[RFC PATCH ghak90 (was ghak32) V3 02/10] audit: log container info of syscalls

[Richard Guy Briggs]

Create a new audit record AUDIT_CONTAINER 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=0000000000000000 cap_fi=0000000000000000 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=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0
type=PROCTITLE msg=audit(1519924845.499:257): proctitle=62617368002D6300736C65657020313B206563686F2074657374203E202F746D702F746D70636F6E7461696E65726964
type=CONTAINER msg=audit(1519924845.499:257): op=task 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>
---
 include/linux/audit.h      |  7 +++++++
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 23 +++++++++++++++++++++++
 kernel/auditsc.c           |  3 +++
 4 files changed, 34 insertions(+)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 497cd81..4e1e34e 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -152,6 +152,9 @@ extern void		    audit_log_key(struct audit_buffer *ab,
 extern int audit_log_task_context(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab,
 				struct task_struct *tsk);
+extern int audit_log_contid(struct task_struct *tsk,
+				    struct audit_context *context,
+				    char *op);
 
 extern int		    audit_update_lsm_rules(void);
 
@@ -202,6 +205,10 @@ static inline int audit_log_task_context(struct audit_buffer *ab)
 static inline void audit_log_task_info(struct audit_buffer *ab,
 				       struct task_struct *tsk)
 { }
+static inline int audit_log_contid(struct task_struct *tsk,
+					   struct audit_context *context,
+					   char *op)
+{ }
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */
 
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index c3b1aca..469ab25 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		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 e7478cb..5e150c6 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2048,6 +2048,29 @@ 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
+ * @tsk: task to be recorded
+ * @context: task or local context for record
+ * @op: contid string description
+ */
+int audit_log_contid(struct task_struct *tsk,
+			     struct audit_context *context, char *op)
+{
+	struct audit_buffer *ab;
+
+	if (!audit_contid_set(tsk))
+		return 0;
+	/* Generate AUDIT_CONTAINER record with container ID */
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER);
+	if (!ab)
+		return -ENOMEM;
+	audit_log_format(ab, "op=%s contid=%llu",
+			 op, audit_get_contid(tsk));
+	audit_log_end(ab);
+	return 0;
+}
+
 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 611e926..a3c946c 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1490,10 +1490,13 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 
 	audit_log_proctitle(tsk, context);
 
+	audit_log_contid(tsk, context, "task");
+
 	/* Send end of event record to help user space know we are finished */
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
 	if (ab)
 		audit_log_end(ab);
+
 	if (call_panic)
 		audit_panic("error converting sid to string");
 }
-- 
1.8.3.1