[RFC PATCH V1 02/12] audit: log container info of syscalls

[Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Create a new audit record AUDIT_CONTAINER_INFO to document the container
ID 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=UNKNOWN[1332] msg=audit(1519924845.499:257): op=task contid=123458

See: https://github.com/linux-audit/audit-kernel/issues/32
Signed-off-by: Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 include/linux/audit.h      |  5 +++++
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 20 ++++++++++++++++++++
 kernel/auditsc.c           |  2 ++
 4 files changed, 28 insertions(+)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index fe4ba3f..3acbe9d 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -154,6 +154,8 @@ extern void		    audit_log_link_denied(const char *operation,
 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_container_info(struct task_struct *tsk,
+				     struct audit_context *context);
 
 extern int		    audit_update_lsm_rules(void);
 
@@ -205,6 +207,9 @@ 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_container_info(struct task_struct *tsk,
+					    struct audit_context *context);
+{ }
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */
 
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 921a71f..e83ccbd 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_INFO	1332	/* Container ID information */
 
 #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 5c25449..8dc745f 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1996,6 +1996,26 @@ void audit_log_session_info(struct audit_buffer *ab)
 	audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
 }
 
+/*
+ * audit_log_container_info - report container info
+ * @tsk: task to be recorded
+ * @context: task or local context for record
+ */
+int audit_log_container_info(struct task_struct *tsk, struct audit_context *context)
+{
+	struct audit_buffer *ab;
+
+	if (!audit_containerid_set(tsk))
+		return 0;
+	/* Generate AUDIT_CONTAINER_INFO with container ID */
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER_INFO);
+	if (!ab)
+		return -ENOMEM;
+	audit_log_format(ab, "contid=%llu", audit_get_containerid(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 0ee1e59..f015c25 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1453,6 +1453,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 
 	audit_log_proctitle(tsk, context);
 
+	audit_log_container_info(tsk, context);
+
 	/* 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