From 0bcbc92629044b5403719f77fb015e9005b1f504 Mon Sep 17 00:00:00 2001 From: YOSHIFUJI Hideaki Date: Tue, 24 Apr 2007 14:58:30 -0700 Subject: [PATCH] [IPV6]: Disallow RH0 by default. A security issue is emerging. Disallow Routing Header Type 0 by default as we have been doing for IPv4. Note: We allow RH2 by default because it is harmless. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 9 ++++++ include/linux/ipv6.h | 3 ++ include/linux/sysctl.h | 1 + net/ipv6/addrconf.c | 11 +++++++ net/ipv6/exthdrs.c | 40 ++++++++++++++++++++++---- 5 files changed, 58 insertions(+), 6 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index d3aae1f9b4c1..702d1d8dd04a 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -851,6 +851,15 @@ accept_redirects - BOOLEAN Functional default: enabled if local forwarding is disabled. disabled if local forwarding is enabled. +accept_source_route - INTEGER + Accept source routing (routing extension header). + + > 0: Accept routing header. + = 0: Accept only routing header type 2. + < 0: Do not accept routing header. + + Default: 0 + autoconf - BOOLEAN Autoconfigure addresses using Prefix Information in Router Advertisements. diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index f8241130f5ea..713eb5eaa81f 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -177,6 +177,7 @@ struct ipv6_devconf { #endif #endif __s32 proxy_ndp; + __s32 accept_source_route; void *sysctl; }; @@ -205,6 +206,8 @@ enum { DEVCONF_RTR_PROBE_INTERVAL, DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN, DEVCONF_PROXY_NDP, + __DEVCONF_OPTIMISTIC_DAD, + DEVCONF_ACCEPT_SOURCE_ROUTE, DEVCONF_MAX }; diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 2c5fb38d9392..9a8970bf99a6 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -580,6 +580,7 @@ enum { NET_IPV6_RTR_PROBE_INTERVAL=21, NET_IPV6_ACCEPT_RA_RT_INFO_MAX_PLEN=22, NET_IPV6_PROXY_NDP=23, + NET_IPV6_ACCEPT_SOURCE_ROUTE=25, __NET_IPV6_MAX }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 7552663aa125..452a82ce4796 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -172,6 +172,7 @@ struct ipv6_devconf ipv6_devconf __read_mostly = { #endif #endif .proxy_ndp = 0, + .accept_source_route = 0, /* we do not accept RH0 by default. */ }; static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { @@ -203,6 +204,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { #endif #endif .proxy_ndp = 0, + .accept_source_route = 0, /* we do not accept RH0 by default. */ }; /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */ @@ -3356,6 +3358,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, #endif #endif array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp; + array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route; } static inline size_t inet6_if_nlmsg_size(void) @@ -3883,6 +3886,14 @@ static struct addrconf_sysctl_table .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = NET_IPV6_ACCEPT_SOURCE_ROUTE, + .procname = "accept_source_route", + .data = &ipv6_devconf.accept_source_route, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, { .ctl_name = 0, /* sentinel */ } diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 28e0c6568272..6ed6a8cd6a68 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -362,10 +362,27 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp) struct inet6_skb_parm *opt = IP6CB(skb); struct in6_addr *addr = NULL; struct in6_addr daddr; + struct inet6_dev *idev; int n, i; - struct ipv6_rt_hdr *hdr; struct rt0_hdr *rthdr; + int accept_source_route = ipv6_devconf.accept_source_route; + + if (accept_source_route < 0 || + ((idev = in6_dev_get(skb->dev)) == NULL)) { + kfree_skb(skb); + return -1; + } + if (idev->cnf.accept_source_route < 0) { + in6_dev_put(idev); + kfree_skb(skb); + return -1; + } + + if (accept_source_route > idev->cnf.accept_source_route) + accept_source_route = idev->cnf.accept_source_route; + + in6_dev_put(idev); if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { @@ -377,6 +394,22 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp) hdr = (struct ipv6_rt_hdr *) skb->h.raw; + switch (hdr->type) { +#ifdef CONFIG_IPV6_MIP6 + break; +#endif + case IPV6_SRCRT_TYPE_0: + if (accept_source_route <= 0) + break; + kfree_skb(skb); + return -1; + default: + IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), + IPSTATS_MIB_INHDRERRORS); + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw); + return -1; + } + if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr) || skb->pkt_type != PACKET_HOST) { IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), @@ -434,11 +467,6 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp) } break; #endif - default: - IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), - IPSTATS_MIB_INHDRERRORS); - icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw); - return -1; } /*