On Mon, Jun 6, 2022 at 7:57 PM Martin Faltesek mfaltesek@google.com wrote:

Error paths do not free previously allocated memory. Add devm_kfree() to those failure paths.

Fixes: 26fc6c7f02cb ("NFC: st21nfca: Add HCI transaction event support") Fixes: 4fbcc1a4cb20 ("nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION") Cc: stable@vger.kernel.org Signed-off-by: Martin Faltesek mfaltesek@google.com

Reviewed-by: Guenter Roeck groeck@chromium.org

---

drivers/nfc/st21nfca/se.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c index 9645777f2544..8e1113ce139b 100644 --- a/drivers/nfc/st21nfca/se.c +++ b/drivers/nfc/st21nfca/se.c @@ -326,22 +326,29 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host, transaction->aid_len = skb->data[1];

            /* Checking if the length of the AID is valid */

•           if (transaction->aid_len > sizeof(transaction->aid))
  

•           if (transaction->aid_len > sizeof(transaction->aid)) {
  

•                   devm_kfree(dev, transaction);
                    return -EINVAL;
  

•           }
  
            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)
  

•               NFC_EVT_TRANSACTION_PARAMS_TAG) {
  

•                   devm_kfree(dev, transaction);
                    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)))
  

•           if (transaction->params_len > ((skb->len - 2) -
  

•               sizeof(struct nfc_evt_transaction))) {
  

•                   devm_kfree(dev, transaction);
                    return -EINVAL;
  

•           }
  
            memcpy(transaction->params, skb->data +
                   transaction->aid_len + 4, transaction->params_len);
  

-- 2.36.1.255.ge46751e96f-goog