Re: [PATCH] net/mlx5: fix potential null dereference when enable shared FDB

[Tariq Toukan]

On 03/04/2025 17:03, Tariq Toukan wrote:
> On 03/04/2025 12:52, Charles Han(韩春超) wrote:
> > -ENXIO indicates "No such device or address". I've found that in mlx5/ 
> > core, if mlx5_get_flow_namespace() returns null, it basically returns 
> > -EOPNOTSUPP.
>
> Please do not top-post.
>
> +1.
> If namespace is not found it's due to lack of support.
>
>
> > -----邮件原件-----
> > 发件人: Przemek Kitszel <przemyslaw.kitszel@xxxxxxxxx>
> > 发送时间: 2025年4月2日 19:02
> > 收件人: Charles Han(韩春超) <hanchunchao@xxxxxxxxxx>
> > 抄送: netdev@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; linux- 
> > kernel@xxxxxxxxxxxxxxx; saeedm@xxxxxxxxxx; leon@xxxxxxxxxx; 
> > tariqt@xxxxxxxxxx; andrew+netdev@xxxxxxx; davem@xxxxxxxxxxxxx; 
> > edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; 
> > markzhang@xxxxxxxxxx; mbloch@xxxxxxxxxx
> > 主题: Re: [PATCH] net/mlx5: fix potential null dereference when enable 
> > shared FDB
> >
> > On 4/2/25 11:43, Charles Han wrote:
> > > mlx5_get_flow_namespace() may return a NULL pointer, dereferencing it
> > > without NULL check may lead to NULL dereference.
> > > Add a NULL check for ns.
> > >
> > > Fixes: db202995f503 ("net/mlx5: E-Switch, add logic to enable shared
> > > FDB")
> > > Signed-off-by: Charles Han <hanchunchao@xxxxxxxxxx>
>
> Acked-by: Tariq Toukan <tariqt@xxxxxxxxxx>

Re-visiting this...
See comment below.

> > > ---
> > >    .../net/ethernet/mellanox/mlx5/core/eswitch_offloads.c | 10 ++++++ 
> > > ++++
> > >    drivers/net/ethernet/mellanox/mlx5/core/fs_cmd.c       |  5 +++++
> > >    2 files changed, 15 insertions(+)
> > >
> > > diff --git
> > > a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
> > > b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
> > > index a6a8eea5980c..dc58e4c2d786 100644
> > > --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
> > > +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
> > > @@ -2667,6 +2667,11 @@ static int esw_set_slave_root_fdb(struct 
> > > mlx5_core_dev *master,
> > >        if (master) {
> > >            ns = mlx5_get_flow_namespace(master,
> > >                             MLX5_FLOW_NAMESPACE_FDB);
> > > +        if (!ns) {
> > > +            mlx5_core_warn(master, "Failed to get flow namespace\n");

Use esw_warn(), for all new instances.