[PATCH AUTOSEL 4.19 079/206] mt76: clear skb pointers from rx aggregation reorder buffer during cleanup

Sasha Levin sashal at kernel.org
Thu Sep 17 22:05:55 EDT 2020

From: Felix Fietkau <nbd at 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 at nbd.name>
Signed-off-by: Sasha Levin <sashal at 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 d44d57e6eb27a..97df6b3a472b1 100644
--- a/drivers/net/wireless/mediatek/mt76/agg-rx.c
+++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c
@@ -278,6 +278,7 @@ static void mt76_rx_aggr_shutdown(struct mt76_dev *dev, struct mt76_rx_tid *tid)
 		if (!skb)
+		tid->reorder_buf[i] = NULL;

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