[PATCH] audit: always enable syscall auditing when supported and audit is enabled
by Paul Moore
To the best of our knowledge, everyone who enables audit at compile
time also enables syscall auditing; this patch simplifies the Kconfig
menus by removing the option to disable syscall auditing when audit
is selected and the target arch supports it.
Signed-off-by: Paul Moore <pmoore(a)redhat.com>
---
init/Kconfig | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/init/Kconfig b/init/Kconfig
index c24b6f7..d4663b1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -299,20 +299,15 @@ config AUDIT
help
Enable auditing infrastructure that can be used with another
kernel subsystem, such as SELinux (which requires this for
- logging of avc messages output). Does not do system-call
- auditing without CONFIG_AUDITSYSCALL.
+ logging of avc messages output). System call auditing is included
+ on architectures which support it.
config HAVE_ARCH_AUDITSYSCALL
bool
config AUDITSYSCALL
- bool "Enable system-call auditing support"
+ def_bool y
depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
- default y if SECURITY_SELINUX
- help
- Enable low-overhead system-call auditing infrastructure that
- can be used independently or with another kernel subsystem,
- such as SELinux.
config AUDIT_WATCH
def_bool y
5 years, 10 months
[PATCH ghak90 (was ghak32) V4 00/10] audit: implement container identifier
by Richard Guy Briggs
Implement kernel audit container identifier.
This patchset is a fourth based on the proposal document (V3)
posted:
https://www.redhat.com/archives/linux-audit/2018-January/msg00014.html
The first patch is the last patch from ghak81 that is included here as a
convenience.
The second patch implements the proc fs write to set the audit container
identifier of a process, emitting an AUDIT_CONTAINER_OP record to announce the
registration of that audit container identifier on that process. This patch
requires userspace support for record acceptance and proper type
display.
The third implements the auxiliary record AUDIT_CONTAINER if an
audit container identifier is identifiable with an event. This patch
requires userspace support for proper type display.
The 4th adds signal and ptrace support.
The 5th creates a local audit context to be able to bind a standalone
record with a locally created auxiliary record.
The 6th patch adds audit container identifier records to the tty
standalone record.
The 7th adds audit container identifier filtering to the exit,
exclude and user lists. This patch adds the AUDIT_CONTID field and
requires auditctl userspace support for the --contid option.
The 8th adds network namespace audit container identifier labelling
based on member tasks' audit container identifier labels.
The 9th adds audit container identifier support to standalone netfilter
records that don't have a task context and lists each container to which
that net namespace belongs.
The 10th implements reading the audit container identifier from the proc
filesystem for debugging. This patch isn't planned for upstream
inclusion.
Example: Set an audit container identifier of 123456 to the "sleep" task:
sleep 2&
child=$!
echo 123456 > /proc/$child/audit_containerid; echo $?
ausearch -ts recent -m container
echo child:$child contid:$( cat /proc/$child/audit_containerid)
This should produce a record such as:
type=CONTAINER_OP msg=audit(2018-06-06 12:39:29.636:26949) : op=set opid=2209 old-contid=18446744073709551615 contid=123456 pid=628 auid=root uid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=bash exe=/usr/bin/bash res=yes
Example: Set a filter on an audit container identifier 123459 on /tmp/tmpcontainerid:
contid=123459
key=tmpcontainerid
auditctl -a exit,always -F dir=/tmp -F perm=wa -F contid=$contid -F key=$key
perl -e "sleep 1; open(my \$tmpfile, '>', \"/tmp/$key\"); close(\$tmpfile);" &
child=$!
