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ath9k: add a tx locking fix

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Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 39684
This commit is contained in:
Felix Fietkau 2014-02-22 13:00:55 +00:00
parent c1f397e1e1
commit b44e9bff9d
1 changed files with 62 additions and 0 deletions
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62
package/kernel/mac80211/patches/300-pending_work.patch
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@ -1,3 +1,43 @@
commit a63caf0a357ad5c1f08d6b7827dc76c451445017
Author: Stanislaw Gruszka <sgruszka@redhat.com>
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: [<f90fc072>] ath_tx_aggr_sleep+0x62/0xe0 [ath9k]
...
[424271.639953] Call Trace:
[424271.639998] [<f90f6900>] ? ath9k_get_survey+0x110/0x110 [ath9k]
[424271.640083] [<f90f6942>] ath9k_sta_notify+0x42/0x50 [ath9k]
[424271.640177] [<f809cfef>] sta_ps_start+0x8f/0x1c0 [mac80211]
[424271.640258] [<c10f730e>] ? free_compound_page+0x2e/0x40
[424271.640346] [<f809e915>] ieee80211_rx_handlers+0x9d5/0x2340 [mac80211]
[424271.640437] [<c112f048>] ? kmem_cache_free+0x1d8/0x1f0
[424271.640510] [<c1345a84>] ? kfree_skbmem+0x34/0x90
[424271.640578] [<c10fc23c>] ? put_page+0x2c/0x40
[424271.640640] [<c1345a84>] ? kfree_skbmem+0x34/0x90
[424271.640706] [<c1345a84>] ? kfree_skbmem+0x34/0x90
[424271.640787] [<f809dde3>] ? ieee80211_rx_handlers_result+0x73/0x1d0 [mac80211]
[424271.640897] [<f80a07a0>] ieee80211_prepare_and_rx_handle+0x520/0xad0 [mac80211]
[424271.641009] [<f809e22d>] ? ieee80211_rx_handlers+0x2ed/0x2340 [mac80211]
[424271.641104] [<c13846ce>] ? ip_output+0x7e/0xd0
[424271.641182] [<f80a1057>] ieee80211_rx+0x307/0x7c0 [mac80211]
[424271.641266] [<f90fa6ee>] ath_rx_tasklet+0x88e/0xf70 [ath9k]
[424271.641358] [<f80a0f2c>] ? ieee80211_rx+0x1dc/0x7c0 [mac80211]
[424271.641445] [<f90f82db>] ath9k_tasklet+0xcb/0x130 [ath9k]
Bug report:
https://bugzilla.kernel.org/show_bug.cgi?id=70551
Reported-and-tested-by: Max Sydorenko <maxim.stargazer@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
commit 82ed9e3ccc02797df2ffe4b78127c4cd5f799a41
Author: Felix Fietkau <nbd@openwrt.org>
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;