Check for NULL pointer to avoid kernel crashing in case of missing WO
firmware in case only a single WEDv2 device has been initialized, e.g. on
MT7981 which can connect just one wireless frontend.

Fixes: 86ce0d09e424 ("net: ethernet: mtk_eth_soc: use WO firmware for MT7981")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/net/ethernet/mediatek/mtk_wed.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 4c205afbd230..985cff910f30 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -654,7 +654,7 @@ __mtk_wed_detach(struct mtk_wed_device *dev)
 					   BIT(hw->index), BIT(hw->index));
 	}
 
-	if (!hw_list[!hw->index]->wed_dev &&
+	if ((!hw_list[!hw->index] || !hw_list[!hw->index]->wed_dev) &&
 	    hw->eth->dma_dev != hw->eth->dev)
 		mtk_eth_set_dma_device(hw->eth, hw->eth->dev);
 
-- 
2.40.0

Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Tue, 9 May 2023 03:20:06 +0200 you wrote:
> Check for NULL pointer to avoid kernel crashing in case of missing WO
> firmware in case only a single WEDv2 device has been initialized, e.g. on
> MT7981 which can connect just one wireless frontend.
> 
> Fixes: 86ce0d09e424 ("net: ethernet: mtk_eth_soc: use WO firmware for MT7981")
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> 
> [...]

Here is the summary with links:
  - [net] net: ethernet: mtk_eth_soc: fix NULL pointer dereference
    https://git.kernel.org/netdev/net/c/7c83e28f1083

You are awesome, thank you!
-- 
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On Tue, May 09, 2023 at 03:20:06AM +0200, Daniel Golle wrote:
> Check for NULL pointer to avoid kernel crashing in case of missing WO
> firmware in case only a single WEDv2 device has been initialized, e.g. on
> MT7981 which can connect just one wireless frontend.
> 
> Fixes: 86ce0d09e424 ("net: ethernet: mtk_eth_soc: use WO firmware for MT7981")
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Reviewed-by: Simon Horman <simon.horman@corigine.com>