lkml.org 
[lkml]   [2011]   [Dec]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[22/45] mac80211: fix race condition caused by late addBA response
    3.0-stable review patch.  If anyone has any objections, please let me know.

    ------------------


    From: Nikolay Martynov <mar.kolya@gmail.com>

    Upstream commit d305a6557b2c4dca0110f05ffe745b1ef94adb80.

    If addBA responses comes in just after addba_resp_timer has
    expired mac80211 will still accept it and try to open the
    aggregation session. This causes drivers to be confused and
    in some cases even crash.

    This patch fixes the race condition and makes sure that if
    addba_resp_timer has expired addBA response is not longer
    accepted and we do not try to open half-closed session.

    Signed-off-by: Nikolay Martynov <mar.kolya@gmail.com>
    [some adjustments]
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>
    Signed-off-by: John W. Linville <linville@tuxdriver.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    net/mac80211/agg-tx.c | 17 ++++++++++++++++-
    1 file changed, 16 insertions(+), 1 deletion(-)

    --- a/net/mac80211/agg-tx.c
    +++ b/net/mac80211/agg-tx.c
    @@ -792,12 +792,27 @@ void ieee80211_process_addba_resp(struct
    goto out;
    }

    - del_timer(&tid_tx->addba_resp_timer);
    + del_timer_sync(&tid_tx->addba_resp_timer);

    #ifdef CONFIG_MAC80211_HT_DEBUG
    printk(KERN_DEBUG "switched off addBA timer for tid %d\n", tid);
    #endif

    + /*
    + * addba_resp_timer may have fired before we got here, and
    + * caused WANT_STOP to be set. If the stop then was already
    + * processed further, STOPPING might be set.
    + */
    + if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) ||
    + test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) {
    +#ifdef CONFIG_MAC80211_HT_DEBUG
    + printk(KERN_DEBUG
    + "got addBA resp for tid %d but we already gave up\n",
    + tid);
    +#endif
    + goto out;
    + }
    +
    if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
    == WLAN_STATUS_SUCCESS) {
    /*



    \
     
     \ /
      Last update: 2011-12-16 21:03    [W:0.021 / U:120.580 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site