Merge tag 'audit-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit updates from Paul Moore:
 "A small set of audit patches for v5.11 with four patches in total and
  only one of any real significance.

  Richard's patch to trigger accompanying records causes the kernel to
  emit additional related records when an audit event occurs; helping
  provide some much needed context to events in the audit log. It is
  also worth mentioning that this is a revised patch based on an earlier
  attempt that had to be reverted in the v5.8 time frame.

  Everything passes our test suite, and with no problems reported please
  merge this for v5.11"

* tag 'audit-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: replace atomic_add_return()
  audit: fix macros warnings
  audit: trigger accompanying records when no rules present
  audit: fix a kernel-doc markup

2 files changed, 18 insertions, 29 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 68cee3bc8cfe..1ffc2e059027 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -67,7 +67,7 @@
 #define AUDIT_DISABLED		-1
 #define AUDIT_UNINITIALIZED	0
 #define AUDIT_INITIALIZED	1
-static int	audit_initialized;
+static int	audit_initialized = AUDIT_UNINITIALIZED;
 
 u32		audit_enabled = AUDIT_OFF;
 bool		audit_ever_enabled = !!AUDIT_OFF;
@@ -523,7 +523,7 @@ static int auditd_set(struct pid *pid, u32 portid, struct net *net)
 }
 
 /**
- * kauditd_print_skb - Print the audit record to the ring buffer
+ * kauditd_printk_skb - Print the audit record to the ring buffer
  * @skb: audit record
  *
  * Whatever the reason, this packet may not make it to the auditd connection
@@ -1779,7 +1779,7 @@ unsigned int audit_serial(void)
 {
 	static atomic_t serial = ATOMIC_INIT(0);
 
-	return atomic_add_return(1, &serial);
+	return atomic_inc_return(&serial);
 }
 
 static inline void audit_get_stamp(struct audit_context *ctx,
@@ -1865,6 +1865,9 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
 	}
 
 	audit_get_stamp(ab->ctx, &t, &serial);
+	/* cancel dummy context to enable supporting records */
+	if (ctx)
+		ctx->dummy = 0;
 	audit_log_format(ab, "audit(%llu.%03lu:%u): ",
 			 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
 
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index c00aa5837965..ce8c9e2279ba 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -102,8 +102,6 @@ struct audit_aux_data {
 	int			type;
 };
 
-#define AUDIT_AUX_IPCPERM	0
-
 /* Number of target pids per aux struct. */
 #define AUDIT_AUX_PIDS	16
 
@@ -552,11 +550,11 @@ static int audit_filter_rules(struct task_struct *tsk,
 			break;
 
 		case AUDIT_EXIT:
-			if (ctx && ctx->return_valid)
+			if (ctx && ctx->return_valid != AUDITSC_INVALID)
 				result = audit_comparator(ctx->return_code, f->op, f->val);
 			break;
 		case AUDIT_SUCCESS:
-			if (ctx && ctx->return_valid) {
+			if (ctx && ctx->return_valid != AUDITSC_INVALID) {
 				if (f->val)
 					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
 				else
@@ -929,6 +927,8 @@ static inline struct audit_context *audit_alloc_context(enum audit_state state)
 	context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;
 	INIT_LIST_HEAD(&context->killed_trees);
 	INIT_LIST_HEAD(&context->names_list);
+	context->fds[0] = -1;
+	context->return_valid = AUDITSC_INVALID;
 	return context;
 }
 
@@ -1367,7 +1367,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
 			/* name was specified as a relative path and the
 			 * directory component is the cwd
 			 */
-			audit_log_d_path(ab, " name=", &context->pwd);
+			if (context->pwd.dentry && context->pwd.mnt)
+				audit_log_d_path(ab, " name=", &context->pwd);
+			else
+				audit_log_format(ab, " name=(null)");
 			break;
 		default:
 			/* log the name's directory component */
@@ -1435,9 +1438,6 @@ static void audit_log_proctitle(void)
 	struct audit_context *context = audit_context();
 	struct audit_buffer *ab;
 
-	if (!context || context->dummy)
-		return;
-
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE);
 	if (!ab)
 		return;	/* audit_panic or being filtered */
@@ -1487,7 +1487,7 @@ static void audit_log_exit(void)
 			 context->arch, context->major);
 	if (context->personality != PER_LINUX)
 		audit_log_format(ab, " per=%lx", context->personality);
-	if (context->return_valid)
+	if (context->return_valid != AUDITSC_INVALID)
 		audit_log_format(ab, " success=%s exit=%ld",
 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
 				 context->return_code);
@@ -1624,7 +1624,7 @@ void __audit_free(struct task_struct *tsk)
 	 * need to log via audit_log_exit().
 	 */
 	if (tsk == current && !context->dummy && context->in_syscall) {
-		context->return_valid = 0;
+		context->return_valid = AUDITSC_INVALID;
 		context->return_code = 0;
 
 		audit_filter_syscall(tsk, context,
@@ -1866,6 +1866,8 @@ static struct audit_names *audit_alloc_name(struct audit_context *context,
 	list_add_tail(&aname->list, &context->names_list);
 
 	context->name_count++;
+	if (!context->pwd.dentry)
+		get_fs_pwd(current->fs, &context->pwd);
 	return aname;
 }
 
@@ -1894,20 +1896,6 @@ __audit_reusename(const __user char *uptr)
 	return NULL;
 }
 
-inline void _audit_getcwd(struct audit_context *context)
-{
-	if (!context->pwd.dentry)
-		get_fs_pwd(current->fs, &context->pwd);
-}
-
-void __audit_getcwd(void)
-{
-	struct audit_context *context = audit_context();
-
-	if (context->in_syscall)
-		_audit_getcwd(context);
-}
-
 /**
  * __audit_getname - add a name to the list
  * @name: name to add
@@ -1931,8 +1919,6 @@ void __audit_getname(struct filename *name)
 	n->name_len = AUDIT_NAME_FULL;
 	name->aname = n;
 	name->refcnt++;
-
-	_audit_getcwd(context);
 }
 
 static inline int audit_copy_fcaps(struct audit_names *name,