From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
This fixes OOM when using pktgen to drive a wifi station at more than
the station can transmit. pktgen uses ndo_start_xmit instead of going
through the queue layer, so it will not back off when the queues are
stopped, and would thus cause packets to be added to the txqi->queue
until the system goes OOM and crashes.
Signed-off-by: Ben Greear <greearb@xxxxxxxxxxxxxxx>
---
This is against 4.7.10+, not sure if it is actually needed in latest kernel.
net/mac80211/tx.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index fbcb5fc..0573ab9 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1293,6 +1293,16 @@ static void ieee80211_drv_tx(struct ieee80211_local *local,
goto tx_normal;
ac = txq->ac;
+
+ if (atomic_read(&sdata->txqs_len[ac]) >=
+ (local->hw.txq_ac_max_pending * 2)) {
+ /* Must be that something is not paying attention to
+ * max-pending, like pktgen, so just drop this frame.
+ */
+ ieee80211_free_txskb(&local->hw, skb);
+ return;
+ }
+
txqi = to_txq_info(txq);
atomic_inc(&sdata->txqs_len[ac]);
if (atomic_read(&sdata->txqs_len[ac]) >= local->hw.txq_ac_max_pending)
--
2.4.11
