[PATCH V7 04/10] audit: log namespace ID numbers

[Richard Guy Briggs <rgb@redhat.com>]

Log the namespace identifiers (nsfs device ID and inode) of a task in a new
record type (1329) (usually accompanies audit_log_task_info() type=SYSCALL
record) which is used by syscall audits, among others..

Idea first presented:
	https://www.redhat.com/archives/linux-audit/2013-March/msg00020.html

Typical output format would look something like:
	type=NS_INFO msg=audit(1408577535.306:82): pid=374 dev=00:03 netns=7 utsns=2 ipcns=1 pidns=4 userns=3 mntns=5

Suggested-by: Aristeu Rozanski <arozansk@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
---
 include/linux/audit.h            |    8 ++++++++
 include/uapi/linux/audit.h       |    1 +
 kernel/audit.c                   |   35 +++++++++++++++++++++++++++++++++++
 kernel/auditsc.c                 |    2 ++
 security/integrity/ima/ima_api.c |    2 ++
 5 files changed, 48 insertions(+), 0 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index c2e7e3a..acc4685 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -484,6 +484,12 @@ static inline void	    audit_log_secctx(struct audit_buffer *ab, u32 secid)
 extern int audit_log_task_context(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab,
 				struct task_struct *tsk);
+#ifdef CONFIG_NAMESPACES
+extern void		    audit_log_ns_info(struct task_struct *tsk);
+#else
+static inline void	    audit_log_ns_info(struct task_struct *tsk)
+{ }
+#endif
 
 extern int		    audit_update_lsm_rules(void);
 
@@ -540,6 +546,8 @@ 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 void audit_log_ns_info(struct task_struct *tsk)
+{ }
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */
 static inline void audit_log_string(struct audit_buffer *ab, const char *buf)
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index d3475e1..8eca5ae 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -110,6 +110,7 @@
 #define AUDIT_SECCOMP		1326	/* Secure Computing event */
 #define AUDIT_PROCTITLE		1327	/* Proctitle emit event */
 #define AUDIT_FEATURE_CHANGE	1328	/* audit log listing feature changes */
+#define AUDIT_NS_INFO		1329	/* Record process namespace IDs */
 
 #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 72ab759..25d6719 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -65,6 +65,7 @@
 #include <linux/freezer.h>
 #include <linux/tty.h>
 #include <linux/pid_namespace.h>
+#include <linux/proc_ns.h>
 #include <net/netns/generic.h>
 
 #include "audit.h"
@@ -1642,6 +1643,38 @@ void audit_log_session_info(struct audit_buffer *ab)
 	audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
 }
 
+#ifdef CONFIG_NAMESPACES
+void audit_log_ns_info(struct task_struct *tsk)
+{
+	const struct proc_ns_operations **entry;
+	bool end = false;
+	struct audit_buffer *ab;
+	int devprinted = 0;
+
+	if (!audit_enabled || !tsk)
+		return;
+	ab = audit_log_start(current->audit_context, GFP_KERNEL,
+			     AUDIT_NS_INFO);
+	if (!ab)
+		return;
+	audit_log_format(ab, "pid=%d", task_pid_nr(tsk));
+	for (entry = ns_entries; !end; entry++) {
+		struct ns_common *ns = (*entry)->get(tsk);
+
+		if (!devprinted) {
+			audit_log_format(ab, " dev=%02x:%02x", MAJOR(ns->dev),
+					 MINOR(ns->dev));
+			devprinted = 1;
+		}
+		audit_log_format(ab, " %sns=%d", (*entry)->name,
+				 ns->inum);
+		(*entry)->put(ns);
+		end = (*entry)->type == CLONE_NEWNS;
+	}
+	audit_log_end(ab);
+}
+#endif /* CONFIG_NAMESPACES */
+
 void audit_log_key(struct audit_buffer *ab, char *key)
 {
 	audit_log_format(ab, " key=");
@@ -1913,6 +1946,8 @@ void audit_log_link_denied(const char *operation, struct path *link)
 	audit_log_format(ab, " res=0");
 	audit_log_end(ab);
 
+	audit_log_ns_info(current);
+
 	/* Generate AUDIT_PATH record with object. */
 	name->type = AUDIT_TYPE_NORMAL;
 	audit_copy_inode(name, link->dentry, link->dentry->d_inode);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index dc4ae70..dae61fe 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1355,6 +1355,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 	audit_log_key(ab, context->filterkey);
 	audit_log_end(ab);
 
+	audit_log_ns_info(tsk);
+
 	for (aux = context->aux; aux; aux = aux->next) {
 
 		ab = audit_log_start(context, GFP_KERNEL, aux->type);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index b8a27c5..1fde0bf 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -317,6 +317,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
 	audit_log_task_info(ab, current);
 	audit_log_end(ab);
 
+	audit_log_ns_info(current);
+
 	iint->flags |= IMA_AUDITED;
 }
 
-- 
1.7.1