From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 2 Apr 2021 11:44:42 +0000 (+0300)
Subject: nfc: pn533: prevent potential memory corruption
X-Git-Tag: v5.10.37~145
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=db574a60c48236addd86113da86f1343078ee4fc;p=thirdparty%2Fkernel%2Fstable.git

nfc: pn533: prevent potential memory corruption

[ Upstream commit ca4d4c34ae9aa5c3c0da76662c5e549d2fc0cc86 ]

If the "type_a->nfcid_len" is too large then it would lead to memory
corruption in pn533_target_found_type_a() when we do:

	memcpy(nfc_tgt->nfcid1, tgt_type_a->nfcid_data, nfc_tgt->nfcid1_len);

Fixes: c3b1e1e8a76f ("NFC: Export NFCID1 from pn533")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index f7464bd6d57cb..18e3435ab8f33 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -706,6 +706,9 @@ static bool pn533_target_type_a_is_valid(struct pn533_target_type_a *type_a,
 	if (PN533_TYPE_A_SEL_CASCADE(type_a->sel_res) != 0)
 		return false;
 
+	if (type_a->nfcid_len > NFC_NFCID1_MAXSIZE)
+		return false;
+
 	return true;
 }