Hi Stefan,
Thanks for the investigation & fix. I've changed the fix to use
cfg80211_sinfo_release_content(), take care of the error path in
cfg80211_wext_giwrate() and added a Fixes tag :-)
Applied with those changes.
johannes
On Sun, 2018-09-30 at 12:53 +0200, stefan.seyfried@xxxxxxxxxxxxxx wrote:
> From: Stefan Seyfried <seife+kernel@xxxxxxxxxxxxxx>
>
> cfg80211_wext_giwrate and sinfo.pertid might allocate sinfo.pertid via
> rdev_get_station(), but never release it
>
> Signed-off-by: Stefan Seyfried <seife+kernel@xxxxxxxxxxxxxx>
> ---
> net/wireless/wext-compat.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
> index 167f7025ac98..f462336aac1c 100644
> --- a/net/wireless/wext-compat.c
> +++ b/net/wireless/wext-compat.c
> @@ -1277,12 +1277,16 @@ static int cfg80211_wext_giwrate(struct net_device *dev,
> err = rdev_get_station(rdev, dev, addr, &sinfo);
> if (err)
> return err;
> -
> if (!(sinfo.filled & BIT_ULL(NL80211_STA_INFO_TX_BITRATE)))
> return -EOPNOTSUPP;
>
> rate->value = 100000 * cfg80211_calculate_bitrate(&sinfo.txrate);
>
> + /* sta_set_sinfo(), called from ieee80211_get_station(), called from
> + * rdev_get_station via rdev->ops->get_station, allocates pertid struct
> + * which we do not use here. */
> + kfree(sinfo.pertid);
> +
> return 0;
> }
>
> @@ -1293,7 +1297,7 @@ static struct iw_statistics *cfg80211_wireless_stats(struct net_device *dev)
> struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
> /* we are under RTNL - globally locked - so can use static structs */
> static struct iw_statistics wstats;
> - static struct station_info sinfo;
> + static struct station_info sinfo = {};
> u8 bssid[ETH_ALEN];
>
> if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_STATION)
> @@ -1352,6 +1356,9 @@ static struct iw_statistics *cfg80211_wireless_stats(struct net_device *dev)
> if (sinfo.filled & BIT_ULL(NL80211_STA_INFO_TX_FAILED))
> wstats.discard.retries = sinfo.tx_failed;
>
> + /* see cfg80211_wext_giwrate() above */
> + kfree(sinfo.pertid);
> +
> return &wstats;
> }
>
