[PATCH] NFC: pn533: potential buffer overflow in pn533_target_found_type_a()

[Dan Carpenter]

Smatch doesn't trust information that comes from skb->data.  It
complains that "nfc_tgt->nfcid1_len" is a u8 so it could be up to 255
bytes, but the destination buffer is only 10 bytes large.

Fixes: c3b1e1e8a76f ("NFC: Export NFCID1 from pn533")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
 drivers/nfc/pn533/pn533.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index a0cc1cc45292..9f9bbf912687 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -724,6 +724,8 @@ static int pn533_target_found_type_a(struct nfc_target 
*nfc_tgt, u8 *tgt_data,
        nfc_tgt->sens_res = be16_to_cpu(tgt_type_a->sens_res);
        nfc_tgt->sel_res = tgt_type_a->sel_res;
        nfc_tgt->nfcid1_len = tgt_type_a->nfcid_len;
+       if (nfc_tgt->nfcid1_len > sizeof(nfc_tgt->nfcid1))
+               return -EINVAL;
        memcpy(nfc_tgt->nfcid1, tgt_type_a->nfcid_data, nfc_tgt->nfcid1_len);
 
        return 0;
-- 
2.17.1