From de179c8c12e9e5a292269fa59e7c26ca797dc7bf Mon Sep 17 00:00:00 2001 From: Hong zhi guo Date: Mon, 25 Mar 2013 17:36:33 +0000 Subject: [PATCH] netlink: have length check of rtnl msg before deref 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 Acked-by: Thomas Graf Signed-off-by: David S. Miller --- 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 9a04b981bc13..9d71d4ded53b 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 0bbce229ac69..d7468baf890e 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); -- 2.20.1