[PATCH 4.9 142/240] nfc: pn533: prevent potential memory corruption

Greg Kroah-Hartman
2021-05-20T11:16:10Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ 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>
---
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 d9c55830b2b2..6c495664d2cb 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -678,6 +678,9 @@ 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