netlink: compare policy more accurately (899b07c5) · Commits · 戴 / test

The maxtype is really an integral part of the policy, and while we haven't gotten into a situation yet where this happens, it seems that some developer might eventually have two places pointing to identical policies, with different maxattr to exclude some attrs in one of the places. Even if not, it's really the right thing to compare both since the two data items fundamentally belong together. v2: - also do the proper comparison in get_policy_idx() Signed-off-by:

Johannes Berg <johannes.berg@intel.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/netlink/policy.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -35,7 +35,8 @@ static int add_policy(struct netlink_policy_dump_state **statep,
		return 0;

		for (i = 0; i < state->n_alloc; i++) {
		if (state->policies[i].policy == policy)
		if (state->policies[i].policy == policy &&
		state->policies[i].maxtype == maxtype)
		return 0;

		if (!state->policies[i].policy) {
		@@ -63,12 +64,14 @@ static int add_policy(struct netlink_policy_dump_state **statep,
		}

		static unsigned int get_policy_idx(struct netlink_policy_dump_state *state,
		const struct nla_policy *policy)
		const struct nla_policy *policy,
		unsigned int maxtype)
		{
		unsigned int i;

		for (i = 0; i < state->n_alloc; i++) {
		if (state->policies[i].policy == policy)
		if (state->policies[i].policy == policy &&
		state->policies[i].maxtype == maxtype)
		return i;
		}

		@@ -182,7 +185,8 @@ send_attribute:
		type = NL_ATTR_TYPE_NESTED_ARRAY;
		if (pt->nested_policy && pt->len &&
		(nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_IDX,
		get_policy_idx(state, pt->nested_policy)) \|\|
		get_policy_idx(state, pt->nested_policy,
		pt->len)) \|\|
		nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE,
		pt->len)))
		goto nla_put_failure;

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