[PATCH 4.14 202/323] nfc: pn533: prevent potential memory corruption

[Greg Kroah-Hartman]

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/nfc/pn533/pn533.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index c05cb637ba92..e3026e20f169 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -692,6 +692,9 @@ 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;
 }
 
-- 
2.30.2