
ima: define a new policy condition based on the filesystem name
EVM: Allow runtime modification of the set of verified xattrs
EVM: turn evm_config_xattrnames into a list
integrity: Add an integrity directory in securityfs
ima: Remove unused variable ima_initialized
ima: Unify logging
ima: Reflect correct permissions for policy
Sites may wish to provide additional metadata alongside files in order
to make more fine-grained security decisions[1]. The security of this is
enhanced if this metadata is protected, something that EVM makes
possible. However, the kernel cannot know about the set of extended
attributes that local admins may wish to protect, and hardcoding this
policy in the kernel makes it difficult to change over time and less
convenient for distributions to enable.
This patch adds a new /sys/kernel/security/integrity/evm/evm_xattrs node,
which can be read to obtain the current set of EVM-protected extended
attributes or written to in order to add new entries. Extending this list
will not change the validity of any existing signatures provided that the
file in question does not have any of the additional extended attributes -
missing xattrs are skipped when calculating the EVM hash.
[1] For instance, a package manager could install information about the
package uploader in an additional extended attribute. Local LSM policy
could then be associated with that extended attribute in order to
restrict the privileges available to packages from less trusted
uploaders.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Use a macro, "AUDIT_SID_UNSET", to replace each instance of
initialization and comparison to an audit session ID.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
