2020-07-29 22:52:44

by Gustavo A. R. Silva

Subject: [PATCH][next] mlxsw: spectrum_cnt: Use flex_array_size() helper in memcpy()

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer
overflows, while at the same time makes it explicitly clear that
we are dealing witha flexible array member.

Also, remove unnecessary pointer identifier sub_pool.

Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
index 7974982533b5..b65b93a2b9bc 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
@@ -121,7 +121,6 @@ int mlxsw_sp_counter_pool_init(struct mlxsw_sp *mlxsw_sp)
{
unsigned int sub_pools_count = ARRAY_SIZE(mlxsw_sp_counter_sub_pools);
struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
- struct mlxsw_sp_counter_sub_pool *sub_pool;
struct mlxsw_sp_counter_pool *pool;
unsigned int map_size;
int err;
@@ -131,9 +130,9 @@ int mlxsw_sp_counter_pool_init(struct mlxsw_sp *mlxsw_sp)
if (!pool)
return -ENOMEM;
mlxsw_sp->counter_pool = pool;
- memcpy(pool->sub_pools, mlxsw_sp_counter_sub_pools,
- sub_pools_count * sizeof(*sub_pool));
pool->sub_pools_count = sub_pools_count;
+ memcpy(pool->sub_pools, mlxsw_sp_counter_sub_pools,
+ flex_array_size(pool, sub_pools, pool->sub_pools_count));
spin_lock_init(&pool->counter_pool_lock);
atomic_set(&pool->active_entries_count, 0);

--
2.27.0

2020-07-30 09:22:46

by Ido Schimmel

Subject: Re: [PATCH][next] mlxsw: spectrum_cnt: Use flex_array_size() helper in memcpy()

On Wed, Jul 29, 2020 at 05:58:03PM -0500, Gustavo A. R. Silva wrote:
> Make use of the flex_array_size() helper to calculate the size of a
> flexible array member within an enclosing structure.
>
> This helper offers defense-in-depth against potential integer
> overflows, while at the same time makes it explicitly clear that
> we are dealing witha flexible array member.
>
> Also, remove unnecessary pointer identifier sub_pool.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Reviewed-by: Ido Schimmel <[email protected]>
Tested-by: Ido Schimmel <[email protected]>

Thanks

2020-07-30 13:29:40

by Gustavo A. R. Silva

Subject: Re: [PATCH][next] mlxsw: spectrum_cnt: Use flex_array_size() helper in memcpy()

On 7/30/20 04:21, Ido Schimmel wrote:
> On Wed, Jul 29, 2020 at 05:58:03PM -0500, Gustavo A. R. Silva wrote:
>> Make use of the flex_array_size() helper to calculate the size of a
>> flexible array member within an enclosing structure.
>>
>> This helper offers defense-in-depth against potential integer
>> overflows, while at the same time makes it explicitly clear that
>> we are dealing witha flexible array member.
>>
>> Also, remove unnecessary pointer identifier sub_pool.
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> Reviewed-by: Ido Schimmel <[email protected]>
> Tested-by: Ido Schimmel <[email protected]>
>

Thanks, Ido.

--
Gustavo

2020-07-31 00:40:14

by David Miller

Subject: Re: [PATCH][next] mlxsw: spectrum_cnt: Use flex_array_size() helper in memcpy()

From: "Gustavo A. R. Silva" <[email protected]>
Date: Wed, 29 Jul 2020 17:58:03 -0500

> Make use of the flex_array_size() helper to calculate the size of a
> flexible array member within an enclosing structure.
>
> This helper offers defense-in-depth against potential integer
> overflows, while at the same time makes it explicitly clear that
> we are dealing witha flexible array member.
>
> Also, remove unnecessary pointer identifier sub_pool.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Applied.