[PATCH ghak90 V8 00/16] audit: implement container identifier
by Richard Guy Briggs
Implement kernel audit container identifier.
This patchset is an eighth based on the proposal document (V4) posted:
https://www.redhat.com/archives/linux-audit/2019-September/msg00052.html
The first patch was the last patch from ghak81 that was absorbed into
this patchset since its primary justification is the rest of this
patchset.
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 reading the audit container identifier from the
proc filesystem for debugging. This patch wasn't planned for upstream
inclusion but is starting to become more likely.
The fourth converts over from a simple u64 to a list member that includes
owner information to check for descendancy, allow process injection into
a container and prevent id reuse by other orchestrators.
The fifth logs the drop of an audit container identifier once all tasks
using that audit container identifier have exited.
The 6th implements the auxiliary record AUDIT_CONTAINER_ID if an audit
container identifier is associated with an event. This patch requires
userspace support for proper type display.
The 7th adds audit daemon signalling provenance through audit_sig_info2.
The 8th creates a local audit context to be able to bind a standalone
record with a locally created auxiliary record.
The 9th patch adds audit container identifier records to the user
standalone records.
The 10th 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 11th adds network namespace audit container identifier labelling
based on member tasks' audit container identifier labels which supports
standalone netfilter records that don't have a task context and lists
each container to which that net namespace belongs.
The 12th checks that the target is a descendant for nesting and
refactors to avoid a duplicate of the copied function.
The 13th adds tracking and reporting for container nesting.
This enables kernel filtering and userspace searches of nested audit
container identifiers.
The 14th checks and clamps the nesting depth of containers while the
15th checks and clamps the total number of audit container identifiers
sharing one network namespace. The combination of these two pararmeters
prevents the overflow of the contid field in CONTAINER_* records.
The 16th adds a mechanism to allow a process to be designated as a
container orchestrator/engine in non-init user namespaces.
Example: Set an audit container identifier of 123456 to the "sleep" task:
sleep 2&
child=$!
echo 123456 > /proc/$child/audit_containerid; echo $?
ausearch -ts recent -m container_op
echo child:$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 contid=123456 old-contid=18446744073709551615
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_ID msg=audit(2018-06-06 12:46:31.707:26953) : 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
Example: Test multiple containers on one netns:
sleep 5 &
child1=$!
containerid1=123451
echo $containerid1 > /proc/$child1/audit_containerid
sleep 5 &
child2=$!
containerid2=123452
echo $containerid2 > /proc/$child2/audit_containerid
iptables -I INPUT -i lo -p icmp --icmp-type echo-request -j AUDIT --type accept
iptables -I INPUT -t mangle -i lo -p icmp --icmp-type echo-request -j MARK --set-mark 0x12345555
sleep 1;
bash -c "ping -q -c 1 127.0.0.1 >/dev/null 2>&1"
sleep 1;
ausearch -i -m NETFILTER_PKT -ts boot|grep mark=0x12345555
ausearch -i -m NETFILTER_PKT -ts boot|grep contid=|grep $containerid1|grep $containerid2
This should produce an event such as:
type=NETFILTER_PKT msg=audit(03/15/2019 14:16:13.369:244) : mark=0x12345555 saddr=127.0.0.1 daddr=127.0.0.1 proto=icmp
type=CONTAINER_ID msg=audit(03/15/2019 14:16:13.369:244) : contid=123452,123451
Includes the last patch of https://github.com/linux-audit/audit-kernel/issues/81
Please see the github audit kernel issue for the main feature:
https://github.com/linux-audit/audit-kernel/issues/90
and the kernel filter code:
https://github.com/linux-audit/audit-kernel/issues/91
and the network support:
