staging: wfx: improve robustness of wfx_get_hw_rate()

Smatch complains:

    data_tx.c:37 wfx_get_hw_rate() warn: constraint '(struct ieee80211_supported_band)->bitrates' overflow 'band->bitrates' 0 <= abs_rl '0-127' user_rl '' required = '(struct ieee80211_supported_band)->n_bitrates'
    23          struct ieee80211_supported_band *band;
    24
    25          if (rate->idx < 0)
    26                  return -1;
    27          if (rate->flags & IEEE80211_TX_RC_MCS) {
    28                  if (rate->idx > 7) {
    29                          WARN(1, "wrong rate->idx value: %d", rate->idx);
    30                          return -1;
    31                  }
    32                  return rate->idx + 14;
    33          }
    34          // WFx only support 2GHz, else band information should be retrieved
    35          // from ieee80211_tx_info
    36          band = wdev->hw->wiphy->bands[NL80211_BAND_2GHZ];
    37          return band->bitrates[rate->idx].hw_value;

Add a simple check to make Smatch happy.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20201009171307.864608-9-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jérôme Pouiller 2020-10-09 19:13:07 +02:00 committed by Greg Kroah-Hartman
parent c9d4769639
commit 868fd970e1

View File

@ -31,6 +31,10 @@ static int wfx_get_hw_rate(struct wfx_dev *wdev,
}
return rate->idx + 14;
}
if (rate->idx >= band->n_bitrates) {
WARN(1, "wrong rate->idx value: %d", rate->idx);
return -1;
}
// WFx only support 2GHz, else band information should be retrieved
// from ieee80211_tx_info
band = wdev->hw->wiphy->bands[NL80211_BAND_2GHZ];