From: Jiri Pirko <jiri@mellanox.com>

Date: Sat, 20 May 2017 15:01:31 +0200

Subject: net/sched: properly assign RCU pointer in tcf_chain_tp_insert/remove

Patch-mainline: v4.13-rc1

Git-commit: 31efcc250a1dea96edca6595a9639d898cf99ae5

References: bsc#1056787

*p_filter_chain is rcu-dereferenced on reader path. So here in writer,

property assign the pointer.

Fixes: 2190d1d0944f ("net: sched: introduce helpers to work with filter chains")

Signed-off-by: Jiri Pirko <jiri@mellanox.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>

---

 net/sched/cls_api.c |    4 ++--

 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/sched/cls_api.c

+++ b/net/sched/cls_api.c

@@ -351,7 +351,7 @@ static void tcf_chain_tp_insert(struct t

 {

 	if (chain->p_filter_chain &&

 	    *chain_info->pprev == chain->filter_chain)

-		*chain->p_filter_chain = tp;

+		rcu_assign_pointer(*chain->p_filter_chain, tp);

 	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));

 	rcu_assign_pointer(*chain_info->pprev, tp);

 }

@@ -363,7 +363,7 @@ static void tcf_chain_tp_remove(struct t

 	struct tcf_proto *next = rtnl_dereference(chain_info->next);

 	if (chain->p_filter_chain && tp == chain->filter_chain)

-		*chain->p_filter_chain = next;

+		RCU_INIT_POINTER(*chain->p_filter_chain, next);

 	RCU_INIT_POINTER(*chain_info->pprev, next);

 }