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author | Johannes Berg <johannes@sipsolutions.net> | 2009-11-22 12:28:41 +0100 |
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committer | John W. Linville <linville@tuxdriver.com> | 2009-11-30 13:55:51 -0500 |
commit | 827d42c9ac91ddd728e4f4a31fefb906ef2ceff7 (patch) | |
tree | e29371d79d63d0a3ec2cb6d010b71147853fc771 /drivers/net/wireless/iwlwifi | |
parent | 4253119acf412fd686ef4bd8749b5a4d70ea3a51 (diff) | |
download | op-kernel-dev-827d42c9ac91ddd728e4f4a31fefb906ef2ceff7.zip op-kernel-dev-827d42c9ac91ddd728e4f4a31fefb906ef2ceff7.tar.gz |
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 'drivers/net/wireless/iwlwifi')
-rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-tx.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c index fb9bcfa..b7e196e 100644 --- a/drivers/net/wireless/iwlwifi/iwl-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c @@ -1277,8 +1277,16 @@ int iwl_tx_agg_stop(struct iwl_priv *priv , const u8 *ra, u16 tid) return -ENXIO; } + if (priv->stations[sta_id].tid[tid].agg.state == + IWL_EMPTYING_HW_QUEUE_ADDBA) { + IWL_DEBUG_HT(priv, "AGG stop before setup done\n"); + ieee80211_stop_tx_ba_cb_irqsafe(priv->hw, ra, tid); + priv->stations[sta_id].tid[tid].agg.state = IWL_AGG_OFF; + return 0; + } + if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_ON) - IWL_WARN(priv, "Stopping AGG while state not IWL_AGG_ON\n"); + IWL_WARN(priv, "Stopping AGG while state not ON or starting\n"); tid_data = &priv->stations[sta_id].tid[tid]; ssn = (tid_data->seq_number & IEEE80211_SCTL_SEQ) >> 4; |