Re: [PATCH net-next] netlink: add missing length check of rtnl msg
From: Thomas Graf <tgraf@suug.ch>
Date: 2013-03-25 23:12:07
On 03/26/13 at 01:22am, Hong Zhiguo wrote:
quoted hunk ↗ jump to hunk
protocol = TC_H_MIN(t->tcm_info);diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 0bbce22..b30a988 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;@@ -985,6 +985,9 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n) if ((n->nlmsg_type != RTM_GETQDISC) && !capable(CAP_NET_ADMIN)) return -EPERM; + if (nlmsg_len(n) < sizeof(*tcm)) + return -EINVAL; + dev = __dev_get_by_index(net, tcm->tcm_ifindex); if (!dev) return -ENODEV;
What do you think about moving the nlmsg_parse() call from below here to before __dev_get_by_index()? It also verifies the header length and it's how other netlink code verifies the message type specific header as well.
quoted hunk ↗ jump to hunk
if (err < 0)@@ -1051,6 +1055,9 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n) if (!capable(CAP_NET_ADMIN)) return -EPERM; + if (nlmsg_len(n) < sizeof(*tcm)) + return -EINVAL; +
Same here.
quoted hunk ↗ jump to hunk
replay: /* Reinit, just in case something touches this. */ tcm = nlmsg_data(n);@@ -1382,14 +1389,17 @@ 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; + if (nlmsg_len(n) < sizeof(*tcm)) + return -EINVAL; + dev = __dev_get_by_index(net, tcm->tcm_ifindex); if (!dev) return -ENODEV;
And here.