From b44e9bff9dd2840df8353c8c4c71b26a14e5dd70 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 22 Feb 2014 13:00:55 +0000 Subject: [PATCH] ath9k: add a tx locking fix Signed-off-by: Felix Fietkau SVN-Revision: 39684 --- .../mac80211/patches/300-pending_work.patch | 62 +++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/package/kernel/mac80211/patches/300-pending_work.patch b/package/kernel/mac80211/patches/300-pending_work.patch index a790183f74..be82f3704e 100644 --- a/package/kernel/mac80211/patches/300-pending_work.patch +++ b/package/kernel/mac80211/patches/300-pending_work.patch @@ -1,3 +1,43 @@ +commit a63caf0a357ad5c1f08d6b7827dc76c451445017 +Author: Stanislaw Gruszka +Date: Wed Feb 19 13:15:17 2014 +0100 + + ath9k: protect tid->sched check + + We check tid->sched without a lock taken on ath_tx_aggr_sleep(). That + is race condition which can result of doing list_del(&tid->list) twice + (second time with poisoned list node) and cause crash like shown below: + + [424271.637220] BUG: unable to handle kernel paging request at 00100104 + [424271.637328] IP: [] ath_tx_aggr_sleep+0x62/0xe0 [ath9k] + ... + [424271.639953] Call Trace: + [424271.639998] [] ? ath9k_get_survey+0x110/0x110 [ath9k] + [424271.640083] [] ath9k_sta_notify+0x42/0x50 [ath9k] + [424271.640177] [] sta_ps_start+0x8f/0x1c0 [mac80211] + [424271.640258] [] ? free_compound_page+0x2e/0x40 + [424271.640346] [] ieee80211_rx_handlers+0x9d5/0x2340 [mac80211] + [424271.640437] [] ? kmem_cache_free+0x1d8/0x1f0 + [424271.640510] [] ? kfree_skbmem+0x34/0x90 + [424271.640578] [] ? put_page+0x2c/0x40 + [424271.640640] [] ? kfree_skbmem+0x34/0x90 + [424271.640706] [] ? kfree_skbmem+0x34/0x90 + [424271.640787] [] ? ieee80211_rx_handlers_result+0x73/0x1d0 [mac80211] + [424271.640897] [] ieee80211_prepare_and_rx_handle+0x520/0xad0 [mac80211] + [424271.641009] [] ? ieee80211_rx_handlers+0x2ed/0x2340 [mac80211] + [424271.641104] [] ? ip_output+0x7e/0xd0 + [424271.641182] [] ieee80211_rx+0x307/0x7c0 [mac80211] + [424271.641266] [] ath_rx_tasklet+0x88e/0xf70 [ath9k] + [424271.641358] [] ? ieee80211_rx+0x1dc/0x7c0 [mac80211] + [424271.641445] [] ath9k_tasklet+0xcb/0x130 [ath9k] + + Bug report: + https://bugzilla.kernel.org/show_bug.cgi?id=70551 + + Reported-and-tested-by: Max Sydorenko + Cc: stable@vger.kernel.org + Signed-off-by: Stanislaw Gruszka + commit 82ed9e3ccc02797df2ffe4b78127c4cd5f799a41 Author: Felix Fietkau Date: Tue Feb 11 15:54:13 2014 +0100 @@ -2732,3 +2772,25 @@ Date: Thu Jan 23 20:06:34 2014 +0100 /* use the data classifier to determine what 802.1d tag the * data frame has */ rcu_read_lock(); +--- a/drivers/net/wireless/ath/ath9k/xmit.c ++++ b/drivers/net/wireless/ath/ath9k/xmit.c +@@ -1444,14 +1444,16 @@ void ath_tx_aggr_sleep(struct ieee80211_ + for (tidno = 0, tid = &an->tid[tidno]; + tidno < IEEE80211_NUM_TIDS; tidno++, tid++) { + +- if (!tid->sched) +- continue; +- + ac = tid->ac; + txq = ac->txq; + + ath_txq_lock(sc, txq); + ++ if (!tid->sched) { ++ ath_txq_unlock(sc, txq); ++ continue; ++ } ++ + buffered = ath_tid_has_buffered(tid); + + tid->sched = false;