[PATCH ghak90 V5 04/10] audit: log container info of syscalls

[Richard Guy Briggs]

Create a new audit record AUDIT_CONTAINER_ID to document the audit
container identifier of a process if it is present.

Called from audit_log_exit(), syscalls are covered.

A sample raw event:
type=SYSCALL msg=audit(1519924845.499:257): arch=c000003e syscall=257 success=yes exit=3 a0=ffffff9c a1=56374e1cef30 a2=241 a3=1b6 items=2 ppid=606 pid=635 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="bash" exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key="tmpcontainerid"
type=CWD msg=audit(1519924845.499:257): cwd="/root"
type=PATH msg=audit(1519924845.499:257): item=0 name="/tmp/" inode=13863 dev=00:27 mode=041777 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:tmp_t:s0 nametype= PARENT cap_fp=0 cap_fi=0 cap_fe=0 cap_fver=0
type=PATH msg=audit(1519924845.499:257): item=1 name="/tmp/tmpcontainerid" inode=17729 dev=00:27 mode=0100644 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=CREATE cap_fp=0 cap_fi=0 cap_fe=0 cap_fver=0
type=PROCTITLE msg=audit(1519924845.499:257): proctitle=62617368002D6300736C65657020313B206563686F2074657374203E202F746D702F746D70636F6E7461696E65726964
type=CONTAINER_ID msg=audit(1519924845.499:257): contid=123458

See: https://github.com/linux-audit/audit-kernel/issues/90
See: https://github.com/linux-audit/audit-userspace/issues/51
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
Acked-by: Serge Hallyn <serge@xxxxxxxxxx>
Acked-by: Steve Grubb <sgrubb@xxxxxxxxxx>
Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
---
 include/linux/audit.h      |  5 +++++
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 21 +++++++++++++++++++++
 kernel/auditsc.c           |  2 ++
 4 files changed, 29 insertions(+)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 301337776193..43438192ca2a 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -199,6 +199,8 @@ static inline u64 audit_get_contid(struct task_struct *tsk)
 	return tsk->audit->contid;
 }
 
+extern void audit_log_contid(struct audit_context *context, u64 contid);
+
 extern u32 audit_enabled;
 #else /* CONFIG_AUDIT */
 static inline int audit_alloc(struct task_struct *task)
@@ -265,6 +267,9 @@ static inline u64 audit_get_contid(struct task_struct *tsk)
 	return AUDIT_CID_UNSET;
 }
 
+static inline void audit_log_contid(struct audit_context *context, u64 contid)
+{ }
+
 #define audit_enabled AUDIT_OFF
 #endif /* CONFIG_AUDIT */
 
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index d475cf3b4d7f..a6383e28b2c8 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -115,6 +115,7 @@
 #define AUDIT_REPLACE		1329	/* Replace auditd if this packet unanswerd */
 #define AUDIT_KERN_MODULE	1330	/* Kernel Module events */
 #define AUDIT_FANOTIFY		1331	/* Fanotify access decision */
+#define AUDIT_CONTAINER_ID	1332	/* Container ID */
 
 #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 b5c702abeb42..8cc0e88d7f2a 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2127,6 +2127,27 @@ void audit_log_session_info(struct audit_buffer *ab)
 	audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
 }
 
+/*
+ * audit_log_contid - report container info
+ * @context: task or local context for record
+ * @contid: container ID to report
+ */
+void audit_log_contid(struct audit_context *context, u64 contid)
+{
+	struct audit_buffer *ab;
+
+	if (!audit_contid_valid(contid))
+		return;
+	/* Generate AUDIT_CONTAINER_ID record with container ID */
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER_ID);
+	if (!ab)
+		return;
+	audit_log_format(ab, "contid=%llu", contid);
+	audit_log_end(ab);
+	return;
+}
+EXPORT_SYMBOL(audit_log_contid);
+
 void audit_log_key(struct audit_buffer *ab, char *key)
 {
 	audit_log_format(ab, " key=");
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 8090eff7868d..a8c8b44b954d 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1548,6 +1548,8 @@ static void audit_log_exit(void)
 
 	audit_log_proctitle();
 
+	audit_log_contid(context, audit_get_contid(current));
+
 	/* Send end of event record to help user space know we are finished */
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
 	if (ab)
-- 
1.8.3.1