diff options
| author | Johannes Berg <johannes@sipsolutions.net> | 2009-11-22 12:28:41 +0100 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-11-30 13:55:51 -0500 |
| commit | 827d42c9ac91ddd728e4f4a31fefb906ef2ceff7 (patch) | |
| tree | e29371d79d63d0a3ec2cb6d010b71147853fc771 /net/mac80211/agg-tx.c | |
| parent | 4253119acf412fd686ef4bd8749b5a4d70ea3a51 (diff) | |
mac80211: fix spurious delBA handling
Lennert Buytenhek noticed that delBA handling in mac80211
was broken and has remotely triggerable problems, some of
which are due to some code shuffling I did that ended up
changing the order in which things were done -- this was
commit d75636ef9c1af224f1097941879d5a8db7cd04e5
Author: Johannes Berg <johannes@sipsolutions.net>
Date: Tue Feb 10 21:25:53 2009 +0100
mac80211: RX aggregation: clean up stop session
and other parts were already present in the original
commit d92684e66091c0f0101819619b315b4bb8b5bcc5
Author: Ron Rindjunsky <ron.rindjunsky@intel.com>
Date: Mon Jan 28 14:07:22 2008 +0200
mac80211: A-MPDU Tx add delBA from recipient support
The first problem is that I moved a BUG_ON before various
checks -- thereby making it possible to hit. As the comment
indicates, the BUG_ON can be removed since the ampdu_action
callback must already exist when the state is != IDLE.
The second problem isn't easily exploitable but there's a
race condition due to unconditionally setting the state to
OPERATIONAL when a delBA frame is received, even when no
aggregation session was ever initiated. All the drivers
accept stopping the session even then, but that opens a
race window where crashes could happen before the driver
accepts it. Right now, a WARN_ON may happen with non-HT
drivers, while the race opens only for HT drivers.
For this case, there are two things necessary to fix it:
1) don't process spurious delBA frames, and be more careful
about the session state; don't drop the lock
2) HT drivers need to be prepared to handle a session stop
even before the session was really started -- this is
true for all drivers (that support aggregation) but
iwlwifi which can be fixed easily. The other HT drivers
(ath9k and ar9170) are behaving properly already.
Reported-by: Lennert Buytenhek <buytenh@marvell.com>
Cc: stable@kernel.org
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/agg-tx.c')
| -rw-r--r-- | net/mac80211/agg-tx.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index 63224d1ee8dd..89e238b001de 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -123,13 +123,18 @@ void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u1 ieee80211_tx_skb(sdata, skb, 0); } -static int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, - enum ieee80211_back_parties initiator) +int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, + enum ieee80211_back_parties initiator) { struct ieee80211_local *local = sta->local; int ret; u8 *state; +#ifdef CONFIG_MAC80211_HT_DEBUG + printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", + sta->sta.addr, tid); +#endif /* CONFIG_MAC80211_HT_DEBUG */ + state = &sta->ampdu_mlme.tid_state_tx[tid]; if (*state == HT_AGG_STATE_OPERATIONAL) @@ -143,7 +148,6 @@ static int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, /* HW shall not deny going back to legacy */ if (WARN_ON(ret)) { - *state = HT_AGG_STATE_OPERATIONAL; /* * We may have pending packets get stuck in this case... * Not bothering with a workaround for now. @@ -525,11 +529,6 @@ int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, goto unlock; } -#ifdef CONFIG_MAC80211_HT_DEBUG - printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n", - sta->sta.addr, tid); -#endif /* CONFIG_MAC80211_HT_DEBUG */ - ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator); unlock: |