From: Johannes Berg <johannes.berg@xxxxxxxxx>
When any interface goes down, it could be the one that we
were doing a remain-on-channel with. We therefore need to
cancel the remain-on-channel and flush the related work
structs so they don't run after the interface has been
removed or even destroyed.
It's also possible in this case that an off-channel SKB
was never transmitted, so free it if this is the case.
Note that this can also happen if the driver finishes
the off-channel period without ever starting it.
Cc: stable@xxxxxxxxxx
Reported-by: Nirav Shah <nirav.j2.shah@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
v2: actually cancel the roc and clean up after it
net/mac80211/iface.c | 12 ++++++++++++
net/mac80211/offchannel.c | 16 ++++++++++++++++
2 files changed, 28 insertions(+)
--- a/net/mac80211/iface.c 2012-05-31 14:29:52.000000000 +0200
+++ b/net/mac80211/iface.c 2012-05-31 15:03:22.000000000 +0200
@@ -637,6 +637,18 @@ static void ieee80211_do_stop(struct iee
ieee80211_configure_filter(local);
break;
default:
+ mutex_lock(&local->mtx);
+ if (local->hw_roc_dev == sdata->dev &&
+ local->hw_roc_channel) {
+ /* ignore return value since this is racy */
+ drv_cancel_remain_on_channel(local);
+ ieee80211_queue_work(&local->hw, &local->hw_roc_done);
+ }
+ mutex_unlock(&local->mtx);
+
+ flush_work(&local->hw_roc_start);
+ flush_work(&local->hw_roc_done);
+
flush_work(&sdata->work);
/*
* When we get here, the interface is marked down.
--- a/net/mac80211/offchannel.c 2012-05-31 14:48:54.000000000 +0200
+++ b/net/mac80211/offchannel.c 2012-05-31 14:48:57.000000000 +0200
@@ -234,6 +234,22 @@ static void ieee80211_hw_roc_done(struct
return;
}
+ /* was never transmitted */
+ if (local->hw_roc_skb) {
+ u64 cookie;
+
+ cookie = local->hw_roc_cookie ^ 2;
+
+ cfg80211_mgmt_tx_status(local->hw_roc_dev, cookie,
+ local->hw_roc_skb->data,
+ local->hw_roc_skb->len, false,
+ GFP_KERNEL);
+
+ kfree_skb(local->hw_roc_skb);
+ local->hw_roc_skb = NULL;
+ local->hw_roc_skb_for_status = NULL;
+ }
+
if (!local->hw_roc_for_tx)
cfg80211_remain_on_channel_expired(local->hw_roc_dev,
local->hw_roc_cookie,
--
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