From 1442f6f7c1b77de1c508318164a527e240c24a4d Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 20 Apr 2017 11:44:16 +0200 Subject: ipvs: explicitly forbid ipv6 service/dest creation if ipv6 mod is disabled When creating a new ipvs service, ipv6 addresses are always accepted if CONFIG_IP_VS_IPV6 is enabled. On dest creation the address family is not explicitly checked. This allows the user-space to configure ipvs services even if the system is booted with ipv6.disable=1. On specific configuration, ipvs can try to call ipv6 routing code at setup time, causing the kernel to oops due to fib6_rules_ops being NULL. This change addresses the issue adding a check for the ipv6 module being enabled while validating ipv6 service operations and adding the same validation for dest operations. According to git history, this issue is apparently present since the introduction of ipv6 support, and the oops can be triggered since commit 09571c7ae30865ad ("IPVS: Add function to determine if IPv6 address is local") Fixes: 09571c7ae30865ad ("IPVS: Add function to determine if IPv6 address is local") Signed-off-by: Paolo Abeni Acked-by: Julian Anastasov Signed-off-by: Simon Horman --- net/netfilter/ipvs/ip_vs_ctl.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 5aeb0dde6ccc..4d753beaac32 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -3078,6 +3078,17 @@ nla_put_failure: return skb->len; } +static bool ip_vs_is_af_valid(int af) +{ + if (af == AF_INET) + return true; +#ifdef CONFIG_IP_VS_IPV6 + if (af == AF_INET6 && ipv6_mod_enabled()) + return true; +#endif + return false; +} + static int ip_vs_genl_parse_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *usvc, struct nlattr *nla, int full_entry, @@ -3104,11 +3115,7 @@ static int ip_vs_genl_parse_service(struct netns_ipvs *ipvs, memset(usvc, 0, sizeof(*usvc)); usvc->af = nla_get_u16(nla_af); -#ifdef CONFIG_IP_VS_IPV6 - if (usvc->af != AF_INET && usvc->af != AF_INET6) -#else - if (usvc->af != AF_INET) -#endif + if (!ip_vs_is_af_valid(usvc->af)) return -EAFNOSUPPORT; if (nla_fwmark) { @@ -3610,6 +3617,11 @@ static int ip_vs_genl_set_cmd(struct sk_buff *skb, struct genl_info *info) if (udest.af == 0) udest.af = svc->af; + if (!ip_vs_is_af_valid(udest.af)) { + ret = -EAFNOSUPPORT; + goto out; + } + if (udest.af != svc->af && cmd != IPVS_CMD_DEL_DEST) { /* The synchronization protocol is incompatible * with mixed family services -- cgit v1.2.3