https://github.com/linux-audit/audit-kernel/issues/92
Please see the github audit userspace issue for supporting record types:
https://github.com/linux-audit/audit-userspace/issues/51
and filter code:
https://github.com/linux-audit/audit-userspace/issues/40
Please see the github audit testsuiite issue for the test case:
https://github.com/linux-audit/audit-testsuite/issues/64
https://github.com/rgbriggs/audit-testsuite/tree/ghat64-contid
https://githu.com/linux-audit/audit-testsuite/pull/91
Please see the github audit wiki for the feature overview:
https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
The code is also posted at:
git://toccata2.tricolour.ca/linux-2.6-rgb.git ghak90-audit-containerID.v8
Changelog:
v8
- rebase on v5.5-rc1 audit/next
- remove subject attrs in CONTAINER_OP record
- group audit_contid_list_lock with audit_contid_hash
- in audit_{set,log}_contid(), break out of loop after finding target
- use target var to size kmalloc
- rework audit_cont_owner() to bool audit_contid_isowner() and move to where used
- create static void audit_cont_hold(struct audit_contobj *cont) { refcount_inc(&cont->refcount); }
- rename audit_cont{,_*} refs to audit_contobj{,_*}
- prefix special local functions with _ [audit_contobj*()]
- protect contid list traversals with rcu_read_lock() and updates with audit_contid_list_lock
- protect real_parent in audit_contid_depth() with rcu_dereference
- give new contid field nesting format in patch description
- squash task_is_descendant()
- squash support for NETFILTER_PKT into network namespaces
- limit nesting depth based on record length overflow, bandwidth and storage
- implent control for audit container identifier nesting depth limit
- make room for audit_bpf patches (bump CONTAINER_ID to 1335)
- squash proc interface into capcontid
- remove netlink access to loginuid/sessionid/contid/capcontid
- delete 32k contid limit patch
- document potential overlap between signal delivery and contid reuse
- document audit_contobj_list_lock coverage
- document disappearing orch task injection limitation
- limit the number of containers that can be associated with a network namespace
- implent control for audit container identifier netns count limit
v7
- remove BUG() in audit_comparator64()
- rebase on v5.2-rc1 audit/next
- resolve merge conflict with ghak111 (signal_info regardless syscall)
- resolve merge conflict with ghak73 (audit_field_valid)
- resolve merge conflict with ghak64 (saddr_fam filter)
- resolve merge conflict with ghak10 (ntp audit) change AUDIT_CONTAINER_ID from 1332 to 1334
- rebase on v5.3-rc1 audit/next
- track container owner
- only permit setting contid of descendants for nesting
- track drop of contid and permit reuse
- track and report container nesting
- permit filtering on any nested contid
- set/get contid and loginuid/sessionid via netlink
- implement capcontid to enable orchestrators in non-init user
namespaces
- limit number of containers
- limit depth of container nesting
v6
- change TMPBUFLEN from 11 to 21 to cover the decimal value of contid
u64 (nhorman)
- fix bug overwriting ctx in struct audit_sig_info, move cid above
ctx[0] (nhorman)
- fix bug skipping remaining fields and not advancing bufp when copying
out contid in audit_krule_to_data (omosnacec)
- add acks, tidy commit descriptions, other formatting fixes (checkpatch
wrong on audit_log_lost)
- cast ull for u64 prints
- target_cid tracking was moved from the ptrace/signal patch to
container_op
- target ptrace and signal records were moved from the ptrace/signal
patch to container_id
- auditd signaller tracking was moved to a new AUDIT_SIGNAL_INFO2
request and record
- ditch unnecessary list_empty() checks
- check for null net and aunet in audit_netns_contid_add()
- swap CONTAINER_OP contid/old-contid order to ease parsing
v5
- address loginuid and sessionid syscall scope in ghak104
- address audit_context in CONFIG_AUDIT vs CONFIG_AUDITSYSCALL in ghak105
- remove tty patch, addressed in ghak106
- rebase on audit/next v5.0-rc1
