Re: [PATCH] net/mlx5/core/fpga/ipsec: Fix use-after-free

From: Yuval Shaia
Date: Thu Mar 22 2018 - 14:32:59 EST


On Thu, Mar 22, 2018 at 01:03:42PM -0500, Gustavo A. R. Silva wrote:
> _rule_ is being freed and then dereferenced by accessing rule->ctx
>
> Fix this by copying the value returned by PTR_ERR(rule->ctx) into a local
> variable for its safe use after freeing _rule_
>
> Addresses-Coverity-ID: 1466041 ("Read from pointer after free")
> Fixes: 05564d0ae075 ("net/mlx5: Add flow-steering commands for FPGA IPSec implementation")
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Prefix should not be that long, a short one as this is enough.

net/mlx5: Fix use-after-free

Besides that - lgtm.

Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx>

> ---
> drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c b/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c
> index 4f15685..0f5da49 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c
> @@ -1061,8 +1061,9 @@ static int fpga_ipsec_fs_create_fte(struct mlx5_core_dev *dev,
>
> rule->ctx = mlx5_fpga_ipsec_fs_create_sa_ctx(dev, fte, is_egress);
> if (IS_ERR(rule->ctx)) {
> + int err = PTR_ERR(rule->ctx);
> kfree(rule);
> - return PTR_ERR(rule->ctx);
> + return err;
> }
>
> rule->fte = fte;
> --
> 2.7.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html