[PATCH AUTOSEL 5.4 129/330] mt76: clear skb pointers from rx aggregation reorder buffer during cleanup

Sasha Levin
2020-09-18T03:07:19Z

From: Felix Fietkau <nbd@nbd.name>

[ Upstream commit 9379df2fd9234e3b67a23101c2370c99f6af6d77 ]

During the cleanup of the aggregation session, a rx handler (or release timer)
on another CPU might still hold a pointer to the reorder buffer and could
attempt to release some packets.
Clearing pointers during cleanup avoids a theoretical use-after-free bug here.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/mediatek/mt76/agg-rx.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/mediatek/mt76/agg-rx.c b/drivers/net/wireless/mediatek/mt76/agg-rx.c
index cbff0dfc96311..f8441fd65400c 100644
--- a/drivers/net/wireless/mediatek/mt76/agg-rx.c
+++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c
@@ -268,6 +268,7 @@ static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid)
if (!skb)
continue;

+ tid->reorder_buf[i] = NULL;
tid->nframes--;
dev_kfree_skb(skb);
}
--
2.25.1