releases/4.19.35/net-sched-fix-get-helper-of-the-matchall-cls.patch

   1 From 2e627787f888b74c68e395afb99fc532bf44dedc Mon Sep 17 00:00:00 2001
   2 From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
   3 Date: Thu, 28 Mar 2019 10:35:06 +0100
   4 Subject: net/sched: fix ->get helper of the matchall cls
   5
   6 [ Upstream commit 0db6f8befc32c68bb13d7ffbb2e563c79e913e13 ]
   7
   8 It returned always NULL, thus it was never possible to get the filter.
   9
  10 Example:
  11 $ ip link add foo type dummy
  12 $ ip link add bar type dummy
  13 $ tc qdisc add dev foo clsact
  14 $ tc filter add dev foo protocol all pref 1 ingress handle 1234 \
  15         matchall action mirred ingress mirror dev bar
  16
  17 Before the patch:
  18 $ tc filter get dev foo protocol all pref 1 ingress handle 1234 matchall
  19 Error: Specified filter handle not found.
  20 We have an error talking to the kernel
  21
  22 After:
  23 $ tc filter get dev foo protocol all pref 1 ingress handle 1234 matchall
  24 filter ingress protocol all pref 1 matchall chain 0 handle 0x4d2
  25   not_in_hw
  26         action order 1: mirred (Ingress Mirror to device bar) pipe
  27         index 1 ref 1 bind 1
  28
  29 CC: Yotam Gigi <yotamg@mellanox.com>
  30 CC: Jiri Pirko <jiri@mellanox.com>
  31 Fixes: fd62d9f5c575 ("net/sched: matchall: Fix configuration race")
  32 Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
  33 Signed-off-by: David S. Miller <davem@davemloft.net>
  34 Signed-off-by: Sasha Levin <sashal@kernel.org>
  35 ---
  36  net/sched/cls_matchall.c | 5 +++++
  37  1 file changed, 5 insertions(+)
  38
  39 diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
  40 index 856fa79d4ffd..621bc1d5b057 100644
  41 --- a/net/sched/cls_matchall.c
  42 +++ b/net/sched/cls_matchall.c
  43 @@ -126,6 +126,11 @@ static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
  44
  45  static void *mall_get(struct tcf_proto *tp, u32 handle)
  46  {
  47 +       struct cls_mall_head *head = rtnl_dereference(tp->root);
  48 +
  49 +       if (head && head->handle == handle)
  50 +               return head;
  51 +
  52         return NULL;
  53  }
  54
  55 --
  56 2.19.1
  57