Commit 63c82997 authored Nov 09, 2018 by Jakub Kicinski Committed by David S. Miller Nov 10, 2018

net: sched: cls_flower: validate nested enc_opts_policy to avoid warning



TCA_FLOWER_KEY_ENC_OPTS and TCA_FLOWER_KEY_ENC_OPTS_MASK can only
currently contain further nested attributes, which are parsed by
hand, so the policy is never actually used resulting in a W=1
build warning:

net/sched/cls_flower.c:492:1: warning: ‘enc_opts_policy’ defined but not used [-Wunused-const-variable=]
 enc_opts_policy[TCA_FLOWER_KEY_ENC_OPTS_MAX + 1] = {

Add the validation anyway to avoid potential bugs when other
attributes are added and to make the attribute structure slightly
more clear.  Validation will also set extact to point to bad
attribute on error.

Fixes: 0a6e7778 ("net/sched: allow flower to match tunnel options")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent fbd1d524

net/sched/cls_flower.c

+13 −1

Original line number	Diff line number	Diff line
		@@ -709,11 +709,23 @@ static int fl_set_enc_opt(struct nlattr *tb, struct fl_flow_key key,
		struct netlink_ext_ack *extack)
		{
		const struct nlattr nla_enc_key, nla_opt_key, *nla_opt_msk = NULL;
		int option_len, key_depth, msk_depth = 0;
		int err, option_len, key_depth, msk_depth = 0;

		err = nla_validate_nested(tb[TCA_FLOWER_KEY_ENC_OPTS],
		TCA_FLOWER_KEY_ENC_OPTS_MAX,
		enc_opts_policy, extack);
		if (err)
		return err;

		nla_enc_key = nla_data(tb[TCA_FLOWER_KEY_ENC_OPTS]);

		if (tb[TCA_FLOWER_KEY_ENC_OPTS_MASK]) {
		err = nla_validate_nested(tb[TCA_FLOWER_KEY_ENC_OPTS_MASK],
		TCA_FLOWER_KEY_ENC_OPTS_MAX,
		enc_opts_policy, extack);
		if (err)
		return err;

		nla_opt_msk = nla_data(tb[TCA_FLOWER_KEY_ENC_OPTS_MASK]);
		msk_depth = nla_len(tb[TCA_FLOWER_KEY_ENC_OPTS_MASK]);
		}

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