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ANDROID: NFC: st21nfca: Fix memory OOB and leak issues in connectivity events handler

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Overflow on memcpy is possible in kernel driver for st21nfca's
NFC HCI layer when handling connectivity events if aid_len or
params_len are bigger than the buffer size.
Memory leak is possible when parameter tag is invalid.

Bug: 62679581

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
This commit is contained in:
Suren Baghdasaryan 2017-08-17 13:58:40 -07:00 committed by Amit Pundir
parent 4818d4b11d
commit 8b6701269a
1 changed files with 17 additions and 7 deletions
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24
drivers/nfc/st21nfca/se.c
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@ -322,23 +322,33 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
* AID 81 5 to 16
* PARAMETERS 82 0 to 255
*/
if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
if (skb->len < NFC_MIN_AID_LENGTH + 2 ||
skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
return -EPROTO;
/*
* Buffer should have enough space for at least
* two tag fields + two length fields + aid_len (skb->data[1])
*/
if (skb->len < skb->data[1] + 4)
return -EPROTO;
transaction = (struct nfc_evt_transaction *)devm_kzalloc(dev,
skb->len - 2, GFP_KERNEL);
transaction->aid_len = skb->data[1];
memcpy(transaction->aid, &skb->data[2],
transaction->aid_len);
/* Check next byte is PARAMETERS tag (82) */
if (skb->data[transaction->aid_len + 2] !=
NFC_EVT_TRANSACTION_PARAMS_TAG)
return -EPROTO;
transaction->params_len = skb->data[transaction->aid_len + 3];
/* Check next byte is PARAMETERS tag (82) and the length field */
if (skb->data[transaction->aid_len + 2] !=
NFC_EVT_TRANSACTION_PARAMS_TAG ||
skb->len < transaction->aid_len + transaction->params_len + 4) {
devm_kfree(dev, transaction);
return -EPROTO;
}
memcpy(transaction->params, skb->data +
transaction->aid_len + 4, transaction->params_len);