[PATCH] ieee802154: mcr20a: read out of bounds in mcr20a_set_channel()

[Dan Carpenter]

The "channel" variable can be any u8 value.  We need to make sure we
don't read outside of the PLL_INT[] or PLL_FRAC[] arrays.

Fixes: 8c6ad9cc5157 ("ieee802154: Add NXP MCR20A IEEE 802.15.4 transceiver 
driver")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
This patch is obviously harmless, but it's from static analysis.  I'm
pretty sure this is required, but I can't swear.

diff --git a/drivers/net/ieee802154/mcr20a.c b/drivers/net/ieee802154/mcr20a.c
index e428277781ac..4f41d1d3588e 100644
--- a/drivers/net/ieee802154/mcr20a.c
+++ b/drivers/net/ieee802154/mcr20a.c
@@ -512,6 +512,9 @@ mcr20a_set_channel(struct ieee802154_hw *hw, u8 page, u8 
channel)
 
        dev_dbg(printdev(lp), "%s\n", __func__);
 
+       if (channel < 11 || channel - 11 >= ARRAY_SIZE(PLL_INT))
+               return -EINVAL;
+
        /* freqency = ((PLL_INT+64) + (PLL_FRAC/65536)) * 32 MHz */
        ret = regmap_write(lp->regmap_dar, DAR_PLL_INT0, PLL_INT[channel - 11]);
        if (ret)