On Thu, Aug 06, 2020 at 05:08:28PM +0100, Colin King wrote:
Acked by: Eli Cohen <eli@xxxxxxxxxxxx>
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The memory allocation failure checking for in and out is currently
> checking if the pointers are valid rather than the contents of what
> they point to. Hence the null check on failed memory allocations is
> incorrect. Fix this by adding the missing indirection in the check.
> Also for the default case, just set the *in and *out to null as
> these don't have any thing allocated to kfree. Finally remove the
> redundant *in and *out check as these have been already done on each
> allocation in the case statement.
>
> Addresses-Coverity: ("Null pointer dereference")
> Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 3ec44a4f0e45..55bc58e1dae9 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -867,7 +867,7 @@ static void alloc_inout(struct mlx5_vdpa_net *ndev, int cmd, void **in, int *inl
> *outlen = MLX5_ST_SZ_BYTES(qp_2rst_out);
> *in = kzalloc(*inlen, GFP_KERNEL);
> *out = kzalloc(*outlen, GFP_KERNEL);
> - if (!in || !out)
> + if (!*in || !*out)
> goto outerr;
>
> MLX5_SET(qp_2rst_in, *in, opcode, cmd);
> @@ -879,7 +879,7 @@ static void alloc_inout(struct mlx5_vdpa_net *ndev, int cmd, void **in, int *inl
> *outlen = MLX5_ST_SZ_BYTES(rst2init_qp_out);
> *in = kzalloc(*inlen, GFP_KERNEL);
> *out = kzalloc(MLX5_ST_SZ_BYTES(rst2init_qp_out), GFP_KERNEL);
> - if (!in || !out)
> + if (!*in || !*out)
> goto outerr;
>
> MLX5_SET(rst2init_qp_in, *in, opcode, cmd);
> @@ -896,7 +896,7 @@ static void alloc_inout(struct mlx5_vdpa_net *ndev, int cmd, void **in, int *inl
> *outlen = MLX5_ST_SZ_BYTES(init2rtr_qp_out);
> *in = kzalloc(*inlen, GFP_KERNEL);
> *out = kzalloc(MLX5_ST_SZ_BYTES(init2rtr_qp_out), GFP_KERNEL);
> - if (!in || !out)
> + if (!*in || !*out)
> goto outerr;
>
> MLX5_SET(init2rtr_qp_in, *in, opcode, cmd);
> @@ -914,7 +914,7 @@ static void alloc_inout(struct mlx5_vdpa_net *ndev, int cmd, void **in, int *inl
> *outlen = MLX5_ST_SZ_BYTES(rtr2rts_qp_out);
> *in = kzalloc(*inlen, GFP_KERNEL);
> *out = kzalloc(MLX5_ST_SZ_BYTES(rtr2rts_qp_out), GFP_KERNEL);
> - if (!in || !out)
> + if (!*in || !*out)
> goto outerr;
>
> MLX5_SET(rtr2rts_qp_in, *in, opcode, cmd);
> @@ -927,16 +927,15 @@ static void alloc_inout(struct mlx5_vdpa_net *ndev, int cmd, void **in, int *inl
> MLX5_SET(qpc, qpc, rnr_retry, 7);
> break;
> default:
> - goto outerr;
> + goto outerr_nullify;
> }
> - if (!*in || !*out)
> - goto outerr;
>
> return;
>
> outerr:
> kfree(*in);
> kfree(*out);
> +outerr_nullify:
> *in = NULL;
> *out = NULL;
> }
> --
> 2.27.0
>