w/ghak59/ghak104/ghak103/ghak100/ghak107/ghak105/ghak106/ghak105sup
- update CONTAINER_ID to CONTAINER_OP in patch description
- move audit_context in audit_task_info to CONFIG_AUDITSYSCALL
- move audit_alloc() and audit_free() out of CONFIG_AUDITSYSCALL and into
CONFIG_AUDIT and create audit_{alloc,free}_syscall
- use plain kmem_cache_alloc() rather than kmem_cache_zalloc() in audit_alloc()
- fix audit_get_contid() declaration type error
- move audit_set_contid() from auditsc.c to audit.c
- audit_log_contid() returns void
- audit_log_contid() handed contid rather than tsk
- switch from AUDIT_CONTAINER to AUDIT_CONTAINER_ID for aux record
- move audit_log_contid(tsk/contid) & audit_contid_set(tsk)/audit_contid_valid(contid)
- switch from tsk to current
- audit_alloc_local() calls audit_log_lost() on failure to allocate a context
- add AUDIT_USER* non-syscall contid record
- cosmetic cleanup double parens, goto out on err
- ditch audit_get_ns_contid_list_lock(), fix aunet lock race
- switch from all-cpu read spinlock to rcu, keep spinlock for write
- update audit_alloc_local() to use ktime_get_coarse_real_ts64()
- add nft_log support
- add call from do_exit() in audit_free() to remove contid from netns
- relegate AUDIT_CONTAINER ref= field (was op=) to debug patch
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 (16):
audit: collect audit task parameters
audit: add container id
audit: read container ID of a process
audit: convert to contid list to check for orch/engine ownership
audit: log drop of contid on exit of last task
audit: log container info of syscalls
audit: add contid support for signalling the audit daemon
audit: add support for non-syscall auxiliary records
audit: add containerid support for user records
audit: add containerid filtering
audit: add support for containerid to network namespaces
audit: contid check descendancy and nesting
audit: track container nesting
audit: check contid depth and add limit config param
audit: check contid count per netns and add config param limit
audit: add capcontid to set contid outside init_user_ns
fs/proc/base.c | 112 +++++++-
include/linux/audit.h | 140 +++++++++-
include/linux/nsproxy.h | 2 +-
include/linux/sched.h | 10 +-
include/uapi/linux/audit.h | 14 +-
init/init_task.c | 3 +-
init/main.c | 2 +
kernel/audit.c | 626 +++++++++++++++++++++++++++++++++++++++++++-
kernel/audit.h | 29 ++
kernel/auditfilter.c | 61 +++++
kernel/auditsc.c | 91 +++++--
kernel/fork.c | 11 +-
kernel/nsproxy.c | 27 +-
kernel/sched/core.c | 33 +++
net/netfilter/nft_log.c | 11 +-
net/netfilter/xt_AUDIT.c | 11 +-
security/selinux/nlmsgtab.c | 1 +
security/yama/yama_lsm.c | 33 ---
18 files changed, 1115 insertions(+), 102 deletions(-)
--
1.8.3.1
3 years, 11 months
[PATCH] audit: mark expected switch fall-through
by Gustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warning:
kernel/auditfilter.c: In function ‘audit_krule_to_data’:
kernel/auditfilter.c:668:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
^
kernel/auditfilter.c:674:3: note: here
default:
^~~~~~~
Warning level 3 was used: -Wimplicit-fallthrough=3
Notice that, in this particular case, the code comment is modified
in accordance with what GCC is expecting to find.
This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: Gustavo A. R. Silva <gustavo(a)embeddedor.com>
---
kernel/auditfilter.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index add360b46b38..63f8b3f26fab 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -670,7 +670,7 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
data->values[i] = AUDIT_UID_UNSET;
break;
}
- /* fallthrough if set */
+ /* fall through - if set */
default:
data->values[i] = f->val;
}
--
2.20.1
4 years
Re: [PATCH v2] kernel: audit.c: Add __rcu notation to RCU pointer
by Joel Fernandes
On Thu, Nov 28, 2019 at 09:02:03PM +0530, Amol Grover wrote:
> add __rcu notation to RCU protected global pointer auditd_conn
Again, please use proper punctuation and captilization. This is unacceptable.
Please put more effort into changelog.
