diff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c index 9eeb862825c5..85c3ff2b78cd 100644 --- a/net/nfc/nci/rsp.c +++ b/net/nfc/nci/rsp.c @@ -50,11 +50,27 @@ static u8 nci_core_init_rsp_packet_v1(struct nci_dev *ndev, const struct nci_core_init_rsp_1 *rsp_1 = (void *)skb->data; const struct nci_core_init_rsp_2 *rsp_2; + /* Ensure that the status field can be accessed. */ + if (skb_headlen(skb) < 1) + return NCI_STATUS_SYNTAX_ERROR; + pr_debug("status 0x%x\n", rsp_1->status); if (rsp_1->status != NCI_STATUS_OK) return rsp_1->status; + /* Success response must contain the full fixed-size header */ + if (skb_headlen(skb) < sizeof(*rsp_1)) + return NCI_STATUS_SYNTAX_ERROR; + + /* Ensure the variable-length rf_interfaces array and trailing + * rsp_2 structure are fully contained within the skb. + */ + if (skb_headlen(skb) < sizeof(*rsp_1) + + rsp_1->num_supported_rf_interfaces + + sizeof(*rsp_2)) + return NCI_STATUS_SYNTAX_ERROR; + ndev->nfcc_features = __le32_to_cpu(rsp_1->nfcc_features); ndev->num_supported_rf_interfaces = rsp_1->num_supported_rf_interfaces; @@ -87,15 +103,25 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev, const struct sk_buff *skb) { const struct nci_core_init_rsp_nci_ver2 *rsp = (void *)skb->data; - const u8 *supported_rf_interface = rsp->supported_rf_interfaces; + const u8 *supported_rf_interface; u8 rf_interface_idx = 0; u8 rf_extension_cnt = 0; + /* Ensure that the status field can be accessed. */ + if (skb_headlen(skb) < 1) + return NCI_STATUS_SYNTAX_ERROR; + pr_debug("status %x\n", rsp->status); if (rsp->status != NCI_STATUS_OK) return rsp->status; + /* Success response must contain the full fixed-size header */ + if (skb_headlen(skb) < sizeof(*rsp)) + return NCI_STATUS_SYNTAX_ERROR; + + supported_rf_interface = rsp->supported_rf_interfaces; + ndev->nfcc_features = __le32_to_cpu(rsp->nfcc_features); ndev->num_supported_rf_interfaces = rsp->num_supported_rf_interfaces; @@ -104,13 +130,22 @@ static u8 nci_core_init_rsp_packet_v2(struct nci_dev *ndev, NCI_MAX_SUPPORTED_RF_INTERFACES); while (rf_interface_idx < ndev->num_supported_rf_interfaces) { - ndev->supported_rf_interfaces[rf_interface_idx++] = *supported_rf_interface++; + /* Each entry: [rf_interface_type (1B)] [ext_count (1B)] [ext...] */ + if (supported_rf_interface + 2 > skb_tail_pointer(skb)) + break; + ndev->supported_rf_interfaces[rf_interface_idx] = *supported_rf_interface++; - /* skip rf extension parameters */ rf_extension_cnt = *supported_rf_interface++; + if (supported_rf_interface + rf_extension_cnt > skb_tail_pointer(skb)) + break; + + /* Only count the entry after full validation */ + rf_interface_idx++; supported_rf_interface += rf_extension_cnt; } + ndev->num_supported_rf_interfaces = rf_interface_idx; + ndev->max_logical_connections = rsp->max_logical_connections; ndev->max_routing_table_size = __le16_to_cpu(rsp->max_routing_table_size);