| Message ID | 20190617100327.24796-3-ldir@darbyshire-bryant.me.uk |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next,1/2] net: sched: act_ctinfo: fix action creation | expand |
diff --git a/net/sched/act_ctinfo.c b/net/sched/act_ctinfo.c index 2c17f6843107..10eb2bb99861 100644 --- a/net/sched/act_ctinfo.c +++ b/net/sched/act_ctinfo.c @@ -141,7 +141,8 @@ static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a, } static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { - [TCA_CTINFO_ACT] = { .len = sizeof(struct + [TCA_CTINFO_ACT] = { .type = NLA_EXACT_LEN, + .len = sizeof(struct tc_ctinfo) }, [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 },
Fix nla_policy definition by specifying an exact length type attribute to CTINFO action paraneter block structure. Without this change, netlink parsing will fail validation and the action will not be instantiated. 8cb081746c03 ("netlink: make validation more configurable for future") introduced much stricter checking to attributes being passed via netlink. Existing actions were updated to use less restrictive deprecated versions of nla_parse_nested. As a new module, act_ctinfo should be designed to use the strict checking model otherwise, well, what was the point of implementing it. Confession time: Until very recently, development of this module has been done on 'net-next' tree to 'clean compile' level with run-time testing on backports to 4.14 & 4.19 kernels under openwrt. This is how I managed to miss the run-time impacts of the new strict nla_parse_nested function. I hopefully have learned something from this (glances toward laptop running a net-next kernel) There is however a still outstanding implication on iproute2 user space in that it needs to be told to pass nested netlink messages with the nested attribute actually set. So even with this kernel fix to do things correctly you still cannot instantiate a new 'strict' nla_parse_nested based action such as act_ctinfo with iproute2's tc. Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> --- net/sched/act_ctinfo.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)