Otherwise the patch diff itself looks good to me, with the above nit
corrected, you could add my tag to the next revision:
Reviewed-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
thanks,
- Joel
>
> Fixes multiple instances of sparse error:
> error: incompatible types in comparison expression
> (different address spaces)
>
> Signed-off-by: Amol Grover <frextrite(a)gmail.com>
> ---
> v2:
> - fix erroneous RCU pointer initialization
>
> kernel/audit.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/audit.c b/kernel/audit.c
> index da8dc0db5bd3..ff7cfc61f53d 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -102,12 +102,13 @@ struct audit_net {
> * This struct is RCU protected; you must either hold the RCU lock for reading
> * or the associated spinlock for writing.
> */
> -static struct auditd_connection {
> +struct auditd_connection {
> struct pid *pid;
> u32 portid;
> struct net *net;
> struct rcu_head rcu;
> -} *auditd_conn = NULL;
> +};
> +static struct auditd_connection __rcu *auditd_conn;
> static DEFINE_SPINLOCK(auditd_conn_lock);
>
> /* If audit_rate_limit is non-zero, limit the rate of sending audit records
> --
> 2.24.0
>
4 years, 1 month
[PATCH ghak25 v2 0/9] Address NETFILTER_CFG issues
by Richard Guy Briggs
There were questions about the presence and cause of unsolicited syscall events
in the logs containing NETFILTER_CFG records and sometimes unaccompanied
NETFILTER_CFG records.
During testing at least the following list of events trigger NETFILTER_CFG
records and the syscalls related (There may be more events that will trigger
this message type.):
init_module, finit_module: modprobe
setsockopt: iptables-restore, ip6tables-restore, ebtables-restore
unshare: (h?)ostnamed
clone: libvirtd
The syscall events unsolicited by any audit rule were found to be caused by a
missing !audit_dummy_context() check before creating a NETFILTER_CFG
record and issuing the record immediately rather than saving the
information to create the record at syscall exit.
Check !audit_dummy_context() before creating the NETFILTER_CFG record.
The vast majority of unaccompanied records are caused by the fedora default
rule: "-a never,task" and the occasional early startup one is I believe caused
by the iptables filter table module hard linked into the kernel rather than a
loadable module. The !audit_dummy_context() check above should avoid them.
A couple of other factors should help eliminate unaccompanied records
which include commit cb74ed278f80 ("audit: always enable syscall
auditing when supported and audit is enabled") which makes sure that
when audit is enabled, so automatically is syscall auditing, and ghak66
which addressed initializing audit before PID 1.
Ebtables module initialization to register tables doesn't generate records
because it was never hooked in to audit. Recommend adding audit hooks to log
this.
Table unregistration was never logged, which is now covered.
Seemingly duplicate records are not actually exact duplicates that are caused
by netfilter table initialization in different network namespaces from the same
syscall. Recommend adding the network namespace ID (proc inode and dev)
to the record to make this obvious (address later with ghak79 after nsid
patches).
See: https://github.com/linux-audit/audit-kernel/issues/25
See: https://github.com/linux-audit/audit-kernel/issues/35
See: https://github.com/linux-audit/audit-kernel/issues/43
See: https://github.com/linux-audit/audit-kernel/issues/44
Changelog:
v2
- Rebase (audit/next 5.5-rc1) to get audit_context access and ebt_register_table ret code
- Split x_tables and ebtables updates
- Check audit_dummy_context
- Store struct audit_nfcfg params in audit_context, abstract to audit_nf_cfg() call
- Restore back to "table, family, entries" from "family, table, entries"