echo $contid > /proc/$child/audit_containerid
sleep 2
ausearch -i -ts recent -k $key
auditctl -d exit,always -F dir=/tmp -F perm=wa -F contid=$contid -F key=$key
rm -f /tmp/$key
This should produce an event such as:
type=CONTAINER msg=audit(2018-06-06 12:46:31.707:26953) : op=task contid=123459
type=PROCTITLE msg=audit(2018-06-06 12:46:31.707:26953) : proctitle=perl -e sleep 1; open(my $tmpfile, '>', "/tmp/tmpcontainerid"); close($tmpfile);
type=PATH msg=audit(2018-06-06 12:46:31.707:26953) : item=1 name=/tmp/tmpcontainerid inode=25656 dev=00:26 mode=file,644 ouid=root ogid=root rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=CREATE cap_fp=none cap_fi=none cap_fe=0 cap_fver=0
type=PATH msg=audit(2018-06-06 12:46:31.707:26953) : item=0 name=/tmp/ inode=8985 dev=00:26 mode=dir,sticky,777 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:tmp_t:s0 nametype=PARENT cap_fp=none cap_fi=none cap_fe=0 cap_fver=0
type=CWD msg=audit(2018-06-06 12:46:31.707:26953) : cwd=/root
type=SYSCALL msg=audit(2018-06-06 12:46:31.707:26953) : arch=x86_64 syscall=openat success=yes exit=3 a0=0xffffffffffffff9c a1=0x5621f2b81900 a2=O_WRONLY|O_CREAT|O_TRUNC a3=0x1b6 items=2 ppid=628 pid=2232 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=tmpcontainerid
Includes: https://github.com/linux-audit/audit-kernel/issues/81
See: https://github.com/linux-audit/audit-kernel/issues/90
See: https://github.com/linux-audit/audit-userspace/issues/40
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
Changelog:
v4
- preface set with ghak81:"collect audit task parameters"
- add shallyn and sgrubb acks
- rename feature bitmap macro
- rename cid_valid() to audit_contid_valid()
- rename AUDIT_CONTAINER_ID to AUDIT_CONTAINER_OP
- delete audit_get_contid_list() from headers
- move work into inner if, delete "found"
- change netns contid list function names
- move exports for audit_log_contid audit_alloc_local audit_free_context to non-syscall patch
- list contids CSV
- pass in gfp flags to audit_alloc_local() (fix audit_alloc_context callers)
- use "local" in lieu of abusing in_syscall for auditsc_get_stamp()
- read_lock(&tasklist_lock) around children and thread check
- task_lock(tsk) should be taken before first check of tsk->audit
- add spin lock to contid list in aunet
- restrict /proc read to CAP_AUDIT_CONTROL
- remove set again prohibition and inherited flag
- delete contidion spelling fix from patchset, send to netdev/linux-wireless
v3
- switched from containerid in task_struct to audit_task_info (depends on ghak81)
- drop INVALID_CID in favour of only AUDIT_CID_UNSET
- check for !audit_task_info, throw -ENOPROTOOPT on set
- changed -EPERM to -EEXIST for parent check
- return AUDIT_CID_UNSET if !audit_enabled
- squash child/thread check patch into AUDIT_CONTAINER_ID patch
- changed -EPERM to -EBUSY for child check
- separate child and thread checks, use -EALREADY for latter
- move addition of op= from ptrace/signal patch to AUDIT_CONTAINER patch
- fix && to || bashism in ptrace/signal patch
- uninline and export function for audit_free_context()
- drop CONFIG_CHANGE, FEATURE_CHANGE, ANOM_ABEND, ANOM_SECCOMP patches
- move audit_enabled check (xt_AUDIT)
- switched from containerid list in struct net to net_generic's struct audit_net
- move containerid list iteration into audit (xt_AUDIT)
- create function to move namespace switch into audit
- switched /proc/PID/ entry from containerid to audit_containerid
- call kzalloc with GFP_ATOMIC on in_atomic() in audit_alloc_context()
- call kzalloc with GFP_ATOMIC on in_atomic() in audit_log_container_info()
- use xt_net(par) instead of sock_net(skb->sk) to get net
- switched record and field names: initial CONTAINER_ID, aux CONTAINER, field CONTID
- allow to set own contid
- open code audit_set_containerid
- add contid inherited flag
- ccontainerid and pcontainerid eliminated due to inherited flag
- change name of container list funcitons
- rename containerid to contid
- convert initial container record to syscall aux
- fix spelling mistake of contidion in net/rfkill/core.c to avoid contid name collision
v2
