[media] af9013: Don't accept invalid bandwidth

[ Upstream commit d7b76c91 ]

If userspace sends an invalid bandwidth, it should either return
EINVAL or switch to auto mode.

This driver will go past an array and program the hardware on a
wrong way if this happens.

Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

drivers/media/dvb-frontends/af9013.c

@@ -605,6 +605,10 @@ static int af9013_set_frontend(struct dvb_frontend *fe)
 			}
 		}
 
+		/* Return an error if can't find bandwidth or the right clock */
+		if (i == ARRAY_SIZE(coeff_lut))
+			return -EINVAL;
+
 		ret = af9013_wr_regs(state, 0xae00, coeff_lut[i].val,
 			sizeof(coeff_lut[i].val));
 	}