diff options
| -rw-r--r-- | drivers/nfc/st-nci/se.c | 51 |
1 files changed, 36 insertions, 15 deletions
diff --git a/drivers/nfc/st-nci/se.c b/drivers/nfc/st-nci/se.c index fc59916ae5ae..ec87dd21e054 100644 --- a/drivers/nfc/st-nci/se.c +++ b/drivers/nfc/st-nci/se.c @@ -312,6 +312,8 @@ static int st_nci_hci_connectivity_event_received(struct nci_dev *ndev, int r = 0; struct device *dev = &ndev->nfc_dev->dev; struct nfc_evt_transaction *transaction; + u32 aid_len; + u8 params_len; pr_debug("connectivity gate event: %x\n", event); @@ -325,28 +327,47 @@ static int st_nci_hci_connectivity_event_received(struct nci_dev *ndev, * Description Tag Length * AID 81 5 to 16 * PARAMETERS 82 0 to 255 + * + * The key differences are aid storage length is variably sized + * in the packet, but fixed in nfc_evt_transaction, and that + * the aid_len is u8 in the packet, but u32 in the structure, + * and the tags in the packet are not included in + * nfc_evt_transaction. + * + * size(b): 1 1 5-16 1 1 0-255 + * offset: 0 1 2 aid_len + 2 aid_len + 3 aid_len + 4 + * mem name: aid_tag(M) aid_len aid params_tag(M) params_len params + * example: 0x81 5-16 X 0x82 0-255 X */ - if (skb->len < NFC_MIN_AID_LENGTH + 2 || - skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG) + if (skb->len < 2 || skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG) return -EPROTO; - transaction = devm_kzalloc(dev, skb->len - 2, GFP_KERNEL); - if (!transaction) - return -ENOMEM; + aid_len = skb->data[1]; - transaction->aid_len = skb->data[1]; - memcpy(transaction->aid, &skb->data[2], transaction->aid_len); + if (skb->len < aid_len + 4 || + aid_len > sizeof(transaction->aid)) + return -EPROTO; - /* Check next byte is PARAMETERS tag (82) */ - if (skb->data[transaction->aid_len + 2] != - NFC_EVT_TRANSACTION_PARAMS_TAG) { - devm_kfree(dev, transaction); + params_len = skb->data[aid_len + 3]; + + /* Verify PARAMETERS tag is (82), and final check that there is + * enough space in the packet to read everything. + */ + if (skb->data[aid_len + 2] != NFC_EVT_TRANSACTION_PARAMS_TAG || + skb->len < aid_len + 4 + params_len) return -EPROTO; - } - transaction->params_len = skb->data[transaction->aid_len + 3]; - memcpy(transaction->params, skb->data + - transaction->aid_len + 4, transaction->params_len); + transaction = devm_kzalloc(dev, sizeof(*transaction) + + params_len, GFP_KERNEL); + if (!transaction) + return -ENOMEM; + + transaction->aid_len = aid_len; + transaction->params_len = params_len; + + memcpy(transaction->aid, &skb->data[2], aid_len); + memcpy(transaction->params, &skb->data[aid_len + 4], + params_len); r = nfc_se_transaction(ndev->nfc_dev, host, transaction); break; |