- add check for children and threads
- add network namespace container identifier list
- add NETFILTER_PKT audit container identifier logging
- patch description and documentation clean-up and example
- reap unused ppid
Richard Guy Briggs (10):
audit: collect audit task parameters
audit: add container id
audit: log container info of syscalls
audit: add containerid support for ptrace and signals
audit: add support for non-syscall auxiliary records
audit: add containerid support for tty_audit
audit: add containerid filtering
audit: add support for containerid to network namespaces
audit: NETFILTER_PKT: record each container ID associated with a netNS
debug audit: read container ID of a process
drivers/tty/tty_audit.c | 5 +-
fs/proc/base.c | 56 ++++++++++++++
include/linux/audit.h | 95 ++++++++++++++++++++---
include/linux/sched.h | 5 +-
include/uapi/linux/audit.h | 8 +-
init/init_task.c | 3 +-
init/main.c | 2 +
kernel/audit.c | 137 +++++++++++++++++++++++++++++++++
kernel/audit.h | 4 +
kernel/auditfilter.c | 47 ++++++++++++
kernel/auditsc.c | 183 ++++++++++++++++++++++++++++++++++++++++-----
kernel/fork.c | 4 +-
kernel/nsproxy.c | 4 +
net/netfilter/xt_AUDIT.c | 12 ++-
14 files changed, 526 insertions(+), 39 deletions(-)
--
1.8.3.1
5 years, 11 months
[PATCH ghak95] audit: Do not log full CWD path on empty relative paths
by Ondrej Mosnacek
When a relative path has just a single component and we want to emit a
nametype=PARENT record, the current implementation just reports the full
CWD path (which is alrady available in the audit context).
This is wrong for three reasons:
1. Wasting log space for redundant data (CWD path is already in the CWD
record).
2. Inconsistency with other PATH records (if a relative PARENT directory
path contains at least one component, only the verbatim relative path
is logged).
3. In some syscalls (e.g. openat(2)) the relative path may not even be
relative to the CWD, but to another directory specified as a file
descriptor. In that case the logged path is simply plain wrong.
This patch modifies this behavior to simply report "." in the
aforementioned case, which is equivalent to an "empty" directory path
and can be concatenated with the actual base directory path (CWD or
dirfd from openat(2)-like syscall) once support for its logging is added
later. In the meantime, defaulting to CWD as base directory on relative
paths (as already done by the userspace tools) will be enough to achieve
results equivalent to the current behavior.
See: https://github.com/linux-audit/audit-kernel/issues/95
Fixes: 9c937dcc7102 ("[PATCH] log more info for directory entry change events")
Signed-off-by: Ondrej Mosnacek <omosnace(a)redhat.com>
---
kernel/audit.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/kernel/audit.c b/kernel/audit.c
index 2a8058764aa6..4f18bd48eb4b 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2127,28 +2127,27 @@ void audit_log_name(struct audit_context *context, struct audit_names *n,
audit_log_format(ab, "item=%d", record_num);
+ audit_log_format(ab, " name=");
if (path)
- audit_log_d_path(ab, " name=", path);
+ audit_log_d_path(ab, NULL, path);
else if (n->name) {
switch (n->name_len) {
case AUDIT_NAME_FULL:
/* log the full path */
- audit_log_format(ab, " name=");
audit_log_untrustedstring(ab, n->name->name);
break;
case 0:
/* name was specified as a relative path and the
* directory component is the cwd */
- audit_log_d_path(ab, " name=", &context->pwd);
+ audit_log_untrustedstring(ab, ".");
break;
default:
/* log the name's directory component */
- audit_log_format(ab, " name=");
audit_log_n_untrustedstring(ab, n->name->name,
n->name_len);
}
} else
- audit_log_format(ab, " name=(null)");
+ audit_log_format(ab, "(null)");
if (n->ino != AUDIT_INO_UNSET)
audit_log_format(ab, " inode=%lu"
--
2.17.1
6 years
[RFC PATCH 0/3] simplify struct audit_krule reveals bug
by Richard Guy Briggs
In the process of trying to track down a potential bug altering the
registered arch for a syscall rule, a simplification of struct
audit_krule that removes a seemingly unnecessary member has revealed a
surprising NULL pointer dereference.
