Re: [PATCH] [v2] net/mlx5e: fix a potential double-free in fs_any_create_groups

Tariq Toukan
2023-11-28T12:53:46Z

On 28/11/2023 11:29, Dinghao Liu wrote:
> When kcalloc() for ft->g succeeds but kvzalloc() for in fails,
> fs_any_create_groups() will free ft->g. However, its caller
> fs_any_create_table() will free ft->g again through calling
> mlx5e_destroy_flow_table(), which will lead to a double-free.
> Fix this by setting ft->g to NULL in fs_any_create_groups().
>
> Fixes: 0f575c20bf06 ("net/mlx5e: Introduce Flow Steering ANY API")
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>
> Changelog:
>
> v2: Setting ft->g to NULL instead of removing the kfree().
> ---
> drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c
> index be83ad9db82a..6207ffe74233 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c
> @@ -435,6 +435,7 @@ static int fs_any_create_groups(struct mlx5e_flow_table *ft)
> in = kvzalloc(inlen, GFP_KERNEL);
> if (!in || !ft->g) {
> kfree(ft->g);
> + ft->g = NULL;
> kvfree(in);
> return -ENOMEM;
> }

Reviewed-by: Tariq Toukan <tariqt@nvidia.com>