The "rate_index" is only used as an index into the phist_data->rx_rate[]
array in the mwifiex_hist_data_set() function. That array has
MWIFIEX_MAX_AC_RX_RATES (74) elements and it's used to generate some
debugfs information. The "rate_index" variable comes from the network
skb->data[] and it is a u8 so it's in the 0-255 range. We need to cap
it to prevent an array overflow.
Fixes: cbf6e05527a7 ("mwifiex: add rx histogram statistics support") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>