2023-11-28 08:44:37

by Dinghao Liu

Subject: [PATCH] net/mlx5e: fix a potential double-free in fs_udp_create_groups

When kcalloc() for ft->g succeeds but kvzalloc() for in fails,
fs_udp_create_groups() will free ft->g. However, its caller
fs_udp_create_table() will free ft->g again through calling
mlx5e_destroy_flow_table(), which will lead to a double-free.
Fix this by removing the kfree(ft->g) in fs_udp_create_groups().

Fixes: 1c80bd684388 ("net/mlx5e: Introduce Flow Steering UDP API")
Signed-off-by: Dinghao Liu <[email protected]>
---
drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 1 -
1 file changed, 1 deletion(-)

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..806a5093ff63 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
@@ -153,7 +153,6 @@ static int fs_udp_create_groups(struct mlx5e_flow_table *ft, enum fs_udp_type ty
ft->g = kcalloc(MLX5E_FS_UDP_NUM_GROUPS, sizeof(*ft->g), GFP_KERNEL);
in = kvzalloc(inlen, GFP_KERNEL);
if (!in || !ft->g) {
- kfree(ft->g);
kvfree(in);
return -ENOMEM;
}
--
2.17.1

2023-11-28 09:28:43

by Tariq Toukan

Subject: Re: [PATCH] net/mlx5e: fix a potential double-free in fs_udp_create_groups

On 28/11/2023 10:43, Dinghao Liu wrote:
> When kcalloc() for ft->g succeeds but kvzalloc() for in fails,
> fs_udp_create_groups() will free ft->g. However, its caller
> fs_udp_create_table() will free ft->g again through calling
> mlx5e_destroy_flow_table(), which will lead to a double-free.
> Fix this by removing the kfree(ft->g) in fs_udp_create_groups().
>
> Fixes: 1c80bd684388 ("net/mlx5e: Introduce Flow Steering UDP API")
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/en/fs_tt_redirect.c | 1 -
> 1 file changed, 1 deletion(-)
>
> 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..806a5093ff63 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
> @@ -153,7 +153,6 @@ static int fs_udp_create_groups(struct mlx5e_flow_table *ft, enum fs_udp_type ty
> ft->g = kcalloc(MLX5E_FS_UDP_NUM_GROUPS, sizeof(*ft->g), GFP_KERNEL);
> in = kvzalloc(inlen, GFP_KERNEL);
> if (!in || !ft->g) {
> - kfree(ft->g);
> kvfree(in);
> return -ENOMEM;
> }

Same comment applies here. See the other mail thread.