Re: [PATCH 1/2] eth: mlx5: fix double free of flow_table groups on allocation failure

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 04/09/2025 17:08, Makar Semyonov wrote:
> In macsec_fs_rx_create_crypto_table_groups(), when memory allocation for
> 'in' fails, 'ft->g' is cleared once. However, the function returns
> a non-zero error which causes macsec_fs_rx_destroy to be called.
> Inside it, macsec_fs_destroy_flow_table is invoked, which attempts
> to clear 'ft->g' again, leading to a double free.
> 
> This commit fixes the issue by setting 'ft->g' to NULL immediately
> after the first clearance in macsec_fs_rx_create_crypto_table_groups()
> to prevent a double free when macsec_fs_destroy_flow_table attempts to
> free it again.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Signed-off-by: Makar Semyonov <m.semenov@tssltd.ru>
> ---
>   drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c
> index 4a078113e292..5e86c277f33a 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/macsec_fs.c
> @@ -1066,6 +1066,7 @@ static int macsec_fs_rx_create_crypto_table_groups(struct mlx5_macsec_flow_table
>   	in = kvzalloc(inlen, GFP_KERNEL);
>   	if (!in) {
>   		kfree(ft->g);
> +		ft->g = NULL;
>   		return -ENOMEM;
>   	}
>   

Code and commit message are fine.
Use "net/mlx5" prefix.
Please address comments from Markus Elfring.