From: Arik Nemtsov <arik@xxxxxxxxxx>
TDLS off-channel can be allowed in channels marked with GO_CONCURRENT,
provided the device is connected to an AP on the same UNII.
When relaxing the NO-IR requirements for TDLS, we might hit flows in
cfg80211_reg_can_beacon that acquire the wdev lock. Take some measures
to allow this during TDLS setup.
Acquire the RCU read lock later in the flow that invokes
cfg80211_reg_can_beacon.
Avoid taking local->mtx when preparing the setup packet to avoid
circular deadlocks with mac80211 code that is invoked with wdev-mtx
held.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@xxxxxxxxx>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
---
net/mac80211/tdls.c | 41 ++++++++++++++++++++++++-----------------
1 file changed, 24 insertions(+), 17 deletions(-)
diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index 5bcd542..bc7e404 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -287,17 +287,6 @@ ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
size_t offset = 0, noffset;
u8 *pos;
- rcu_read_lock();
-
- /* we should have the peer STA if we're already responding */
- if (action_code == WLAN_TDLS_SETUP_RESPONSE) {
- sta = sta_info_get(sdata, peer);
- if (WARN_ON_ONCE(!sta)) {
- rcu_read_unlock();
- return;
- }
- }
-
ieee80211_add_srates_ie(sdata, skb, false, band);
ieee80211_add_ext_srates_ie(sdata, skb, false, band);
ieee80211_tdls_add_supp_channels(sdata, skb);
@@ -350,6 +339,17 @@ ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
offset = noffset;
}
+ rcu_read_lock();
+
+ /* we should have the peer STA if we're already responding */
+ if (action_code == WLAN_TDLS_SETUP_RESPONSE) {
+ sta = sta_info_get(sdata, peer);
+ if (WARN_ON_ONCE(!sta)) {
+ rcu_read_unlock();
+ return;
+ }
+ }
+
/*
* with TDLS we can switch channels, and HT-caps are not necessarily
* the same on all bands. The specification limits the setup to a
@@ -983,7 +983,7 @@ ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
if (!is_zero_ether_addr(sdata->u.mgd.tdls_peer) &&
!ether_addr_equal(sdata->u.mgd.tdls_peer, peer)) {
ret = -EBUSY;
- goto exit;
+ goto out_unlock;
}
/*
@@ -998,27 +998,34 @@ ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
if (!sta_info_get(sdata, peer)) {
rcu_read_unlock();
ret = -ENOLINK;
- goto exit;
+ goto out_unlock;
}
rcu_read_unlock();
}
ieee80211_flush_queues(local, sdata, false);
+ memcpy(sdata->u.mgd.tdls_peer, peer, ETH_ALEN);
+ mutex_unlock(&local->mtx);
+ /* we cannot take the mutex while preparing the setup packet */
ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
dialog_token, status_code,
peer_capability, initiator,
extra_ies, extra_ies_len, 0,
NULL);
- if (ret < 0)
- goto exit;
+ if (ret < 0) {
+ mutex_lock(&local->mtx);
+ eth_zero_addr(sdata->u.mgd.tdls_peer);
+ mutex_unlock(&local->mtx);
+ return ret;
+ }
- memcpy(sdata->u.mgd.tdls_peer, peer, ETH_ALEN);
ieee80211_queue_delayed_work(&sdata->local->hw,
&sdata->u.mgd.tdls_peer_del_work,
TDLS_PEER_SETUP_TIMEOUT);
+ return 0;
-exit:
+out_unlock:
mutex_unlock(&local->mtx);
return ret;
}
--
1.9.1
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