2023-11-28 09:41:53

by Dinghao Liu

Subject: [PATCH] [v2] 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 setting ft->g to NULL in fs_udp_create_groups().

Fixes: 1c80bd684388 ("net/mlx5e: Introduce Flow Steering UDP API")
Signed-off-by: Dinghao Liu <[email protected]>
---

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..e1283531e0b8 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
@@ -154,6 +154,7 @@ static int fs_udp_create_groups(struct mlx5e_flow_table *ft, enum fs_udp_type ty
in = kvzalloc(inlen, GFP_KERNEL);
if (!in || !ft->g) {
kfree(ft->g);
+ ft->g = NULL;
kvfree(in);
return -ENOMEM;
}
--
2.17.1

2023-11-28 09:55:42

by Tariq Toukan

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

On 28/11/2023 11:40, 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 setting ft->g to NULL in fs_udp_create_groups().
>
> Fixes: 1c80bd684388 ("net/mlx5e: Introduce Flow Steering UDP API")
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
>
> 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..e1283531e0b8 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
> @@ -154,6 +154,7 @@ static int fs_udp_create_groups(struct mlx5e_flow_table *ft, enum fs_udp_type ty
> in = kvzalloc(inlen, GFP_KERNEL);
> if (!in || !ft->g) {
> kfree(ft->g);
> + ft->g = NULL;
> kvfree(in);
> return -ENOMEM;
> }


Thanks for your patch.
Reviewed-by: Tariq Toukan <[email protected]>

2023-11-30 17:46:17

by Simon Horman

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

On Tue, Nov 28, 2023 at 05:40:53PM +0800, 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 setting ft->g to NULL in fs_udp_create_groups().
>
> Fixes: 1c80bd684388 ("net/mlx5e: Introduce Flow Steering UDP API")
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
>
> Changelog:
>
> v2: Setting ft->g to NULL instead of removing the kfree().

Reviewed-by: Simon Horman <[email protected]>

2023-12-06 21:53:20

by Saeed Mahameed

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

On 28 Nov 17:40, 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 setting ft->g to NULL in fs_udp_create_groups().
>
>Fixes: 1c80bd684388 ("net/mlx5e: Introduce Flow Steering UDP API")
>Signed-off-by: Dinghao Liu <[email protected]>
>---
>
>Changelog:
>
>v2: Setting ft->g to NULL instead of removing the kfree().
>---

Applied to net-mlx5.

- Saeed