iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ath9k: Protect queue draining by rcu_read_lock()

Browse Source 
commit 182b1917109892ab9f26d66bfdcbc4ba6f0a0a65 upstream.

When ath9k was switched over to use the mac80211 intermediate queues,
node cleanup now drains the mac80211 queues. However, this call path is
not protected by rcu_read_lock() as it was previously entirely internal
to the driver which uses its own locking.

This leads to a possible rcu_dereference() without holding
rcu_read_lock(); but only if a station is cleaned up while having
packets queued on the TXQ. Fix this by adding the rcu_read_lock() to the
caller in ath9k.

Fixes: 50f08edf9809 ("ath9k: Switch to using mac80211 intermediate software queues.")
Cc: stable@vger.kernel.org
Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Toke Høiland-Jørgensen 2018-02-27 19:09:44 +02:00 committed by Greg Kroah-Hartman
parent aa3bfa29fc
commit 3d06535693
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/wireless/ath/ath9k/xmit.c
View File

@ -2892,6 +2892,8 @@ void ath_tx_node_cleanup(struct ath_softc *sc, struct ath_node *an)
struct ath_txq *txq;
int tidno;
rcu_read_lock();
for (tidno = 0; tidno < IEEE80211_NUM_TIDS; tidno++) {
tid = ath_node_to_tid(an, tidno);
txq = tid->txq;
@ -2909,6 +2911,8 @@ void ath_tx_node_cleanup(struct ath_softc *sc, struct ath_node *an)
if (!an->sta)
break; /* just one multicast ath_atx_tid */
}
rcu_read_unlock();
}
#ifdef CONFIG_ATH9K_TX99