diff --git a/security/keys/trusted-keys/trusted_dcp.c b/security/keys/trusted-keys/trusted_dcp.c
index 7b6eb655df0c..c078adebe190 100644
--- a/security/keys/trusted-keys/trusted_dcp.c
+++ b/security/keys/trusted-keys/trusted_dcp.c
@@ -69,7 +69,7 @@ static bool skip_zk_test;
 module_param_named(dcp_skip_zk_test, skip_zk_test, bool, 0);
 MODULE_PARM_DESC(dcp_skip_zk_test, "Don't test whether device keys are zero'ed");
 
-static unsigned int calc_blob_len(unsigned int payload_len)
+static size_t calc_blob_len(unsigned int payload_len)
 {
 	return sizeof(struct dcp_blob_fmt) + payload_len + DCP_BLOB_AUTHLEN;
 }
@@ -200,7 +200,8 @@ static int encrypt_blob_key(u8 *plain_key, u8 *encrypted_key)
 static int trusted_dcp_seal(struct trusted_key_payload *p, char *datablob)
 {
 	struct dcp_blob_fmt *b = (struct dcp_blob_fmt *)p->blob;
-	int blen, ret;
+	size_t blen;
+	int ret;
 	u8 *plain_blob_key;
 
 	blen = calc_blob_len(p->key_len);
@@ -242,7 +243,8 @@ static int trusted_dcp_seal(struct trusted_key_payload *p, char *datablob)
 static int trusted_dcp_unseal(struct trusted_key_payload *p, char *datablob)
 {
 	struct dcp_blob_fmt *b = (struct dcp_blob_fmt *)p->blob;
-	int blen, ret;
+	size_t blen;
+	int ret;
 	u8 *plain_blob_key = NULL;
 
 	if (b->fmt_version != DCP_BLOB_VERSION) {
@@ -253,9 +255,14 @@ static int trusted_dcp_unseal(struct trusted_key_payload *p, char *datablob)
 	}
 
 	p->key_len = le32_to_cpu(b->payload_len);
+	if (p->key_len < MIN_KEY_SIZE || p->key_len > MAX_KEY_SIZE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	blen = calc_blob_len(p->key_len);
 	if (blen != p->blob_len) {
-		pr_err("DCP blob has bad length: %i != %i\n", blen,
+		pr_err("DCP blob has bad length: %zu != %u\n", blen,
 		       p->blob_len);
 		ret = -EINVAL;
 		goto out;