Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.16 12/37] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION | Date | Fri, 25 Mar 2022 16:14:22 +0100 |
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From: Jordy Zomer <jordy@pwning.systems>
commit 4fbcc1a4cb20fe26ad0225679c536c80f1648221 upstream.
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> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/nfc/st21nfca/se.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- a/drivers/nfc/st21nfca/se.c +++ b/drivers/nfc/st21nfca/se.c @@ -316,6 +316,11 @@ int st21nfca_connectivity_event_received 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 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);
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