Implement AUDIT_CRYPTO_KEY_VALUEncr-audit

1 files changed, 102 insertions, 14 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index fcd6d2e7ab9..30853986ab9 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -81,6 +81,9 @@
 /* no execve audit message should be longer than this (userspace limits) */
 #define MAX_EXECVE_AUDIT_LEN 7500
 
+/* Number of public key values that can be audited */
+#define AUDIT_MAX_CRYPTO_KEY_VALUES 4
+
 /* number of audit rules */
 int audit_n_rules;
 
@@ -158,9 +161,14 @@ struct audit_aux_data_capset {
 	struct audit_cap_data	cap;
 };
 
-struct audit_crypto_op {
+#define AUDIT_CRYPTO_OP_KEY_VALUE -1
+struct audit_crypto_header {
 	struct list_head list;
-	int op;
+	int op;		       /* AUDIT_CRYPTO_OP_KEY_VALUE for key values */
+};
+
+struct audit_crypto_op {
+	struct audit_crypto_header hdr;
 	int context;
 	int session;
 	const char *operation;
@@ -173,6 +181,12 @@ struct audit_crypto_op {
 	size_t key2_id_size;
 };
 
+struct audit_crypto_values {
+	struct audit_crypto_header hdr;
+	size_t num_values;
+	struct audit_crypto_value values[AUDIT_MAX_CRYPTO_KEY_VALUES];
+};
+
 struct audit_tree_refs {
 	struct audit_tree_refs *next;
 	struct audit_chunk *c[31];
@@ -650,11 +664,13 @@ static int audit_filter_rules(struct task_struct *tsk,
 			result = audit_match_filetype(ctx, f->val);
 			break;
 		case AUDIT_CRYPTO_OP: {
-			struct audit_crypto_op *ax;
+			struct audit_crypto_header *ax;
 
 			if (!ctx)
 				break;
 			list_for_each_entry(ax, &ctx->crypto, list) {
+				if (ax->op == AUDIT_CRYPTO_OP_KEY_VALUE)
+					continue;
 				result = audit_comparator(ax->op, f->op,
 							  f->val);
 				if (result)
@@ -854,10 +870,23 @@ static inline void audit_free_names(struct audit_context *context)
 	context->pwd.mnt = NULL;
 }
 
+static void audit_free_crypto_op(struct audit_crypto_header *crypto)
+{
+	if (crypto->op == AUDIT_CRYPTO_OP_KEY_VALUE) {
+		struct audit_crypto_values *val;
+		size_t i;
+
+		val = (struct audit_crypto_values *)crypto;
+		for (i = 0; i < val->num_values; i++)
+			kfree(val->values[i].value);
+	}
+	kfree(crypto);
+}
+
 static inline void audit_free_aux(struct audit_context *context)
 {
 	struct audit_aux_data *aux;
-	struct audit_crypto_op *crypto, *tmp;
+	struct audit_crypto_header *crypto, *tmp;
 
 	while ((aux = context->aux)) {
 		context->aux = aux->next;
@@ -869,7 +898,7 @@ static inline void audit_free_aux(struct audit_context *context)
 	}
 	list_for_each_entry_safe(crypto, tmp, &context->crypto, list) {
 		list_del(&crypto->list);
-		kfree(crypto);
+		audit_free_crypto_op(crypto);
 	}
 }
 
@@ -1347,7 +1376,7 @@ static void show_special(struct audit_context *context, int *call_panic)
 }
 
 static void log_crypto_op(struct audit_context *context,
-			  struct audit_crypto_op *crypto)
+			  const struct audit_crypto_header *header)
 {
 	static const char *const ops[] = {
 		[AUDIT_CRYPTO_OP_CONTEXT_NEW] = "context_new",
@@ -1365,15 +1394,17 @@ static void log_crypto_op(struct audit_context *context,
 		[AUDIT_CRYPTO_OP_KEY_GET_INFO] = "key_get_info",
 	};
 
+	const struct audit_crypto_op *crypto;
 	struct audit_buffer *ab;
 
