Messages in this thread Patch in this message | | | From | Jordy Zomer <> | Subject | [PATCH v3] nfc: st-nci: Fix potential buffer overflows in EVT_TRANSACTION | Date | Tue, 11 Jan 2022 17:45:43 +0100 |
| |
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 <jordy@pwning.systems> --- drivers/nfc/st-nci/se.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/nfc/st-nci/se.c b/drivers/nfc/st-nci/se.c index 7764b1a4c3cf..cdb59ddff4e8 100644 --- a/drivers/nfc/st-nci/se.c +++ b/drivers/nfc/st-nci/se.c @@ -335,6 +335,11 @@ static int st_nci_hci_connectivity_event_received(struct nci_dev *ndev, 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); /* Check next byte is PARAMETERS tag (82) */ @@ -343,6 +348,11 @@ static int st_nci_hci_connectivity_event_received(struct nci_dev *ndev, 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); -- 2.27.0
| |