The struct audit_field *arch_f member should not be necessary since it
is the first field present if it is present at all, and is only
necessary for syscall rules, so iterating over the fields to find it is
simple and only happens when adding or deleting a rule. Shrinking the
struct audit_krule seemed to be a good idea, but appears to have openned
a can of worms. The first patch triggered this OOPS:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000009
IP: audit_match_signal+0x42/0x120
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
Modules linked in: sunrpc 8139too i2c_piix4 pcspkr virtio_balloon 8139cp i2c_core mii sch_fq_codel floppy serio_raw ata_generic pata_acpi
CPU: 1 PID: 325 Comm: auditctl Not tainted 4.15.0-bz1462178-arch-changed+ #636
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:audit_match_signal+0x42/0x120
RSP: 0018:ffffc900003dfc08 EFLAGS: 00010202
RAX: 0000000000000003 RBX: ffff880036588000 RCX: 0000000000000003
RDX: ffff88003c7f02e0 RSI: ffff88003c7f02a0 RDI: ffff880036588000
RBP: ffff88003671de00 R08: 0000000000000001 R09: 0000000000000000
R10: ffff880036a0b190 R11: 0000000000000000 R12: 0000000000000000
R13: ffff880036588178 R14: ffff880036588000 R15: ffffffff8247f880
FS: 00007fa53c6d9740(0000) GS:ffff88003e400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000009 CR3: 00000000347ba000 CR4: 00000000000006e0
Call Trace:
audit_rule_change+0xb32/0xce0
audit_receive_msg+0x163/0x1090
? netlink_deliver_tap+0x90/0x350
? kvm_sched_clock_read+0x5/0x10
? sched_clock+0x5/0x10
audit_receive+0x4d/0xa0
netlink_unicast+0x195/0x250
netlink_sendmsg+0x2fe/0x3f0
sock_sendmsg+0x32/0x60
SYSC_sendto+0xda/0x140
? syscall_trace_enter+0x2dc/0x400
? return_from_SYSCALL_64+0x10/0x75
do_syscall_64+0x83/0x360
entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7fa53bbb1607
RSP: 002b:00007fff33f48c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000444 RCX: 00007fa53bbb1607
RDX: 0000000000000444 RSI: 00007fff33f48cb0 RDI: 0000000000000003
RBP: 0000000000000431 R08: 00007fff33f48c9c R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fff33f48cb0 R14: 00007fff33f48c9c R15: 00000000000003f3
Code: 01 00 00 83 3e 0b 0f 84 ef 00 00 00 31 c0 eb 0f 48 63 d0 48 c1 e2 05 48 01 f2 83 3a 0b 74 7d 83 c0 01 39 c8 75 ea 4d 85 c0 74 79 <41> 8b 78 08 e8 25 ff ed ff 85 c0 74 31 83 f8 01 75 58 48 8b 0d
RIP: audit_match_signal+0x42/0x120 RSP: ffffc900003dfc08
CR2: 0000000000000009
The second patch surprisingly fixes the OOPS.
Adding debug output, the OOPS is consistently happenning in the 7th STIG rule
that includes an arch parameter, but the value that causes the OOPS
dereferences, copies and prints out fine:
-a always,exit -F arch=b32 -S adjtimex,settimeofday,stime -F key=time-change
ams_: i=0 f=00000000e5612893 type=11 op=0 val=40000003 key="time-change"
-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=time-change
ams_: i=0 f=00000000cf222aca type=11 op=0 val=c000003e key="time-change"
-a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
ams_: i=0 f=00000000ad39bfc6 type=11 op=0 val=40000003 key="time-change"
-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
ams_: i=0 f=00000000c9f83209 type=11 op=0 val=c000003e key="time-change"
-a always,exit -F arch=b32 -S sethostname,setdomainname -F key=system-locale
ams_: i=0 f=000000005a19d216 type=11 op=0 val=40000003 key="system-locale"
-a always,exit -F arch=b64 -S sethostname,setdomainname -F key=system-locale
ams_: i=0 f=000000003280e47a type=11 op=0 val=c000003e key="system-locale"
OOPS
-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=4294967295 -F key=perm_mod
ams_: i=0 f=000000008368170a type=11 op=0 val=40000003 key="perm_mod"
I'd let sleeping dogs lie, but I haven't tracked down the source of the
original rule that changes arch between addition and listing (nor reproduced it
yet since I don't have access to that HW arch), and it seems to reveal
potentially another bug.
Help! Any observations or hints?
