[PATCH] net/mlx5: fix destroying empty matchers list

[Idan Hackmon]

> -----Original Message-----
> From: Adham Masarwah <adham at nvidia.com>
> Sent: Sunday, February 27, 2022 2:33 PM
> To: Idan Hackmon <idanhac at nvidia.com>
> Subject: RE: [PATCH] net/mlx5: fix destroying empty matchers list
> 
> > Subject: [PATCH] net/mlx5: fix destroying empty matchers list
> >
> > The table remove callback function is trying to destroy the matchers
> > list associated with table entries without checking if the list is
> > valid, which causes nullptr dereference.
> > Fixed by validating the matchers list before destroying it.
> >
> > Issue can be reproduced with testpmd on Windows, when you run:
> > port close all
> >
> > Fixes: 1872635570be ("net/mlx5: make matcher list thread safe")
> > Cc: stable at dpdk.org
> >
> > Signed-off-by: Adham Masarwah <adham at nvidia.com>
> > Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
> > ---
> >  drivers/net/mlx5/mlx5_flow_dv.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/mlx5/mlx5_flow_dv.c
> > b/drivers/net/mlx5/mlx5_flow_dv.c index ef9c66eddf..baef252a7a 100644
> > --- a/drivers/net/mlx5/mlx5_flow_dv.c
> > +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> > @@ -10503,7 +10503,8 @@ flow_dv_tbl_remove_cb(void *tool_ctx, struct
> > mlx5_list_entry *entry)
> >  			tbl_data->tunnel->tunnel_id : 0,
> >  			tbl_data->group_id);
> >  	}
> > -	mlx5_list_destroy(tbl_data->matchers);
> > +	if (tbl_data->matchers)
> > +		mlx5_list_destroy(tbl_data->matchers);
> >  	mlx5_ipool_free(sh->ipool[MLX5_IPOOL_JUMP], tbl_data->idx);  }
> >
> > --
> > 2.16.1.windows.4
> 
> Acked-by: Tal Shnaiderman <talshn at nvidia.com>
Tested-by: Idan Hackmon <idanhac at nvidia.com>