ice: Fix memory management in ice_ethtool_fdir.c

Fix ethtool FDIR logic to not use memory after its release.
In the ice_ethtool_fdir.c file there are 2 spots where code can
refer to pointers which may be missing.

In the ice_cfg_fdir_xtrct_seq() function seg may be freed but
even then may be still used by memcpy(&tun_seg[1], seg, sizeof(*seg)).

In the ice_add_fdir_ethtool() function struct ice_fdir_fltr *input
may first fail to be added via ice_fdir_update_list_entry() but then
may be deleted by ice_fdir_update_list_entry.

Terminate in both cases when the returned value of the previous
operation is other than 0, free memory and don't use it anymore.
Reported-by: Michal Schmidt <mschmidt@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2208423
Fixes: cac2a27c ("ice: Support IPv4 Flow Director filters")
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20230721155854.1292805-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/intel/ice/ice_ethtool_fdir.c

@@ -1281,16 +1281,21 @@ ice_cfg_fdir_xtrct_seq(struct ice_pf *pf, struct ethtool_rx_flow_spec *fsp,
 				     ICE_FLOW_FLD_OFF_INVAL);
 	}
 
-	/* add filter for outer headers */
 	fltr_idx = ice_ethtool_flow_to_fltr(fsp->flow_type & ~FLOW_EXT);
+
+	assign_bit(fltr_idx, hw->fdir_perfect_fltr, perfect_filter);
+
+	/* add filter for outer headers */
 	ret = ice_fdir_set_hw_fltr_rule(pf, seg, fltr_idx,
 					ICE_FD_HW_SEG_NON_TUN);
-	if (ret == -EEXIST)
-		/* Rule already exists, free memory and continue */
-		devm_kfree(dev, seg);
-	else if (ret)
+	if (ret == -EEXIST) {
+		/* Rule already exists, free memory and count as success */
+		ret = 0;
+		goto err_exit;
+	} else if (ret) {
 		/* could not write filter, free memory */
 		goto err_exit;
+	}
 
 	/* make tunneled filter HW entries if possible */
 	memcpy(&tun_seg[1], seg, sizeof(*seg));
@@ -1305,18 +1310,13 @@ ice_cfg_fdir_xtrct_seq(struct ice_pf *pf, struct ethtool_rx_flow_spec *fsp,
 		devm_kfree(dev, tun_seg);
 	}
 
-	if (perfect_filter)
-		set_bit(fltr_idx, hw->fdir_perfect_fltr);
-	else
-		clear_bit(fltr_idx, hw->fdir_perfect_fltr);
-
 	return ret;
 
 err_exit:
 	devm_kfree(dev, tun_seg);
 	devm_kfree(dev, seg);
 
-	return -EOPNOTSUPP;
+	return ret;
 }
 
 /**
@@ -1914,7 +1914,9 @@ int ice_add_fdir_ethtool(struct ice_vsi *vsi, struct ethtool_rxnfc *cmd)
 	input->comp_report = ICE_FXD_FLTR_QW0_COMP_REPORT_SW_FAIL;
 
 	/* input struct is added to the HW filter list */
-	ice_fdir_update_list_entry(pf, input, fsp->location);
+	ret = ice_fdir_update_list_entry(pf, input, fsp->location);
+	if (ret)
+		goto release_lock;
 
 	ret = ice_fdir_write_all_fltr(pf, input, true);
 	if (ret)