On 08/05/2019 08:17, Dan Carpenter wrote:
> Hello Pieter Jansen van Vuuren,
>
> The patch f00cbf196814: "net/sched: use the hardware intermediate
> representation for matchall" from May 4, 2019, leads to the following
> static checker warning:
>
> net/sched/cls_matchall.c:317 mall_reoffload()
> error: double free of 'cls_mall.rule'
>
> net/sched/cls_matchall.c
> 286 static int mall_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
> 287 void *cb_priv, struct netlink_ext_ack *extack)
> 288 {
> 289 struct cls_mall_head *head = rtnl_dereference(tp->root);
> 290 struct tc_cls_matchall_offload cls_mall = {};
> 291 struct tcf_block *block = tp->chain->block;
> 292 int err;
> 293
> 294 if (tc_skip_hw(head->flags))
> 295 return 0;
> 296
> 297 cls_mall.rule = flow_rule_alloc(tcf_exts_num_actions(&head->exts));
> 298 if (!cls_mall.rule)
> 299 return -ENOMEM;
> 300
> 301 tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, block,
> 302 extack);
> 303 cls_mall.command = add ?
> 304 TC_CLSMATCHALL_REPLACE : TC_CLSMATCHALL_DESTROY;
> 305 cls_mall.cookie = (unsigned long)head;
> 306
> 307 err = tc_setup_flow_action(&cls_mall.rule->action, &head->exts);
> 308 if (err) {
> 309 kfree(cls_mall.rule);
> ^^^^^^^^^^^^^^^^^^^
> 310 if (add && tc_skip_sw(head->flags)) {
> 311 NL_SET_ERR_MSG_MOD(extack, "Failed to setup flow action");
> 312 return err;
> 313 }
>
> My guess is that there should be a "return err;" here?
Thank you. Yes, I think this should be "return 0;" instead of "return err;"
