From 77cfaf52eca5cac30ed029507e0cab065f888995 Mon Sep 17 00:00:00 2001 From: Toke Høiland-Jørgensen Date: Mon, 13 Aug 2018 14:16:25 +0200 Subject: mac80211: Run TXQ teardown code before de-registering interfaces MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The TXQ teardown code can reference the vif data structures that are stored in the netdev private memory area if there are still packets on the queue when it is being freed. Since the TXQ teardown code is run after the netdevs are freed, this can lead to a use-after-free. Fix this by moving the TXQ teardown code to earlier in ieee80211_unregister_hw(). Reported-by: Ben Greear Tested-by: Ben Greear Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg --- net/mac80211/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/mac80211/main.c') diff --git a/net/mac80211/main.c b/net/mac80211/main.c index fb73451ed85e..0358f20b675f 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -1182,6 +1182,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) #if IS_ENABLED(CONFIG_IPV6) unregister_inet6addr_notifier(&local->ifa6_notifier); #endif + ieee80211_txq_teardown_flows(local); rtnl_lock(); @@ -1210,7 +1211,6 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) skb_queue_purge(&local->skb_queue); skb_queue_purge(&local->skb_queue_unreliable); skb_queue_purge(&local->skb_queue_tdls_chsw); - ieee80211_txq_teardown_flows(local); destroy_workqueue(local->workqueue); wiphy_unregister(local->hw.wiphy); -- cgit v1.2.3-70-g09d2 From 67d1ba8a6dc83d90cd58b89fa6cbf9ae35a0cf7f Mon Sep 17 00:00:00 2001 From: Danek Duvall Date: Wed, 22 Aug 2018 16:01:04 -0700 Subject: mac80211: correct use of IEEE80211_VHT_CAP_RXSTBC_X The mod mask for VHT capabilities intends to say that you can override the number of STBC receive streams, and it does, but only by accident. The IEEE80211_VHT_CAP_RXSTBC_X aren't bits to be set, but values (albeit left-shifted). ORing the bits together gets the right answer, but we should use the _MASK macro here instead. Signed-off-by: Danek Duvall Signed-off-by: Johannes Berg --- net/mac80211/main.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'net/mac80211/main.c') diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 0358f20b675f..27cd64acaf00 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -470,10 +470,7 @@ static const struct ieee80211_vht_cap mac80211_vht_capa_mod_mask = { cpu_to_le32(IEEE80211_VHT_CAP_RXLDPC | IEEE80211_VHT_CAP_SHORT_GI_80 | IEEE80211_VHT_CAP_SHORT_GI_160 | - IEEE80211_VHT_CAP_RXSTBC_1 | - IEEE80211_VHT_CAP_RXSTBC_2 | - IEEE80211_VHT_CAP_RXSTBC_3 | - IEEE80211_VHT_CAP_RXSTBC_4 | + IEEE80211_VHT_CAP_RXSTBC_MASK | IEEE80211_VHT_CAP_TXSTBC | IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE | IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE | -- cgit v1.2.3-70-g09d2 From f3ffb6c3a28963657eb8b02a795d75f2ebbd5ef4 Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Fri, 31 Aug 2018 11:31:06 +0300 Subject: mac80211: fix a race between restart and CSA flows We hit a problem with iwlwifi that was caused by a bug in mac80211. A bug in iwlwifi caused the firwmare to crash in certain cases in channel switch. Because of that bug, drv_pre_channel_switch would fail and trigger the restart flow. Now we had the hw restart worker which runs on the system's workqueue and the csa_connection_drop_work worker that runs on mac80211's workqueue that can run together. This is obviously problematic since the restart work wants to reconfigure the connection, while the csa_connection_drop_work worker does the exact opposite: it tries to disconnect. Fix this by cancelling the csa_connection_drop_work worker in the restart worker. Note that this can sound racy: we could have: driver iface_work CSA_work restart_work +++++++++++++++++++++++++++++++++++++++++++++ | <--drv_cs ---| -CS FAILED--> | | | cancel_work(CSA) schedule | CSA work | | | Race between those 2 But this is not possible because we flush the workqueue in the restart worker before we cancel the CSA worker. That would be bullet proof if we could guarantee that we schedule the CSA worker only from the iface_work which runs on the workqueue (and not on the system's workqueue), but unfortunately we do have an instance in which we schedule the CSA work outside the context of the workqueue (ieee80211_chswitch_done). Note also that we should probably cancel other workers like beacon_connection_loss_work and possibly others for different types of interfaces, at the very least, IBSS should suffer from the exact same problem, but for now, do the minimum to fix the actual bug that was actually experienced and reproduced. Signed-off-by: Emmanuel Grumbach Signed-off-by: Luca Coelho Signed-off-by: Johannes Berg --- net/mac80211/main.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'net/mac80211/main.c') diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 27cd64acaf00..66cbddd65b47 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -255,8 +255,27 @@ static void ieee80211_restart_work(struct work_struct *work) flush_work(&local->radar_detected_work); rtnl_lock(); - list_for_each_entry(sdata, &local->interfaces, list) + list_for_each_entry(sdata, &local->interfaces, list) { + /* + * XXX: there may be more work for other vif types and even + * for station mode: a good thing would be to run most of + * the iface type's dependent _stop (ieee80211_mg_stop, + * ieee80211_ibss_stop) etc... + * For now, fix only the specific bug that was seen: race + * between csa_connection_drop_work and us. + */ + if (sdata->vif.type == NL80211_IFTYPE_STATION) { + /* + * This worker is scheduled from the iface worker that + * runs on mac80211's workqueue, so we can't be + * scheduling this worker after the cancel right here. + * The exception is ieee80211_chswitch_done. + * Then we can have a race... + */ + cancel_work_sync(&sdata->u.mgd.csa_connection_drop_work); + } flush_delayed_work(&sdata->dec_tailroom_needed_wk); + } ieee80211_scan_cancel(local); /* make sure any new ROC will consider local->in_reconfig */ -- cgit v1.2.3-70-g09d2