Re: [PATCH] net: ethernet: mtk_wed: fix double free in mtk_wed_rx_reset

From: Lorenzo Bianconi

Date: Thu Nov 05 2026 - 03:34:23 EST


> mtk_wed_free_rx_buffer already calls mtk_wed_hwrro_free_buffer but
> mtk_wed_rx_reset calls both subsequently. This would cause double free
> because dma_free_coherent doesn't set freed desc to NULL.
>
> Fix this by removing the mtk_wed_hwrro_free_buffer in mtk_wed_rx_reset.
>
> Compile tested only because I don't own v3 hardware.
>
> Fixes: 1543b8ff02f0 ("net: ethernet: mtk_wed: add wed 3.0 reset support")
> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> Link: https://sashiko.dev/#/map/216156
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Zhi-Jun You <hujy652@xxxxxxxxx>

Reviewed-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>

> ---
> drivers/net/ethernet/mediatek/mtk_wed.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
> index f40ac5794341..5e9674c9e63a 100644
> --- a/drivers/net/ethernet/mediatek/mtk_wed.c
> +++ b/drivers/net/ethernet/mediatek/mtk_wed.c
> @@ -1723,7 +1723,6 @@ mtk_wed_rx_reset(struct mtk_wed_device *dev)
> false);
> }
> mtk_wed_free_rx_buffer(dev);
> - mtk_wed_hwrro_free_buffer(dev);
>
> return 0;
> }
>
> ---
> base-commit: 11140c51df12e594d6bf2c8d2af5dec63b0219ac
> change-id: 20261104-double-free-b6b95c2539c6
>
> Best regards,
> --
> Zhi-Jun You <hujy652@xxxxxxxxx>
>

Attachment: signature.asc
Description: PGP signature