[PATCH v2 net-next] netlink: have length check of rtnl msg before deref
From: Hong Zhiguo <hidden>
Date: 2013-03-26 03:36:50
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
When the legacy array rtm_min still exists, the length check within these functions is covered by rtm_min[RTM_NEWTFILTER], rtm_min[RTM_NEWQDISC] and rtm_min[RTM_NEWTCLASS]. But after Thomas Graf removed rtm_min several days ago, these checks are missing. Other doit functions should be OK. Signed-off-by: Hong Zhiguo <redacted> --- net/sched/cls_api.c | 9 +++++---- net/sched/sch_api.c | 36 +++++++++++++++++++++--------------- 2 files changed, 26 insertions(+), 19 deletions(-)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 9a04b98..9d71d4d 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c@@ -141,7 +141,12 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n) if ((n->nlmsg_type != RTM_GETTFILTER) && !capable(CAP_NET_ADMIN)) return -EPERM; + replay: + err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL); + if (err < 0) + return err; + t = nlmsg_data(n); protocol = TC_H_MIN(t->tcm_info); prio = TC_H_MAJ(t->tcm_info);
@@ -164,10 +169,6 @@ replay: if (dev == NULL) return -ENODEV; - err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL); - if (err < 0) - return err; - /* Find qdisc */ if (!parent) { q = dev->qdisc;
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 0bbce22..d7468ba 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c@@ -977,7 +977,7 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n) struct tcmsg *tcm = nlmsg_data(n); struct nlattr *tca[TCA_MAX + 1]; struct net_device *dev; - u32 clid = tcm->tcm_parent; + u32 clid; struct Qdisc *q = NULL; struct Qdisc *p = NULL; int err;
@@ -985,14 +985,15 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n) if ((n->nlmsg_type != RTM_GETQDISC) && !capable(CAP_NET_ADMIN)) return -EPERM; - dev = __dev_get_by_index(net, tcm->tcm_ifindex); - if (!dev) - return -ENODEV; - err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); if (err < 0) return err; + dev = __dev_get_by_index(net, tcm->tcm_ifindex); + if (!dev) + return -ENODEV; + + clid = tcm->tcm_parent; if (clid) { if (clid != TC_H_ROOT) { if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) {
@@ -1053,6 +1054,10 @@ 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); + if (err < 0) + return err; + tcm = nlmsg_data(n); clid = tcm->tcm_parent; q = p = NULL;
@@ -1061,9 +1066,6 @@ replay: if (!dev) return -ENODEV; - err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); - if (err < 0) - return err; if (clid) { if (clid != TC_H_ROOT) {
@@ -1382,22 +1384,22 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n) const struct Qdisc_class_ops *cops; unsigned long cl = 0; unsigned long new_cl; - u32 portid = tcm->tcm_parent; - u32 clid = tcm->tcm_handle; - u32 qid = TC_H_MAJ(clid); + u32 portid; + u32 clid; + u32 qid; int err; if ((n->nlmsg_type != RTM_GETTCLASS) && !capable(CAP_NET_ADMIN)) return -EPERM; - dev = __dev_get_by_index(net, tcm->tcm_ifindex); - if (!dev) - return -ENODEV; - err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL); if (err < 0) return err; + dev = __dev_get_by_index(net, tcm->tcm_ifindex); + if (!dev) + return -ENODEV; + /* parent == TC_H_UNSPEC - unspecified parent. parent == TC_H_ROOT - class is root, which has no parent.
@@ -1413,6 +1415,10 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n) /* Step 1. Determine qdisc handle X:0 */ + portid = tcm->tcm_parent; + clid = tcm->tcm_handle; + qid = TC_H_MAJ(clid); + if (portid != TC_H_ROOT) { u32 qid1 = TC_H_MAJ(portid);
--
1.7.10.4