crypto: ecrdsa - fix unknown OID check in ecrdsa_param_curve

[ Upstream commit 2d7b2cf ]

The ->curve_oid check in ecrdsa_param_curve() rejects the valid enum
value 0 (OID_id_dsa_with_sha1), but look_up_OID() returns OID__NR on
lookup failure. Compare ->curve_oid with OID__NR instead to ensure that
only unknown OIDs return -EINVAL.

Fixes: 0d7a786 ("crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: toblux

crypto/ecrdsa.c

@@ -153,7 +153,7 @@ int ecrdsa_param_curve(void *context, size_t hdrlen, unsigned char tag,
 	struct ecrdsa_ctx *ctx = context;
 
 	ctx->curve_oid = look_up_OID(value, vlen);
-	if (!ctx->curve_oid)
+	if (ctx->curve_oid == OID__NR)
 		return -EINVAL;
 	ctx->curve = get_curve_by_oid(ctx->curve_oid);
 	return 0;