This is a note to let you know that I've just added the patch titled mac80211: recalculate min channel width on VHT opmode changes to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mac80211-recalculate-min-channel-width-on-vht-opmode-changes.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Jul 3 13:29:10 CEST 2017 From: Johannes Berg <johannes.berg@xxxxxxxxx> Date: Thu, 20 Oct 2016 08:52:50 +0200 Subject: mac80211: recalculate min channel width on VHT opmode changes From: Johannes Berg <johannes.berg@xxxxxxxxx> [ Upstream commit d2941df8fbd9708035d66d889ada4d3d160170ce ] When an associated station changes its VHT operating mode this can/will affect the bandwidth it's using, and consequently we must recalculate the minimum bandwidth we need to use. Failure to do so can lead to one of two scenarios: 1) we use a too high bandwidth, this is benign 2) we use a too narrow bandwidth, causing rate control and actual PHY configuration to be out of sync, which can in turn cause problems/crashes Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mac80211/iface.c | 21 +++++++++++++++++++++ net/mac80211/rx.c | 9 +-------- net/mac80211/vht.c | 4 +++- 3 files changed, 25 insertions(+), 9 deletions(-) --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -6,6 +6,7 @@ * Copyright (c) 2006 Jiri Benc <jbenc@xxxxxxx> * Copyright 2008, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> * Copyright 2013-2014 Intel Mobile Communications GmbH + * Copyright (c) 2016 Intel Deutschland GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -1307,6 +1308,26 @@ static void ieee80211_iface_work(struct } else if (ieee80211_is_action(mgmt->frame_control) && mgmt->u.action.category == WLAN_CATEGORY_VHT) { switch (mgmt->u.action.u.vht_group_notif.action_code) { + case WLAN_VHT_ACTION_OPMODE_NOTIF: { + struct ieee80211_rx_status *status; + enum nl80211_band band; + u8 opmode; + + status = IEEE80211_SKB_RXCB(skb); + band = status->band; + opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode; + + mutex_lock(&local->sta_mtx); + sta = sta_info_get_bss(sdata, mgmt->sa); + + if (sta) + ieee80211_vht_handle_opmode(sdata, sta, + opmode, + band); + + mutex_unlock(&local->sta_mtx); + break; + } case WLAN_VHT_ACTION_GROUPID_MGMT: ieee80211_process_mu_groups(sdata, mgmt); break; --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2923,17 +2923,10 @@ ieee80211_rx_h_action(struct ieee80211_r switch (mgmt->u.action.u.vht_opmode_notif.action_code) { case WLAN_VHT_ACTION_OPMODE_NOTIF: { - u8 opmode; - /* verify opmode is present */ if (len < IEEE80211_MIN_ACTION_SIZE + 2) goto invalid; - - opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode; - - ieee80211_vht_handle_opmode(rx->sdata, rx->sta, - opmode, status->band); - goto handled; + goto queue; } case WLAN_VHT_ACTION_GROUPID_MGMT: { if (len < IEEE80211_MIN_ACTION_SIZE + 25) --- a/net/mac80211/vht.c +++ b/net/mac80211/vht.c @@ -527,8 +527,10 @@ void ieee80211_vht_handle_opmode(struct u32 changed = __ieee80211_vht_handle_opmode(sdata, sta, opmode, band); - if (changed > 0) + if (changed > 0) { + ieee80211_recalc_min_chandef(sdata); rate_control_rate_update(local, sband, sta, changed); + } } void ieee80211_get_vht_mask_from_cap(__le16 vht_cap, Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are queue-4.9/mac80211-recalculate-min-channel-width-on-vht-opmode-changes.patch