Richard Guy Briggs (3):
audit: remove arch_f pointer from struct audit_krule
fixup! audit: remove arch_f pointer from struct audit_krule
debug! audit: remove arch_f pointer from struct audit_krule
include/linux/audit.h | 1 -
kernel/auditfilter.c | 18 +++++++++++++-----
2 files changed, 13 insertions(+), 6 deletions(-)
--
1.8.3.1
6 years
[PATCH ghak59 V2 0/6] audit: config_change normalizations and event record gathering
by Richard Guy Briggs
Make a number of changes to normalize CONFIG_CHANGE records by adding
missing op= fields, providing more information in existing op fields and
connecting all records to existing audit events.
The user record patch is included but is *optional* since there is doubt
that we want to disconnect the records from a single event.
Since tree purge records are processed after the EOE record is produced,
the order of operation of the EOE record and the purge will have to be
reversed so that the purge records can be included in the event.
For reference, here are the calling methods and function tree for all
CONFIG_CHANGE events:
- audit_log_config_change() "op=set"
- AUDIT_SET:AUDIT_STATUS_PID
- AUDIT_SET:AUDIT_STATUS_LOST
- audit_do_config_change()
- AUDIT_SET:AUDIT_STATUS_FAILURE
- AUDIT_SET:AUDIT_STATUS_ENABLED
- AUDIT_SET:AUDIT_STATUS_RATE_LIMIT
- AUDIT_SET:AUDIT_STATUS_BACKLOG_LIMIT
- AUDIT_SET:AUDIT_STATUS_BACKLOG_WAIT_TIME
- audit_log_common_recv_msg()
- AUDIT_*USER* events (not CONFIG_CHANGE like all the rest)
- AUDIT_LOCKED "op=%s_rule"(add/remove)
- AUDIT_TRIM "op=trim"
- AUDIT_MAKE_EQUIV: "op=make_equiv"
- AUDIT_TTY_SET: "op=tty_set"
- audit_log_rule_change()
- AUDIT_ADD_RULE -F dir=:
- AUDIT_DEL_RULE -F dir=:
- audit_mark_log_rule_change()
- audit_autoremove_mark_rule() "op=autoremove_rule(mark)"
- audit_mark_handle_event()
- audit_mark_fsnotify_ops.handle_event
- audit_tree_log_remove_rule() "op=remove_rule(tree:%s)" from kill_rules()
- from trim_marked()
- AUDIT_TRIM: audit_trim_trees() "trim"
- audit_add_tree_rule() iterate_mounts err "add"
- audit_add_rule()
- audit_rule_change()
- AUDIT_ADD_RULE -F dir=:
- AUDIT_MAKE_EQUIV: audit_tag_tree() iterate_mounts err "equiv"
- from audit_kill_trees()
- __audit_free() "free"
- do_exit()
- copy_process() err
- __audit_syscall_exit() "exit"
- from evict_chunk() "evict"
- audit_tree_freeing_mark()
- audit_tree_ops.freeing_mark
- audit_watch_log_rule_change()
- audit_update_watch() "updated_rules(watch:inval)" : "updated_rules(watch:set)"
- audit_watch_handle_event() FS_CREATE|FS_MOVED_TO, FS_DELETE|FS_MOVED_FROM
- audit_watch_fsnotify_ops.handle_event
- audit_remove_parent_watches() "remove_rule(watch:parent)"
- audit_watch_handle_event() FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF
- audit_watch_fsnotify_ops.handle_event
See: https://github.com/linux-audit/audit-kernel/issues/50
See: https://github.com/linux-audit/audit-kernel/issues/59
Changelog:
v2:
- re-order audit_log_exit() and audit_kill_trees()
- drop EOE reordering patch
- rebase on 4.18-rc1 (audit/next)
Richard Guy Briggs (6):
audit: give a clue what CONFIG_CHANGE op was involved
audit: add syscall information to CONFIG_CHANGE records
audit: exclude user records from syscall context
audit: hand taken context to audit_kill_trees for syscall logging
audit: kill trees before logging syscall exit for exit/free
audit: extend config_change mark/watch/tree rule changes
kernel/audit.c | 20 ++++++++++++++------
kernel/audit.h | 4 ++--
kernel/audit_fsnotify.c | 4 ++--
kernel/audit_tree.c | 28 +++++++++++++++-------------
kernel/audit_watch.c | 8 +++++---
kernel/auditfilter.c | 2 +-
kernel/auditsc.c | 9 ++++-----
7 files changed, 43 insertions(+), 32 deletions(-)
--
1.8.3.1
6 years, 1 month
[PATCH ghak10 v5 0/2] audit: Log modifying adjtimex(2) calls
by Ondrej Mosnacek
This patchset implements more detailed auditing of the adjtimex(2)
syscall in order to make it possible to:
a) distinguish modifying vs. read-only calls in the audit log
b) reconstruct from the audit log what changes were made and how they
have influenced the system clock
The main motivation is to be able to detect an adversary that tries to
confuse the audit timestamps by changing system time via adjtimex(2),
but at the same time avoid flooding the audit log with records of benign
read-only adjtimex(2) calls.
