From 5c7539781d392629fb40b04aad9a1f197b66cd01 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Fri, 4 Aug 2006 23:03:53 -0700 Subject: [PATCH] [IPV4]: Convert address addition to new netlink api Adds rtm_to_ifaddr() transforming a netlink message to a struct in_ifaddr. Fixes various unvalidated netlink attributes causing memory corruptions when left empty by userspace applications. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- net/ipv4/devinet.c | 108 +++++++++++++++++++++++++++++++-------------- 1 file changed, 75 insertions(+), 33 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 9f3ffbec3296..6b297c8697e6 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -62,6 +62,7 @@ #include #include #include +#include struct ipv4_devconf ipv4_devconf = { .accept_redirects = 1, @@ -78,6 +79,14 @@ static struct ipv4_devconf ipv4_devconf_dflt = { .accept_source_route = 1, }; +static struct nla_policy ifa_ipv4_policy[IFA_MAX+1] __read_mostly = { + [IFA_LOCAL] = { .type = NLA_U32 }, + [IFA_ADDRESS] = { .type = NLA_U32 }, + [IFA_BROADCAST] = { .type = NLA_U32 }, + [IFA_ANYCAST] = { .type = NLA_U32 }, + [IFA_LABEL] = { .type = NLA_STRING }, +}; + static void rtmsg_ifa(int event, struct in_ifaddr *); static BLOCKING_NOTIFIER_HEAD(inetaddr_chain); @@ -451,57 +460,90 @@ out: return -EADDRNOTAVAIL; } -static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) +static struct in_ifaddr *rtm_to_ifaddr(struct nlmsghdr *nlh) { - struct rtattr **rta = arg; + struct nlattr *tb[IFA_MAX+1]; + struct in_ifaddr *ifa; + struct ifaddrmsg *ifm; struct net_device *dev; struct in_device *in_dev; - struct ifaddrmsg *ifm = NLMSG_DATA(nlh); - struct in_ifaddr *ifa; - int rc = -EINVAL; + int err = -EINVAL; - ASSERT_RTNL(); + err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy); + if (err < 0) + goto errout; - if (ifm->ifa_prefixlen > 32 || !rta[IFA_LOCAL - 1]) - goto out; + ifm = nlmsg_data(nlh); + if (ifm->ifa_prefixlen > 32 || tb[IFA_LOCAL] == NULL) + goto errout; - rc = -ENODEV; - if ((dev = __dev_get_by_index(ifm->ifa_index)) == NULL) - goto out; + dev = __dev_get_by_index(ifm->ifa_index); + if (dev == NULL) { + err = -ENODEV; + goto errout; + } - rc = -ENOBUFS; - if ((in_dev = __in_dev_get_rtnl(dev)) == NULL) { + in_dev = __in_dev_get_rtnl(dev); + if (in_dev == NULL) { in_dev = inetdev_init(dev); - if (!in_dev) - goto out; + if (in_dev == NULL) { + err = -ENOBUFS; + goto errout; + } } - if ((ifa = inet_alloc_ifa()) == NULL) - goto out; + ifa = inet_alloc_ifa(); + if (ifa == NULL) { + /* + * A potential indev allocation can be left alive, it stays + * assigned to its device and is destroy with it. + */ + err = -ENOBUFS; + goto errout; + } + + in_dev_hold(in_dev); + + if (tb[IFA_ADDRESS] == NULL) + tb[IFA_ADDRESS] = tb[IFA_LOCAL]; - if (!rta[IFA_ADDRESS - 1]) - rta[IFA_ADDRESS - 1] = rta[IFA_LOCAL - 1]; - memcpy(&ifa->ifa_local, RTA_DATA(rta[IFA_LOCAL - 1]), 4); - memcpy(&ifa->ifa_address, RTA_DATA(rta[IFA_ADDRESS - 1]), 4); ifa->ifa_prefixlen = ifm->ifa_prefixlen; ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen); - if (rta[IFA_BROADCAST - 1]) - memcpy(&ifa->ifa_broadcast, - RTA_DATA(rta[IFA_BROADCAST - 1]), 4); - if (rta[IFA_ANYCAST - 1]) - memcpy(&ifa->ifa_anycast, RTA_DATA(rta[IFA_ANYCAST - 1]), 4); ifa->ifa_flags = ifm->ifa_flags; ifa->ifa_scope = ifm->ifa_scope; - in_dev_hold(in_dev); - ifa->ifa_dev = in_dev; - if (rta[IFA_LABEL - 1]) - rtattr_strlcpy(ifa->ifa_label, rta[IFA_LABEL - 1], IFNAMSIZ); + ifa->ifa_dev = in_dev; + + ifa->ifa_local = nla_get_u32(tb[IFA_LOCAL]); + ifa->ifa_address = nla_get_u32(tb[IFA_ADDRESS]); + + if (tb[IFA_BROADCAST]) + ifa->ifa_broadcast = nla_get_u32(tb[IFA_BROADCAST]); + + if (tb[IFA_ANYCAST]) + ifa->ifa_anycast = nla_get_u32(tb[IFA_ANYCAST]); + + if (tb[IFA_LABEL]) + nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ); else memcpy(ifa->ifa_label, dev->name, IFNAMSIZ); - rc = inet_insert_ifa(ifa); -out: - return rc; + return ifa; + +errout: + return ERR_PTR(err); +} + +static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) +{ + struct in_ifaddr *ifa; + + ASSERT_RTNL(); + + ifa = rtm_to_ifaddr(nlh); + if (IS_ERR(ifa)) + return PTR_ERR(ifa); + + return inet_insert_ifa(ifa); } /* -- 2.39.5