net: sched: fix clsact init error path
Since in qdisc_create, the destroy op is called when init fails, we
don't do cleanup in init and leave it up to destroy.
This fixes use-after-free when trying to put already freed block.
Fixes: 6e40cf2d4dee ("net: sched: use extended variants of block_get/put in ingress and clsact qdiscs")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index f40256a..b91ea03 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -351,6 +351,8 @@
{
struct tcf_chain *chain;
+ if (!block)
+ return;
/* Hold a refcnt for all chains, except 0, so that they don't disappear
* while we are iterating.
*/
@@ -377,8 +379,6 @@
{
struct tcf_block_ext_info ei = {0, };
- if (!block)
- return;
tcf_block_put_ext(block, block->q, &ei);
}
diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
index 5ecc38f..5e1cd2e 100644
--- a/net/sched/sch_ingress.c
+++ b/net/sched/sch_ingress.c
@@ -190,7 +190,7 @@
err = tcf_block_get_ext(&q->egress_block, sch, &q->egress_block_info);
if (err)
- goto err_egress_block_get;
+ return err;
net_inc_ingress_queue();
net_inc_egress_queue();
@@ -198,10 +198,6 @@
sch->flags |= TCQ_F_CPUSTATS;
return 0;
-
-err_egress_block_get:
- tcf_block_put_ext(q->ingress_block, sch, &q->ingress_block_info);
- return err;
}
static void clsact_destroy(struct Qdisc *sch)