From: Deren Wu <deren.wu@xxxxxxxxxxxx>
[ Upstream commit 5f54237ad798f41cb6a503271aa9ca47188cfb9b ]
Ensure the entry has been fully updated before SDIO bus worker access
it. This patch would fix potential memory risk in both mt7663s and
mt7921s.
Fixes: 764dee47e2c1 ("mt76: sdio: move common code in mt76_sdio module")
Signed-off-by: Deren Wu <deren.wu@xxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/sdio.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/wireless/mediatek/mt76/sdio.c b/drivers/net/wireless/mediatek/mt76/sdio.c
index 0ec308f99af5a..176207f3177c4 100644
--- a/drivers/net/wireless/mediatek/mt76/sdio.c
+++ b/drivers/net/wireless/mediatek/mt76/sdio.c
@@ -562,6 +562,10 @@ mt76s_tx_queue_skb_raw(struct mt76_dev *dev, struct mt76_queue *q,
q->entry[q->head].buf_sz = len;
q->entry[q->head].skb = skb;
+
+ /* ensure the entry fully updated before bus access */
+ smp_wmb();
+
q->head = (q->head + 1) % q->ndesc;
q->queued++;
--
2.39.2
