From: Jordy Zomer jordy@pwning.systems

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.

Link: https://lore.kernel.org/all/20220111164451.3232987-1-jordy@pwning.systems/#t Fixes: 26fc6c7f02cb ("NFC: st21nfca: Add HCI transaction event support") Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Jordy Zomer jordy@pwning.systems Reviewed-by: Krzysztof Kozlowski krzysztof.kozlowski@canonical.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Denis Efremov denis.e.efremov@oracle.com --- CVE-2022-26490 was assigned to this patch. It looks like it's not in the stable trees yet. I only added Link:/Fixes:/Cc: stable... to the commit's message.

drivers/nfc/st21nfca/se.c | 10 ++++++++++ 1 file changed, 10 insertions(+)

diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c index a43fc4117fa5..c922f10d0d7b 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);