The current version of the patchset logs the following changes:
- direct injection of timekeeping offset
- adjustment of timekeeping's TAI offset
- NTP value adjustments:
- time_offset
- time_freq
- time_status
- time_adjust
- tick_usec
Changes to the following NTP values are not logged, as they are not
important for security:
- time_maxerror
- time_esterror
- time_constant
Audit kernel GitHub issue: https://github.com/linux-audit/audit-kernel/issues/10
Changes in v5:
- Dropped logging of some less important changes and update commit messages
- No longer mark the patchset as RFC
v4: https://www.redhat.com/archives/linux-audit/2018-August/msg00023.html
Changes in v4:
- Squashed first two patches into one
- Renamed ADJNTPVAL's "type" field to "op" to align with audit record
conventions
- Minor commit message editing
- Cc timekeeping/NTP people for feedback
v3: https://www.redhat.com/archives/linux-audit/2018-July/msg00001.html
Changes in v3:
- Switched to separate records for each variable
- Both old and new value is now reported for each change
- Injecting offset is reported via a separate record (since this
offset consists of two values and is added directly to the clock,
i.e. it doesn't make sense to log old and new value)
- Added example records produced by chronyd -q (see the commit message
of the last patch)
v2: https://www.redhat.com/archives/linux-audit/2018-June/msg00114.html
Changes in v2:
- The audit_adjtime() function has been modified to only log those
fields that contain values that are actually used, resulting in more
compact records.
- The audit_adjtime() call has been moved to do_adjtimex() in
timekeeping.c
- Added an additional patch (for review) that simplifies the detection
if the syscall is read-only.
v1: https://www.redhat.com/archives/linux-audit/2018-June/msg00095.html
Ondrej Mosnacek (2):
audit: Add functions to log time adjustments
timekeeping/ntp: Audit clock/NTP params adjustments
include/linux/audit.h | 21 +++++++++++++++++++++
include/uapi/linux/audit.h | 2 ++
kernel/auditsc.c | 15 +++++++++++++++
kernel/time/ntp.c | 38 ++++++++++++++++++++++++++++++--------
kernel/time/timekeeping.c | 3 +++
5 files changed, 71 insertions(+), 8 deletions(-)
--
2.17.1
6 years, 3 months
[RFC PATCH ghak10 v4 0/2] audit: Log modifying adjtimex(2) calls
by Ondrej Mosnacek
Hi,
this patchset implements more detailed auditing of the adjtimex(2)
syscall in order to make it possible to:
a) distinguish modifying vs. read-only calls in the audit log
b) reconstruct from the audit log what changes were made and how they
have influenced the system clock
The main motivation is to be able to detect an adversary that tries to
confuse the audit timestamps by changing system time via adjtimex(2),
but at the same time avoid flooding the audit log with records of benign
read-only adjtimex(2) calls.
@John or other timekeeping/NTP folks: We had a discussion on the audit
ML on which of the internal timekeeping/NTP variables we should actually
log changes for. We are only interested in variables that can (directly
or indirectly) cause noticeable changes to the system clock, but since we
have only limited understanding of the NTP code, we would like to ask
you for advice on which variables are security relevant.
Right now, the patchset is conservative and logs all changes that can be
done via adjtimex(2):
- direct injection of timekeeping offset (obviously relevant)
- adjustment of timekeeping's TAI offset
- NTP value adjustments:
- time_offset (probably important)
- time_freq (maybe not important?)
