i40e: add max boundary check for VF filters

JIRA: https://issues.redhat.com/browse/RHEL-123809
CVE: CVE-2025-39968

commit cb79fa7
Author: Lukasz Czapnik <lukasz.czapnik@intel.com>
Date:   Wed Aug 13 12:45:16 2025 +0200

    i40e: add max boundary check for VF filters

    There is no check for max filters that VF can request. Add it.

    Fixes: e284fc2 ("i40e: Add and delete cloud filter")
    Cc: stable@vger.kernel.org
    Signed-off-by: Lukasz Czapnik <lukasz.czapnik@intel.com>
    Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
    Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
    Reviewed-by: Simon Horman <horms@kernel.org>
    Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
    Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

Author: michich

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -3908,6 +3908,8 @@ static int i40e_vc_del_cloud_filter(struct i40e_vf *vf, u8 *msg)
 				       aq_ret);
 }
 
+#define I40E_MAX_VF_CLOUD_FILTER 0xFF00
+
 /**
  * i40e_vc_add_cloud_filter
  * @vf: pointer to the VF info
@@ -3947,6 +3949,14 @@ static int i40e_vc_add_cloud_filter(struct i40e_vf *vf, u8 *msg)
 		goto err_out;
 	}
 
+	if (vf->num_cloud_filters >= I40E_MAX_VF_CLOUD_FILTER) {
+		dev_warn(&pf->pdev->dev,
+			 "VF %d: Max number of filters reached, can't apply cloud filter\n",
+			 vf->vf_id);
+		aq_ret = -ENOSPC;
+		goto err_out;
+	}
+
 	cfilter = kzalloc(sizeof(*cfilter), GFP_KERNEL);
 	if (!cfilter) {
 		aq_ret = -ENOMEM;