[Intel-wired-lan] [PATCH 3/3 net-next v5] igb/igc: RX queues: fix DMA leak in error case

[Lennert Buytenhek <buytenh@wantstofly.org>]

On Mon, Jan 17, 2022 at 07:29:15PM +0100, Corinna Vinschen wrote:

> When setting up the rx queues, igb and igc neglect to free DMA memory
> in error case.  Add matching dma_free_coherent calls.
> 
> Signed-off-by: Corinna Vinschen <vinschen@redhat.com>
> ---
>  drivers/net/ethernet/intel/igb/igb_main.c | 1 +
>  drivers/net/ethernet/intel/igc/igc_main.c | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index cea89d301bfd..343568d4ff7f 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -4389,6 +4389,7 @@ int igb_setup_rx_resources(struct igb_ring *rx_ring)
>  	return 0;
>  
>  err:
> +	dma_free_coherent(dev, rx_ring->size, rx_ring->desc, rx_ring->dma);
>  	vfree(rx_ring->rx_buffer_info);
>  	rx_ring->rx_buffer_info = NULL;
>  	dev_err(dev, "Unable to allocate memory for the Rx descriptor ring\n");
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> index 56ed0f1463e5..f323cec0b74f 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -540,6 +540,7 @@ int igc_setup_rx_resources(struct igc_ring *rx_ring)
>  	return 0;
>  
>  err:
> +	dma_free_coherent(dev, rx_ring->size, rx_ring->desc, rx_ring->dma);
>  	vfree(rx_ring->rx_buffer_info);
>  	rx_ring->rx_buffer_info = NULL;
>  	netdev_err(ndev, "Unable to allocate memory for Rx descriptor ring\n");

If the vzalloc() call in igc_setup_rx_resources() fails, and we jump
to 'err' before dma_alloc_coherent() was reached, won't dma_free_coherent()
be called inadvertently here?