- Log unregistration of tables
- Add "op=" at the end of the AUDIT_NETFILTER_CFG record
- Defer nsid patch (ghak79) to once nsid patchset upstreamed (ghak32)
- Add ghak refs
- Ditch NETFILTER_CFGSOLO record
Richard Guy Briggs (9):
netfilter: normalize x_table function declarations
netfilter: normalize ebtables function declarations
netfilter: normalize ebtables function declarations II
audit: record nfcfg params
netfilter: x_tables audit only on syscall rule
netfilter: ebtables audit only on syscall rule
netfilter: ebtables audit table registration
netfilter: add audit operation field
netfilter: audit table unregister actions
include/linux/audit.h | 11 ++++
kernel/auditsc.c | 18 +++++
net/bridge/netfilter/ebtables.c | 142 ++++++++++++++++++++--------------------
net/netfilter/x_tables.c | 56 +++++++---------
4 files changed, 124 insertions(+), 103 deletions(-)
--
1.8.3.1
4 years, 2 months
[PATCH ghak28 V4] audit: log audit netlink multicast bind and unbind events
by Richard Guy Briggs
Log information about programs connecting to and disconnecting from the
audit netlink multicast socket. This is needed so that during
investigations a security officer can tell who or what had access to the
audit trail. This helps to meet the FAU_SAR.2 requirement for Common
Criteria. Here is the systemd startup event:
type=UNKNOWN[1335] msg=audit(2020-01-17 10:30:33.731:6) : pid=1 uid=root auid=unset tty=(none) ses=unset subj=kernel comm=systemd exe=/usr/lib/systemd/systemd nl-mcgrp=1 op=connect res=yes
And the events from the test suite:
type=PROCTITLE msg=audit(2020-01-17 10:36:24.050:294) : proctitle=/usr/bin/perl -w amcast_joinpart/test
type=SOCKADDR msg=audit(2020-01-17 10:36:24.050:294) : saddr={ saddr_fam=netlink nlnk-fam=16 nlnk-pid=0 }
type=SYSCALL msg=audit(2020-01-17 10:36:24.050:294) : arch=x86_64 syscall=bind success=yes exit=0 a0=0x7 a1=0x55d65cb79090 a2=0xc a3=0x0 items=0 ppid=671 pid=674 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=3 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=UNKNOWN[1335] msg=audit(2020-01-17 10:36:24.050:294) : pid=674 uid=root auid=root tty=ttyS0 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=connect res=yes
type=UNKNOWN[1335] msg=audit(2020-01-17 10:36:24.051:295) : pid=674 uid=root auid=root tty=ttyS0 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=perl exe=/usr/bin/perl nl-mcgrp=1 op=disconnect res=yes
Please see the upstream issue tracker:
https://github.com/linux-audit/audit-kernel/issues/28
https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Multicast-Sock...
https://github.com/rgbriggs/audit-testsuite/compare/ghak28-mcast-part-join
Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
---
Note: msg type 1334 was skipped due to BPF accepted in another tree.
Note: v5 due to previous 2014-10-07, 2015-07-23, 2016-11-30, 2017-10-13
Note: subj attrs included due to missing syscall record for systemd (audit=1)
Note: tried refactor of subj attrs, but this is yet another new order.
---
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 48 ++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 45 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 3ad935527177..67fb24472dc2 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -116,6 +116,7 @@
#define AUDIT_FANOTIFY 1331 /* Fanotify access decision */
#define AUDIT_TIME_INJOFFSET 1332 /* Timekeeping offset injected */
#define AUDIT_TIME_ADJNTPVAL 1333 /* NTP value adjustment */
+#define AUDIT_EVENT_LISTENER 1335 /* Task joined multicast read socket */
#define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
#define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */
diff --git a/kernel/audit.c b/kernel/audit.c