+	crypto = (struct audit_crypto_op *)header;
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CRYPTO_USERSPACE_OP);
 	if (!ab)
 		return;
-	if (crypto->op < ARRAY_SIZE(ops) && ops[crypto->op] != NULL)
-		audit_log_format(ab, "crypto_op=%s", ops[crypto->op]);
+	if (header->op < ARRAY_SIZE(ops) && ops[header->op] != NULL)
+		audit_log_format(ab, "crypto_op=%s", ops[header->op]);
 	else
-		audit_log_format(ab, "crypto_op=%d", crypto->op);
+		audit_log_format(ab, "crypto_op=%d", header->op);
 	audit_log_format(ab, " ctx=%d", crypto->context);
 	if (crypto->session != -1)
 		audit_log_format(ab, " session=%d", crypto->session);
@@ -1404,13 +1435,31 @@ static void log_crypto_op(struct audit_context *context,
 	audit_log_end(ab);
 }
 
+static void log_crypto_values(struct audit_context *context,
+			      const struct audit_crypto_header *header)
+{
+	struct audit_buffer *ab;
+	const struct audit_crypto_values *crypto;
+	const struct audit_crypto_value *v;
+
+	crypto = (struct audit_crypto_values *)header;
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CRYPTO_KEY_VALUE);
+	if (!ab)
+		return;
+	for (v = crypto->values; v < crypto->values + crypto->num_values; v++) {
+		audit_log_format(ab, " key_value_%c=", v->name);
+		audit_log_n_hex(ab, v->value, v->value_size);
+	}
+	audit_log_end(ab);
+}
+
 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 {
 	const struct cred *cred;
 	int i, call_panic = 0;
 	struct audit_buffer *ab;
 	struct audit_aux_data *aux;
-	struct audit_crypto_op *crypto;
+	struct audit_crypto_header *crypto;
 	const char *tty;
 
 	/* tsk == current */
@@ -1537,8 +1586,12 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 				call_panic = 1;
 	}
 
-	list_for_each_entry(crypto, &context->crypto, list)
-		log_crypto_op(context, crypto);
+	list_for_each_entry(crypto, &context->crypto, list) {
+		if (crypto->op != AUDIT_CRYPTO_OP_KEY_VALUE)
+			log_crypto_op(context, crypto);
+		else
+			log_crypto_values(context, crypto);
+	}
 
 	if (context->target_pid &&
 	    audit_log_pid_context(context, context->target_pid,
@@ -2609,7 +2662,7 @@ int __audit_log_crypto_op(int op, int context, int session,
 	if (!ax)
 		return -ENOMEM;
 
-	ax->op = op;
+	ax->hdr.op = op;
 	ax->context = context;
 	ax->session = session;
 	ax->operation = operation;
@@ -2626,12 +2679,47 @@ int __audit_log_crypto_op(int op, int context, int session,
 		memcpy(ax->key2_id, key2_id, ax->key2_id_size);
 	} else
 		ax->key2_id_size = 0;
-	list_add_tail(&ax->list, &ctx->crypto);
+	list_add_tail(&ax->hdr.list, &ctx->crypto);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__audit_log_crypto_op);
 
 /**
+ * __audit_log_crypto_op - store information about values of crypto keys
+ * @values: individual byte arrays describing the key.  The "value" members
+ * must be allocated using kmalloc(), this function will take care of freeing
+ * them.
+ * @num_values: number of elements in @values
+ */
+void __audit_log_crypto_values(const struct audit_crypto_value *values,
+			       size_t num_values)
+{
+	struct audit_crypto_values *ax;
+	struct audit_context *ctx = current->audit_context;
+	size_t i;
+
+	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
+	if (!ax)
+		goto free_values;
+
+	ax->hdr.op = AUDIT_CRYPTO_OP_KEY_VALUE;
+	BUG_ON(num_values > ARRAY_SIZE(ax->values));
+	ax->num_values = num_values;
+	for (i = 0; i < num_values; i++) {
+		ax->values[i].name = values[i].name;
+		ax->values[i].value = values[i].value;
+		ax->values[i].value_size = values[i].value_size;
+	}
+	list_add_tail(&ax->hdr.list, &ctx->crypto);
+	return;
+
+free_values:
+	for (i = 0; i < num_values; i++)
+		kfree(values[i].value);
+}
+EXPORT_SYMBOL_GPL(__audit_log_crypto_values);
+
+/**
  * audit_core_dumps - record information about processes that end abnormally
  * @signr: signal value
  *