[PATCH v3] nfc: st-nci: Fix potential buffer overflows in EVT_TRANSACTION
From: Jordy Zomer <hidden>
Date: 2022-01-11 16:45:56
Also in:
lkml
Subsystem:
nfc subsystem, the rest · Maintainers:
David Heidelberg, Linus Torvalds
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 <redacted> --- 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