[PATCH 7.2 34/82] nfc: digital: clamp SENSF_RES length to the destination buffer

7.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Doruk Tan Ozturk <[email protected]>

commit 344a56d7c8e0f3cbaff0bcb1bcd95a1a1db24b16 upstream.

digital_in_recv_sensf_res() memcpy()s resp->len bytes from a remote
NFC-F device response into the NFC_SENSF_RES_MAXSIZE-byte target.sensf_res
field without an upper-bound check. A nearby malicious NFC-F device can
send an oversized SENSF_RES response to overflow the stack-local struct
nfc_target.

Clamp resp->len to NFC_SENSF_RES_MAXSIZE before the copy.

Found by 0sec automated security-research tooling (https://0sec.ai).

Fixes: 8c0695e4998d ("NFC Digital: Add NFC-F technology support")
Cc: [email protected]
Signed-off-by: Doruk Tan Ozturk <[email protected]>
Reviewed-by: Alexander Lobakin <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: David Heidelberg <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/nfc/digital_technology.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/nfc/digital_technology.c
+++ b/net/nfc/digital_technology.c
@@ -778,6 +778,8 @@ static void digital_in_recv_sensf_res(st
 
 	sensf_res = (struct digital_sensf_res *)resp->data;
 
+	resp->len = min_t(unsigned int, resp->len, NFC_SENSF_RES_MAXSIZE);
+
 	memcpy(target.sensf_res, sensf_res, resp->len);
 	target.sensf_res_len = resp->len;