index 17b0d523afb3..478259f3fa53 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1520,20 +1520,60 @@ static void audit_receive(struct sk_buff *skb)
audit_ctl_unlock();
}
+/* Log information about who is connecting to the audit multicast socket */
+static void audit_log_multicast_bind(int group, const char *op, int err)
+{
+ const struct cred *cred;
+ struct tty_struct *tty;
+ char comm[sizeof(current->comm)];
+ struct audit_buffer *ab;
+
+ if (!audit_enabled)
+ return;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+ if (!ab)
+ return;
+
+ cred = current_cred();
+ tty = audit_get_tty();
+ audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
+ task_pid_nr(current),
+ from_kuid(&init_user_ns, cred->uid),
+ from_kuid(&init_user_ns, audit_get_loginuid(current)),
+ tty ? tty_name(tty) : "(none)",
+ audit_get_sessionid(current));
+ audit_put_tty(tty);
+ audit_log_task_context(ab); /* subj= */
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, get_task_comm(comm, current));
+ audit_log_d_path_exe(ab, current->mm); /* exe= */
+ audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
+ audit_log_end(ab);
+}
+
/* Run custom bind function on netlink socket group connect or bind requests. */
-static int audit_bind(struct net *net, int group)
+static int audit_multicast_bind(struct net *net, int group)
{
+ int err = 0;
+
if (!capable(CAP_AUDIT_READ))
- return -EPERM;
+ err = -EPERM;
+ audit_log_multicast_bind(group, "connect", err);
+ return err;
+}
- return 0;
+static void audit_multicast_unbind(struct net *net, int group)
+{
+ audit_log_multicast_bind(group, "disconnect", 0);
}
static int __net_init audit_net_init(struct net *net)
{
struct netlink_kernel_cfg cfg = {
.input = audit_receive,
- .bind = audit_bind,
+ .bind = audit_multicast_bind,
+ .unbind = audit_multicast_unbind,
.flags = NL_CFG_F_NONROOT_RECV,
.groups = AUDIT_NLGRP_MAX,
};
--
1.8.3.1
4 years, 2 months
ausearch on the fly
by MAUPERTUIS, PHILIPPE
Hi,
We are centralizing the audit logs with rsyslog.
The SIEM behind the central log server is unable to process the raw logs.
We would like to push the ausearch result in CSV format in real time or near real time.
Is there a way to have ausearch working from a pipe and and waiting when no logs are received
Regards
Philippe
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4 years, 3 months
USBguard bug
by Burn Alting
All,
I need some advice.
Currently when the USB management framework, usbguard (
https://github.com/USBGuard/usbguard), is building it's key-value pairs prior to
calling audit_log_user_message() with a AUDIT_USER_DEVICE type, it looks at each
value and decides to hex encode the value if any character in the value matches
the expression (str[i] == '"' || str[i] < 0x21 || str[i] == 0x7F). This can be found
in https://github.com/USBGuard/usbguard/blob/master/src/Daemon/LinuxAuditBac...
where it makes the call
audit_log_user_message(_audit_fd, AUDIT_USER_DEVICE, message.c_str(),
/*hostname=*/nullptr, /*addr=*/nullptr, /*tty=*/nullptr, result);
As a result, one sees audit events such as
type=USER_DEVICE msg=audit(1580255002.606:352190): pid=3115 uid=0 auid=4294967295
ses=4294967295 subj=system_u:system_r:unconfined_service_t:s0 msg='op="changed-
authorization-state-for" device="/devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.3"
target="allow"
device_rule=626C6F636B20696420303738313A353539312073657269616C2022344335333030303132
323034313231303533313322206E616D652022556C7472612055534220332E3022206861736820227953
6D433045594970734A575666474436414854774577712F624974344631466A78785856306C3552356B3D
2220706172656E742D6861736820226B763376322B726E713951765949332F48624A314556397664756A
5A30615643512F43474259496B4542303D22207669612D706F72742022312D312E332220776974682D69
6E746572666163652030383A30363A3530 exe="/usr/sbin/usbguard-daemon" hostname=? addr=?
