1. 30 Nov, 2009 2 commits
    • Johannes Berg's avatar
      mac80211: fix spurious delBA handling · 827d42c9
      Johannes Berg authored
      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 d75636ef
        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 d92684e6
      
      
        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: default avatarLennert Buytenhek <buytenh@marvell.com>
      Cc: stable@kernel.org
      Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
      827d42c9
    • Johannes Berg's avatar
      mac80211: fix two remote exploits · 4253119a
      Johannes Berg authored
      Lennert Buytenhek noticed a remotely triggerable problem
      in mac80211, which is due to some code shuffling I did
      that ended up changing the order in which things were
      done -- this was in
      
        commit d75636ef
      
      
        Author: Johannes Berg <johannes@sipsolutions.net>
        Date:   Tue Feb 10 21:25:53 2009 +0100
      
          mac80211: RX aggregation: clean up stop session
      
      The problem is that the BUG_ON moved before the various
      checks, and as such can be triggered.
      
      As the comment indicates, the BUG_ON can be removed since
      the ampdu_action callback must already exist when the
      state is OPERATIONAL.
      
      A similar code path leads to a WARN_ON in
      ieee80211_stop_tx_ba_session, which can also be removed.
      
      Cc: stable@kernel.org [2.6.29+]
      Cc: Lennert Buytenhek <buytenh@marvell.com>
      Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
      4253119a
  2. 24 Nov, 2009 1 commit
  3. 23 Nov, 2009 11 commits
  4. 22 Nov, 2009 1 commit
  5. 21 Nov, 2009 3 commits
  6. 20 Nov, 2009 11 commits
  7. 19 Nov, 2009 5 commits
  8. 18 Nov, 2009 6 commits