[media] stv090x: add an extra protetion against buffer overflow

As pointed by smatch:
	drivers/media/dvb-frontends/stv090x.c:2787 stv090x_optimize_carloop() error: buffer overflow 'car_loop_apsk_low' 11 <= 13
	drivers/media/dvb-frontends/stv090x.c:2789 stv090x_optimize_carloop() error: buffer overflow 'car_loop_apsk_low' 11 <= 13
	drivers/media/dvb-frontends/stv090x.c:2791 stv090x_optimize_carloop() error: buffer overflow 'car_loop_apsk_low' 11 <= 13
	drivers/media/dvb-frontends/stv090x.c:2793 stv090x_optimize_carloop() error: buffer overflow 'car_loop_apsk_low' 11 <= 13
	drivers/media/dvb-frontends/stv090x.c:2795 stv090x_optimize_carloop() error: buffer overflow 'car_loop_apsk_low' 11 <= 13

The situation of a buffer overflow won't happen, in practice,
with the current values of car_loop table. Yet, the entire logic
that checks for those registration values is too complex. So,
better to add an explicit check, just in case someone changes
the car_loop tables causing a buffer overflow by mistake.

This also helps to remove several smatch warnings, with is good.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/dvb-frontends/stv090x.c b/drivers/media/dvb-frontends/stv090x.c
index bce9cc1072aa97981eae96a91048384ce9def288..0b2a934f53e58ee8413bd3040f39b221cc901d22 100644 (file)
--- a/drivers/media/dvb-frontends/stv090x.c
+++ b/drivers/media/dvb-frontends/stv090x.c
@@ -2783,6 +2783,12 @@ static u8 stv090x_optimize_carloop(struct stv090x_state *state, enum stv090x_mod
                                aclc = car_loop[i].crl_pilots_off_30;
                }
        } else { /* 16APSK and 32APSK */
+               /*
+                * This should never happen in practice, except if
+                * something is really wrong at the car_loop table.
+                */
+               if (i >= 11)
+                       i = 10;
                if (state->srate <= 3000000)
                        aclc = car_loop_apsk_low[i].crl_pilots_on_2;
                else if (state->srate <= 7000000)