Messages in this thread Patch in this message | | | Date | Wed, 11 Apr 2012 16:13:22 -0700 | From | Greg KH <> | Subject | [ 15/42] mac80211: fix possible tid_rx->reorder_timer use after free |
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3.0-stable review patch. If anyone has any objections, please let me know.
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From: Stanislaw Gruszka <sgruszka@redhat.com>
commit d72308bff5c2fa207949a5925b020bce74495e33 upstream.
Is possible that we will arm the tid_rx->reorder_timer after del_timer_sync() in ___ieee80211_stop_rx_ba_session(). We need to stop timer after RCU grace period finish, so move it to ieee80211_free_tid_rx(). Timer will not be armed again, as rcu_dereference(sta->ampdu_mlme.tid_rx[tid]) will return NULL.
Debug object detected problem with the following warning: ODEBUG: free active (active state 0) object type: timer_list hint: sta_rx_agg_reorder_timer_expired+0x0/0xf0 [mac80211]
Bug report (with all warning messages): https://bugzilla.redhat.com/show_bug.cgi?id=804007
Reported-by: "jan p. springer" <jsd@igroup.org> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/mac80211/agg-rx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/mac80211/agg-rx.c +++ b/net/mac80211/agg-rx.c @@ -48,6 +48,8 @@ static void ieee80211_free_tid_rx(struct container_of(h, struct tid_ampdu_rx, rcu_head); int i; + del_timer_sync(&tid_rx->reorder_timer); + for (i = 0; i < tid_rx->buf_size; i++) dev_kfree_skb(tid_rx->reorder_buf[i]); kfree(tid_rx->reorder_buf); @@ -87,7 +89,6 @@ void ___ieee80211_stop_rx_ba_session(str tid, 0, reason); del_timer_sync(&tid_rx->session_timer); - del_timer_sync(&tid_rx->reorder_timer); call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx); }
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