RE: [PATCH v2] iwlegacy: 4965: fix possible out-of-bounds access in il4965_tx_cmd_build_rate()

[Ping-Ke Shih <pkshih@realtek.com>]

Alexei Safin <a.safin@rosa.ru> wrote:
> 
> Prevent out-of-bounds access in il4965_tx_cmd_build_rate() by rejecting
> rate_idx values greater than or equal to RATE_COUNT_LEGACY.
> 
> Use a correct bounds check to avoid accessing il_rates[] with
> an invalid index. The previous comparison allowed rate_idx to become
> equal to RATE_COUNT_LEGACY, which exceeds the array limit.
> 
> Replace the check 'rate_idx > RATE_COUNT_LEGACY' with
> 'rate_idx >= RATE_COUNT_LEGACY' to ensure memory safety.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 7ac9a364c172 ("iwlegacy: move under intel directory")

The Fixes is obviously wrong. It just moved the code. 

> Signed-off-by: Alexei Safin <a.safin@rosa.ru>
> ---
> v2: change reciepent
>  drivers/net/wireless/intel/iwlegacy/4965-mac.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> index 78dee8ccfebf..f60d9b9798c1 100644
> --- a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> +++ b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> @@ -1572,7 +1572,7 @@ il4965_tx_cmd_build_rate(struct il_priv *il,
>          */
>         rate_idx = info->control.rates[0].idx;
>         if ((info->control.rates[0].flags & IEEE80211_TX_RC_MCS) || rate_idx < 0
> -           || rate_idx > RATE_COUNT_LEGACY)
> +           || rate_idx >= RATE_COUNT_LEGACY)
>                 rate_idx = rate_lowest_index(&il->bands[info->band], sta);
>         /* For 5 GHZ band, remap mac80211 rate indices into driver indices */
>         if (info->band == NL80211_BAND_5GHZ)
> --
> 2.39.5 (Apple Git-154)
>