- time_status (likely important, can cause leap second injection)
- time_maxerror (maybe not important?)
- time_esterror (maybe not important?)
- time_constant (???)
- time_adjust (sounds important)
- tick_usec (???)
Could you please give us some hints on the effect of changing these
variables and whether you think that it is important to log their
changes?
Thanks a lot!
GitHub issue: https://github.com/linux-audit/audit-kernel/issues/10
Changes in v4:
- Squashed first two patches into one
- Rename ADJNTPVAL's "type" field to "op" to align with audit record
conventions
- Minor commit message editing
- Cc timekeeping/NTP people for feedback
v3: https://www.redhat.com/archives/linux-audit/2018-July/msg00001.html
Changes in v3:
- Switched to separate records for each variable
- Both old and new value is now reported for each change
- Injecting offset is reported via a separate record (since this
offset consists of two values and is added directly to the clock,
i.e. it doesn't make sense to log old and new value)
- Added example records produced by chronyd -q (see the commit message
of the last patch)
v2: https://www.redhat.com/archives/linux-audit/2018-June/msg00114.html
Changes in v2:
- The audit_adjtime() function has been modified to only log those
fields that contain values that are actually used, resulting in more
compact records.
- The audit_adjtime() call has been moved to do_adjtimex() in
timekeeping.c
- Added an additional patch (for review) that simplifies the detection
if the syscall is read-only.
v1: https://www.redhat.com/archives/linux-audit/2018-June/msg00095.html
Ondrej Mosnacek (2):
audit: Add functions to log time adjustments
timekeeping/ntp: Audit clock/NTP params adjustments
include/linux/audit.h | 21 ++++++++++++++++
include/uapi/linux/audit.h | 2 ++
kernel/auditsc.c | 15 ++++++++++++
kernel/time/ntp.c | 50 ++++++++++++++++++++++++++++++--------
kernel/time/timekeeping.c | 3 +++
5 files changed, 81 insertions(+), 10 deletions(-)
--
2.17.1
6 years, 3 months
[PATCH 0/10 v2] audit: Fix various races when tagging and untagging mounts
by Jan Kara
Hello,
this is a second revision of the series that addresses problems I have
identified when trying to understand how exactly is kernel/audit_tree.c using
generic fsnotify framework. I hope I have understood all the interactions right
but careful review is certainly welcome.
The patches have been tested by a stress test I have written which mounts &
unmounts filesystems in the directory tree while adding and removing audit
rules for this tree in parallel and accessing the tree to generate events.
Still some real-world testing would be welcome.
Changes since v1:
* Split the last patch to ease review
* Rewrite test script so that it can be included in audit testsuite
* Some cleanups and improvements suggested by Amir
Honza
6 years, 3 months
SOFTWARE_UPDATE on RHEL 7.6
by Maupertuis Philippe
Hi,
I have tried to get the SOFTWARE_UPDATE events on a new RHEL 7.6 beta 1 with audit rebased on 2.8.4
When installing a new rpm I get the corresponding event.
The text format is very easily readable :)
Unfortunately when I remove the package I get nothing.
Is it the intending behavior ?
If updates are pushed through Redhat satellite or Spacewalk would I get the event ?
Philippe
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6 years, 3 months
configuration for busy docker host
by Frederik Bosch
Hello Audit team,
As I have not found a location anywhere else on the web, I am sending my
question to this list. I have an Ubuntu 18.04 machine with auditd and it
acts as a Docker Host machine. I have hardened the system via this
package: https://github.com/konstruktoid/hardening which installs auditd
with the configuration to be found here:
https://github.com/konstruktoid/hardening/blob/master/misc/audit.rules.
The problems I have are related to the directives -f and -b. The
hardening package uses -b 8192 and -f 2. That results in a kernel panic
very quickly because of audit backlog limit exceeded, and that causes a
reboot of the system. Now I wonder what a good configuration would be. I
started reading on the subject and read that -f 2 is probably the best
for security reasons. However, I do not want to have a system that
panics very quickly and reboots.
Should I simply increase the backlog to much higher numbers? Or should I
change -f to not cause a kernel panic? Or am I missing something and
should I change some other configuration? Thanks for your help.
Kind regards,
Frederik Bosch
6 years, 4 months
