Hi
On Thu, Apr 24, 2025 at 09:52:44PM +0300, Alexei Safin 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.
Thanks for the patch, however I think it's not correct.
The definitions are:
enum {
RATE_1M_IDX = 0,
...
RATE_54M_INDEX,
RATE_60M_INDEX,
RATE_COUNT
RATE_COUNT_LEGACY = RATE_COUNT - 1, /* Excluding 60M */
}
extern const struct il_rate_info il_rates[RATE_COUNT];
> 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")
> Signed-off-by: Alexei Safin <a.safin@xxxxxxx>
> ---
> 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);
.. so looks the check is fine already and changing it will induce a bug
for RATE_54M_INDEX.
Regards
Stanislaw
> /* For 5 GHZ band, remap mac80211 rate indices into driver indices */
> if (info->band == NL80211_BAND_5GHZ)
> --
> 2.39.5 (Apple Git-154)
>
