[PATCH 4.9 162/167] nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling

Greg Kroah-Hartman
2022-06-13T10:34:45Z

From: Martin Faltesek <mfaltesek@google.com>

commit 996419e0594abb311fb958553809f24f38e7abbe upstream.

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>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/nfc/st21nfca/se.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/nfc/st21nfca/se.c
+++ b/drivers/nfc/st21nfca/se.c
@@ -332,22 +332,29 @@ int st21nfca_connectivity_event_received
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);