From: Jordy Zomer Date: Tue, 11 Jan 2022 16:44:51 +0000 (+0100) Subject: nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4fbcc1a4cb20fe26ad0225679c536c80f1648221;p=linux.git nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION It appears that there are some buffer overflows in EVT_TRANSACTION. This happens because the length parameters that are passed to memcpy come directly from skb->data and are not guarded in any way. Signed-off-by: Jordy Zomer Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller --- diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c index a43fc4117fa57..c922f10d0d7b9 100644 --- a/drivers/nfc/st21nfca/se.c +++ b/drivers/nfc/st21nfca/se.c @@ -316,6 +316,11 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host, return -ENOMEM; transaction->aid_len = skb->data[1]; + + /* Checking if the length of the AID is valid */ + if (transaction->aid_len > sizeof(transaction->aid)) + return -EINVAL; + memcpy(transaction->aid, &skb->data[2], transaction->aid_len); @@ -325,6 +330,11 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host, return -EPROTO; transaction->params_len = skb->data[transaction->aid_len + 3]; + + /* Total size is allocated (skb->len - 2) minus fixed array members */ + if (transaction->params_len > ((skb->len - 2) - sizeof(struct nfc_evt_transaction))) + return -EINVAL; + memcpy(transaction->params, skb->data + transaction->aid_len + 4, transaction->params_len);