From 996419e0594abb311fb958553809f24f38e7abbe Mon Sep 17 00:00:00 2001
From: Martin Faltesek <mfaltesek@google.com>
Date: Mon, 6 Jun 2022 21:57:28 -0500
Subject: [PATCH] nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling
Git-commit: 996419e0594abb311fb958553809f24f38e7abbe
Patch-mainline: v5.19-rc2
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 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);
-- 
2.35.3