From 8b4c3cdd9dd8290343ce959a132d3b334062c5b9 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 3 Oct 2018 15:05:36 -0700 Subject: [PATCH] net: sched: Add policy validation for tc attributes A number of TC attributes are processed without proper validation (e.g., length checks). Add a tca policy for all input attributes and use when invoking nlmsg_parse. The 2 Fixes tags below cover the latest additions. The other attributes are a string (KIND), nested attribute (OPTIONS which does seem to have validation in most cases), for dumps only or a flag. Fixes: 5bc1701881e39 ("net: sched: introduce multichain support for filters") Fixes: d47a6b0e7c492 ("net: sched: introduce ingress/egress block index attributes for qdisc") Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/sched/sch_api.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 98541c6399db..85e73f48e48f 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1311,6 +1311,18 @@ check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) * Delete/get qdisc. */ +const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { + [TCA_KIND] = { .type = NLA_STRING }, + [TCA_OPTIONS] = { .type = NLA_NESTED }, + [TCA_RATE] = { .type = NLA_BINARY, + .len = sizeof(struct tc_estimator) }, + [TCA_STAB] = { .type = NLA_NESTED }, + [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, + [TCA_CHAIN] = { .type = NLA_U32 }, + [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, + [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, +}; + static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, struct netlink_ext_ack *extack) { @@ -1327,7 +1339,8 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; - err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL, extack); + err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy, + extack); if (err < 0) return err; @@ -1411,7 +1424,8 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, replay: /* Reinit, just in case something touches this. */ - err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL, extack); + err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy, + extack); if (err < 0) return err; @@ -1645,7 +1659,8 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) idx = 0; ASSERT_RTNL(); - err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, NULL, NULL); + err = nlmsg_parse(nlh, sizeof(struct tcmsg), tca, TCA_MAX, + rtm_tca_policy, NULL); if (err < 0) return err; @@ -1864,7 +1879,8 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; - err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL, extack); + err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, rtm_tca_policy, + extack); if (err < 0) return err;