Re: [dpdk-dev] [PATCH] net/ipn3ke: fix null pointer dereference

["Xu, Rosen" <rosen.xu@intel.com>]

> -----Original Message-----
> From: Pei, Andy
> Sent: Thursday, May 23, 2019 12:31
> To: dev@dpdk.org
> Cc: Pei, Andy <andy.pei@intel.com>; Xu, Rosen <rosen.xu@intel.com>;
> stable@dpdk.org
> Subject: [PATCH] net/ipn3ke: fix null pointer dereference
> 
> In current code, scenario may happens that when function
> ipn3ke_hw_tm_node_wr is called, struct ipn3ke_tm_node n has a NULL
> element parent_node, however, the element parent_node of struct
> ipn3ke_tm_node n is used in an invalid way.
> After applying this patch,
> this null pointer dereference is avoided.
> 
> Coverity issue: 337921
> Fixes: c820468ac99c ("net/ipn3ke: support TM")
> Cc: rosen.xu@intel.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Andy Pei <andy.pei@intel.com>
> ---
>  drivers/net/ipn3ke/ipn3ke_tm.c | 43 +++++++++++++++++++++++---------------
> ----
>  1 file changed, 24 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/net/ipn3ke/ipn3ke_tm.c
> b/drivers/net/ipn3ke/ipn3ke_tm.c index 4bcf3aa..30a3dfd 100644
> --- a/drivers/net/ipn3ke/ipn3ke_tm.c
> +++ b/drivers/net/ipn3ke/ipn3ke_tm.c
> @@ -1579,7 +1579,8 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
> 
>  static int
>  ipn3ke_hw_tm_node_wr(struct ipn3ke_hw *hw,
> -				struct ipn3ke_tm_node *n)
> +	struct ipn3ke_tm_node *n,
> +	struct ipn3ke_tm_node *parent_node)
>  {
>  	uint32_t level;
> 
> @@ -1650,11 +1651,12 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
>  		/**
>  		 * Configure Map
>  		 */
> -		IPN3KE_MASK_WRITE_REG(hw,
> -				IPN3KE_QOS_MAP_L2_X,
> -				n->node_index,
> -				n->parent_node->node_index,
> -				IPN3KE_QOS_MAP_L2_MASK);
> +		if (parent_node)
> +			IPN3KE_MASK_WRITE_REG(hw,
> +					IPN3KE_QOS_MAP_L2_X,
> +					n->node_index,
> +					parent_node->node_index,
> +					IPN3KE_QOS_MAP_L2_MASK);
> 
>  		break;
>  	case IPN3KE_TM_NODE_LEVEL_COS:
> @@ -1707,11 +1709,12 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
>  					0x80000000))
>  			;
> 
> -		IPN3KE_MASK_WRITE_REG(hw,
> -			IPN3KE_QM_UID_CONFIG_DATA,
> -			0,
> -			(1 << 8 | n->parent_node->parent_node-
> >node_index),
> -			0x1FF);
> +		if (parent_node && parent_node->parent_node)
> +			IPN3KE_MASK_WRITE_REG(hw,
> +				IPN3KE_QM_UID_CONFIG_DATA,
> +				0,
> +				(1 << 8 | parent_node->parent_node-
> >node_index),
> +				0x1FF);
> 
>  		IPN3KE_MASK_WRITE_REG(hw,
>  				IPN3KE_QM_UID_CONFIG_CTRL,
> @@ -1728,11 +1731,12 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
>  		/**
>  		 * Configure Map
>  		 */
> -		IPN3KE_MASK_WRITE_REG(hw,
> -				IPN3KE_QOS_MAP_L1_X,
> -				n->node_index,
> -				n->parent_node->node_index,
> -				IPN3KE_QOS_MAP_L1_MASK);
> +		if (parent_node)
> +			IPN3KE_MASK_WRITE_REG(hw,
> +					IPN3KE_QOS_MAP_L1_X,
> +					n->node_index,
> +					parent_node->node_index,
> +					IPN3KE_QOS_MAP_L1_MASK);
> 
>  		break;
>  	default:
> @@ -1772,7 +1776,8 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
>  						NULL,
>  						rte_strerror(EINVAL));
>  		}
> -		ipn3ke_hw_tm_node_wr(hw, n);
> +		parent_node = n->parent_node;
> +		ipn3ke_hw_tm_node_wr(hw, n, parent_node);
>  	}
> 
>  	nl = &tm->h.vt_commit_node_list;
> @@ -1802,7 +1807,7 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
>  						NULL,
>  						rte_strerror(EINVAL));
>  		}
> -		ipn3ke_hw_tm_node_wr(hw, n);
> +		ipn3ke_hw_tm_node_wr(hw, n, parent_node);
>  	}
> 
>  	nl = &tm->h.cos_commit_node_list;
> @@ -1836,7 +1841,7 @@ struct ipn3ke_tm_shaper_params_range_type
> ipn3ke_tm_shaper_params_rang[] = {
>  						NULL,
>  						rte_strerror(EINVAL));
>  		}
> -		ipn3ke_hw_tm_node_wr(hw, n);
> +		ipn3ke_hw_tm_node_wr(hw, n, parent_node);
>  	}
> 
>  	return 0;
> --
> 1.8.3.1

Acked-by: Rosen Xu <rosen.xu@intel.com>