diff --git a/user-src/ipc-linux.h b/user-src/ipc-linux.h
index 42fc3cd..eda7e68 100644
--- a/user-src/ipc-linux.h
+++ b/user-src/ipc-linux.h
@@ -540,20 +540,24 @@ static int parse_privkey(const struct nlattr *attr, void *data)
 
 	switch (mnl_attr_get_type(attr)) {
 	case WGDEVICE_A_PRIVATE_KEY:
-		*privkey->privkey_len = mnl_attr_get_payload_len(attr);
-		*privkey->privkey = malloc(*privkey->privkey_len);
+		if (mnl_attr_get_payload_len(attr) != WG_PRIVATE_KEY_LEN)
+			return MNL_CB_ERROR;
+		*privkey->privkey_len = WG_PRIVATE_KEY_LEN;
+		*privkey->privkey = malloc(WG_PRIVATE_KEY_LEN);
 		if (! *privkey->privkey)
 			return MNL_CB_ERROR;
-		memcpy(*privkey->privkey, mnl_attr_get_payload(attr), *privkey->privkey_len);
+		memcpy(*privkey->privkey, mnl_attr_get_payload(attr), WG_PRIVATE_KEY_LEN);
 		break;
 	case WGDEVICE_A_PUBLIC_KEY:
 		if (! privkey->pubkey)
 			return MNL_CB_OK;
-		*privkey->pubkey_len = mnl_attr_get_payload_len(attr);
-		*privkey->pubkey = malloc(*privkey->pubkey_len);
+		if (mnl_attr_get_payload_len(attr) != WG_PUBLIC_KEY_LEN)
+			return MNL_CB_ERROR;
+		*privkey->pubkey_len = WG_PUBLIC_KEY_LEN;
+		*privkey->pubkey = malloc(WG_PUBLIC_KEY_LEN);
 		if (! *privkey->pubkey)
 			return MNL_CB_ERROR;
-		memcpy(*privkey->pubkey, mnl_attr_get_payload(attr), *privkey->pubkey_len);
+		memcpy(*privkey->pubkey, mnl_attr_get_payload(attr), WG_PUBLIC_KEY_LEN);
 		break;
 	}
 
@@ -605,8 +609,10 @@ static int kernel_generate_privkey(uint8_t **privkey, size_t *privkey_len, uint8
 	}
 
 out:
-	if (nlg)
+	if (nlg) {
 		mnlg_socket_close(nlg);
+		nlg = NULL;
+	}
 	if (ret) {
 		if (*privkey) {
 			memzero_explicit(*privkey, *privkey_len);
@@ -641,11 +647,13 @@ static int parse_pubkey(const struct nlattr *attr, void *data)
 	case WGDEVICE_A_PUBLIC_KEY:
 		if (! pubkey->pubkey)
 			return MNL_CB_OK;
-		*pubkey->pubkey_len = mnl_attr_get_payload_len(attr);
-		*pubkey->pubkey = malloc(*pubkey->pubkey_len);
+		if (mnl_attr_get_payload_len(attr) != WG_PUBLIC_KEY_LEN)
+			return MNL_CB_ERROR;
+		*pubkey->pubkey_len = WG_PUBLIC_KEY_LEN;
+		*pubkey->pubkey = malloc(WG_PUBLIC_KEY_LEN);
 		if (! *pubkey->pubkey)
 			return MNL_CB_ERROR;
-		memcpy(*pubkey->pubkey, mnl_attr_get_payload(attr), *pubkey->pubkey_len);
+		memcpy(*pubkey->pubkey, mnl_attr_get_payload(attr), WG_PUBLIC_KEY_LEN);
 		break;
 	}
 
@@ -691,8 +699,10 @@ static int kernel_derive_pubkey(const uint8_t *privkey, size_t privkey_len, uint
 	}
 
 out:
-	if (nlg)
+	if (nlg) {
 		mnlg_socket_close(nlg);
+		nlg = NULL;
+	}
 	if (ret) {
 		if (*pubkey) {
 			free(*pubkey);
@@ -717,11 +727,13 @@ static int parse_psk(const struct nlattr *attr, void *data)
 
 	switch (mnl_attr_get_type(attr)) {
 	case WGDEVICE_A_PRESHARED_KEY:
-		*psk->psk_len = mnl_attr_get_payload_len(attr);
-		*psk->psk = malloc(*psk->psk_len);
+		if (mnl_attr_get_payload_len(attr) != WG_SYMMETRIC_KEY_LEN)
+			return MNL_CB_ERROR;
+		*psk->psk_len = WG_SYMMETRIC_KEY_LEN;
+		*psk->psk = malloc(WG_SYMMETRIC_KEY_LEN);
 		if (! *psk->psk)
 			return MNL_CB_ERROR;
-		memcpy(*psk->psk, mnl_attr_get_payload(attr), *psk->psk_len);
+		memcpy(*psk->psk, mnl_attr_get_payload(attr), WG_SYMMETRIC_KEY_LEN);
 		break;
 	}
 
@@ -766,8 +778,10 @@ static int kernel_generate_psk(uint8_t **psk, size_t *psk_len)
 	}
 
 out:
-	if (nlg)
+	if (nlg) {
 		mnlg_socket_close(nlg);
+		nlg = NULL;
+	}
 	if (ret) {
 		if (*psk) {
 			memzero_explicit(*psk, *psk_len);