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authorStanislaw Gruszka <sgruszka@redhat.com>2014-02-19 13:15:17 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-07 13:25:40 -0700
commit4237cc8ef3fc3916c337423cbaab818890e628c8 (patch)
tree845404c6d16ea302640d72a6e9913e96f2653c5c
parent3c3fa08f4c7770ad35bb10755fb9b1c80e34dee4 (diff)
downloadlinux-linaro-stable-4237cc8ef3fc3916c337423cbaab818890e628c8.tar.gz
ath9k: protect tid->sched check
[ Upstream commit 21f8aaee0c62708654988ce092838aa7df4d25d8 ] 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> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> [ xl: backported to 3.10: adjusted context ] Signed-off-by: Xiangyu Lu <luxiangyu@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/wireless/ath/ath9k/xmit.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index e752f5d4995d..0c9b2f1c6939 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1255,14 +1255,16 @@ void ath_tx_aggr_sleep(struct ieee80211_sta *sta, struct ath_softc *sc,
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 = !skb_queue_empty(&tid->buf_q);
tid->sched = false;