Commit 046cc2ef authored by Jérôme Pouiller's avatar Jérôme Pouiller Committed by Greg Kroah-Hartman
Browse files

staging: wfx: fix RCU usage in wfx_join_finalize() 



Access to sta->ht_cap is protected by RCU. However,
hif_set_association_mode() may sleep, so it can't be called in RCU.

This patch fix this behavior by handling sta and its RCU directly from
function hif_set_association_mode().

Signed-off-by: default avatarJérôme Pouiller <jerome.pouiller@silabs.com>
Fixes: d0014901 ("staging: wfx: fix RCU usage")
Link: https://lore.kernel.org/r/20200310101356.182818-5-Jerome.Pouiller@silabs.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4bbc6a3e

drivers/staging/wfx/hif_tx_mib.h

+10 −5
Original line number Diff line number Diff line
@@ -191,10 +191,10 @@ static inline int hif_set_block_ack_policy(struct wfx_vif *wvif, 
}



static inline int hif_set_association_mode(struct wfx_vif *wvif,

					   struct ieee80211_bss_conf *info,

					   struct ieee80211_sta_ht_cap *ht_cap)

					   struct ieee80211_bss_conf *info)

{

	int basic_rates = wfx_rate_mask_to_hw(wvif->wdev, info->basic_rates);

	struct ieee80211_sta *sta = NULL;

	struct hif_mib_set_association_mode val = {

		.preambtype_use = 1,

		.mode = 1,
@@ -204,12 +204,17 @@ static inline int hif_set_association_mode(struct wfx_vif *wvif, 
		.basic_rate_set = cpu_to_le32(basic_rates)

	};



	rcu_read_lock(); // protect sta

	if (info->bssid && !info->ibss_joined)

		sta = ieee80211_find_sta(wvif->vif, info->bssid);



	// FIXME: it is strange to not retrieve all information from bss_info

	if (ht_cap && ht_cap->ht_supported) {

		val.mpdu_start_spacing = ht_cap->ampdu_density;

	if (sta && sta->ht_cap.ht_supported) {

		val.mpdu_start_spacing = sta->ht_cap.ampdu_density;

		if (!(info->ht_operation_mode & IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT))

			val.greenfield = !!(ht_cap->cap & IEEE80211_HT_CAP_GRN_FLD);

			val.greenfield = !!(sta->ht_cap.cap & IEEE80211_HT_CAP_GRN_FLD);

	}

	rcu_read_unlock();



	return hif_write_mib(wvif->wdev, wvif->id,

			     HIF_MIB_ID_SET_ASSOCIATION_MODE, &val, sizeof(val));

drivers/staging/wfx/sta.c

+2 −2
Original line number Diff line number Diff line
@@ -691,6 +691,7 @@ static void wfx_join_finalize(struct wfx_vif *wvif, 
			wfx_rate_mask_to_hw(wvif->wdev, sta->supp_rates[wvif->channel->band]);

	else

		wvif->bss_params.operational_rate_set = -1;

	rcu_read_unlock();

	if (sta &&

	    info->ht_operation_mode & IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT)

		hif_dual_cts_protection(wvif, true);
@@ -703,8 +704,7 @@ static void wfx_join_finalize(struct wfx_vif *wvif, 
	wvif->bss_params.beacon_lost_count = 20;

	wvif->bss_params.aid = info->aid;



	hif_set_association_mode(wvif, info, sta ? &sta->ht_cap : NULL);

	rcu_read_unlock();

	hif_set_association_mode(wvif, info);



	if (!info->ibss_joined) {

		hif_keep_alive_period(wvif, 30 /* sec */);

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