terminal=? res=success' UID="root" AUID="unset"
where device_rule started as
block id 0781:5591 serial "4C530001220412105313" name "Ultra USB 3.0" hash
"ySmC0EYIpsJWVfGD6AHTwEwq/bIt4F1FjxxXV0l5R5k=" parent-hash
"kv3v2+rnq9QvYI3/HbJ1EV9vdujZ0aVCQ/CGBYIkEB0=" via-port "1-1.3" with-interface
08:06:50
or
type=USER_DEVICE msg=audit(1580255002.605:352187): pid=3115 uid=0 auid=4294967295
ses=4294967295 subj=system_u:system_r:unconfined_service_t:s0 msg='op="discovered-
device" device="/devices/pci0000:00/0000:00:1d.0/usb2/2-1"
device_rule=616C6C6F7720696420383038373A303032342073657269616C202222206E616D65202222
206861736820225A78377630464D51456A53634B534146454E41696F624573314F47505042305957522B
79584443564530343D2220706172656E742D68617368202257484254784E61456F4D474E534E6333314B
70464E53416546463448624C4D51675342714F526C433653383D22207669612D706F72742022322D3122
20776974682D696E746572666163652030393A30303A3030 exe="/usr/sbin/usbguard-daemon"
hostname=? addr=? terminal=? res=success' UID="root" AUID="unset"
where device_rule started as
allow id 8087:0024 serial "" name "" hash
"Zx7v0FMQEjScKSAFENAiobEs1OGPPB0YWR+yXDCVE04=" parent-hash
"WHBTxNaEoMGNSNc31KpFNSAeFF4HbLMQgSBqORlC6S8=" via-port "2-1" with-interface
09:00:00
I have a number of questions
- What is the best recommendation I can make in a bug report I'd like to raise so
that the auparse library can reliably interpret all their key's values?
- Should I also request they actually provide hostname and addr values to
audit_log_user_message()?
- If one want them to identify the user who participates in the activity what is the
best recommendation to make in terms of keys in the message?
Thanks in advance
4 years, 3 months
audit: CONFIG_CHANGE don't log internal bookkeeping as an event
by Steve Grubb
Common Criteria calls out for any action that modifies the audit trail to
be recorded. That usually is interpreted to mean insertion or removal of
rules. It is not required to log modification of the inode information
since the watch is still in effect. Additionally, if the rule is a never
rule and the underlying file is one they do not want events for, they
get an event for this bookkeeping update against their wishes.
Since no device/inode info is logged at insertion and no device/inode
information is logged on update, there is nothing meaningful being
communicated to the admin by the CONFIG_CHANGE updated_rules event. One
can assume that the rule was not "modified" because it is still watching
the intended target. If the device or inode cannot be resolved, then
audit_panic is called which is sufficient.
The correct resolution is to drop logging config_update events since
the watch is still in effect but just on another unknown inode.
Signed-off-by: Steve Grubb <sgrubb(a)redhat.com>
---
kernel/audit_watch.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 4508d5e0cf69..8a8fd732ff6d 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -302,8 +302,6 @@ static void audit_update_watch(struct audit_parent *parent,
if (oentry->rule.exe)
audit_remove_mark(oentry->rule.exe);
- audit_watch_log_rule_change(r, owatch, "updated_rules");
-
call_rcu(&oentry->rcu, audit_free_rule_rcu);
}
--
2.24.1
4 years, 3 months
[GIT PULL] Audit patch for v5.6
by Paul Moore
Hi Linus,
One small audit patch for the Linux v5.6 merge window, and
unsurprisingly it passes our test suite with flying colors. Please
merge.
Thanks,
-Paul
--
The following changes since commit e42617b825f8073569da76dc4510bfa019b1c35a:
Linux 5.5-rc1 (2019-12-08 14:57:55 -0800)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit.git
tags/audit-pr-20200127
for you to fetch changes up to cb5172d96d16df72db8b55146b0ec00bfd97f079:
audit: Add __rcu annotation to RCU pointer (2019-12-09 15:19:03 -0500)
----------------------------------------------------------------
audit/stable-5.6 PR 20200127
----------------------------------------------------------------
Amol Grover (1):
audit: Add __rcu annotation to RCU pointer
kernel/audit.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--
paul moore
www.paul-moore.com
4 years, 3 months
auditing removable media
by Richard Guy Briggs
Hi Burn, and all,
I've been aware of this issue for a while now, but wasn't directly
working on it. Now that I'm taking a closer look at this issue, I am
wondering how much USBGuard changes the equation?
https://www.kernel.org/doc/Documentation/usb/authorization.txt
https://usbguard.github.io/
https://github.com/USBGuard/usbguard
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/...
It has tools to generate baseline lists of devices, but this is only for
usb. Other interfaces would need to be appropriately instrumented.
- RGB
--
Richard Guy Briggs <rgb(a)redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635
4 years, 3 months
