diff --git a/include/net/act_api.h b/include/net/act_api.h index 20d9e55f8564..fd03f6319e88 100644 --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -270,6 +270,25 @@ int tcf_action_check_ctrlact(int action, struct tcf_proto *tp, struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action, struct tcf_chain *newchain); +/* Range check for a control action supplied by user space. + * + * This is the same test tcf_action_check_ctrlact() applies to the primary + * control action, factored out for the *fallback* control actions + * (act_gact's TCA_GACT_PROB.paction and act_police's TCA_POLICE_RESULT), + * which must not reach tcf_action_check_ctrlact() because they have no + * goto_chain to allocate. Without it, user space can store kernel-internal + * verdicts such as TC_ACT_CONSUMED, which is TC_ACT_VALUE_MAX + 1 and is + * deliberately not part of the UAPI value range. + */ +static inline bool tcf_action_valid(int action) +{ + int opcode = TC_ACT_EXT_OPCODE(action); + + if (!opcode) + return action <= TC_ACT_VALUE_MAX; + return opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC; +} + #ifdef CONFIG_INET DECLARE_STATIC_KEY_FALSE(tcf_frag_xmit_count); #endif diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c index e949280eb800..565860cccba6 100644 --- a/net/sched/act_gact.c +++ b/net/sched/act_gact.c @@ -89,6 +89,11 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla, p_parm = nla_data(tb[TCA_GACT_PROB]); if (p_parm->ptype >= MAX_RAND) return -EINVAL; + if (!tcf_action_valid(p_parm->paction)) { + NL_SET_ERR_MSG(extack, + "invalid fallback control action"); + return -EINVAL; + } if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) { NL_SET_ERR_MSG(extack, "goto chain not allowed on fallback"); diff --git a/net/sched/act_police.c b/net/sched/act_police.c index b16468a98c55..ce08f6840ef7 100644 --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -128,6 +128,12 @@ static int tcf_police_init(struct net *net, struct nlattr *nla, if (tb[TCA_POLICE_RESULT]) { tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); + if (!tcf_action_valid(tcfp_result)) { + NL_SET_ERR_MSG(extack, + "invalid fallback control action"); + err = -EINVAL; + goto failure; + } if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) { NL_SET_ERR_MSG(extack, "goto chain not allowed on fallback");