From: Matthias Schiffer Date: Mon, 2 Nov 2015 00:24:38 +0000 (+0100) Subject: ipv6: fix crash on ICMPv6 redirects with prohibited/blackholed source X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ec13ad1d705c9990d55ed8ab21946cef323d30c7;p=linux-beck.git ipv6: fix crash on ICMPv6 redirects with prohibited/blackholed source There are other error values besides ip6_null_entry that can be returned by ip6_route_redirect(): fib6_rule_action() can also result in ip6_blk_hole_entry and ip6_prohibit_entry if such ip rules are installed. Only checking for ip6_null_entry in rt6_do_redirect() causes ip6_ins_rt() to be called with rt->rt6i_table == NULL in these cases, making the kernel crash. Signed-off-by: Matthias Schiffer Signed-off-by: David S. Miller --- diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 946880ad48ac..cc88a73b9ce0 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2099,7 +2099,6 @@ static int ip6_route_del(struct fib6_config *cfg) static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) { - struct net *net = dev_net(skb->dev); struct netevent_redirect netevent; struct rt6_info *rt, *nrt = NULL; struct ndisc_options ndopts; @@ -2160,7 +2159,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu } rt = (struct rt6_info *) dst; - if (rt == net->ipv6.ip6_null_entry) { + if (rt->rt6i_flags & RTF_REJECT) { net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n"); return; }