Re: [PATCH v2] net/i40e: validate raw flow items before dereferencing

[Bruce Richardson <bruce.richardson@intel.com>]

On Mon, Mar 09, 2026 at 03:29:19PM +0000, Ciara Loftus wrote:
> When a RTE_FLOW_ITEM_TYPE_RAW item is used with a non-zero length,
> the spec and mask pattern pointers are dereferenced unconditionally
> in a loop, causing a segfault if either is NULL. Additionally, no
> check is made that the spec and mask have equal lengths before
> iterating, which could result in out-of-bounds access.
> 
> Add validation before the loop: reject the item if either pattern
> pointer is NULL, or if the spec and mask lengths differ.
> 
> Bugzilla ID: 1155
> Fixes: 6ced3dd72f5f ("net/i40e: support flexible payload parsing for FDIR")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>

Missed carrying-forward Anatoly's ack from v1:
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
> v2:
> * Add an additional check for spec and mask length mismatch
> ---
>  drivers/net/intel/i40e/i40e_flow.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/net/intel/i40e/i40e_flow.c b/drivers/net/intel/i40e/i40e_flow.c
> index 2374b9bbca..4624edc758 100644
> --- a/drivers/net/intel/i40e/i40e_flow.c
> +++ b/drivers/net/intel/i40e/i40e_flow.c
> @@ -2350,6 +2350,30 @@ i40e_flow_parse_fdir_pattern(struct rte_eth_dev *dev,
>  				return -rte_errno;
>  			}
>  
> +			if (raw_spec->length != 0) {
> +				if (raw_spec->pattern == NULL) {
> +					rte_flow_error_set(error, EINVAL,
> +							   RTE_FLOW_ERROR_TYPE_ITEM,
> +							   item,
> +							   "NULL RAW spec pattern");
> +					return -rte_errno;
> +				}
> +				if (raw_mask->pattern == NULL) {
> +					rte_flow_error_set(error, EINVAL,
> +							   RTE_FLOW_ERROR_TYPE_ITEM,
> +							   item,
> +							   "NULL RAW mask pattern");
> +					return -rte_errno;
> +				}
> +				if (raw_spec->length != raw_mask->length) {
> +					rte_flow_error_set(error, EINVAL,
> +							   RTE_FLOW_ERROR_TYPE_ITEM,
> +							   item,
> +							   "RAW spec and mask length mismatch");
> +					return -rte_errno;
> +				}
> +			}
> +
>  			for (i = 0; i < raw_spec->length; i++) {
>  				j = i + next_dst_off;
>  				if (j >= RTE_ETH_FDIR_MAX_FLEXLEN ||
> -- 
> 2.43.0
>