From: Matthias Schiffer Date: Mon, 2 Nov 2015 02:02:02 +0100 Subject: 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. diff --git a/target/linux/generic/patches-3.18/672-ipv6-fix-crash-on-ICMPv6-redirects-with-prohibited-blackholed-source.patch b/target/linux/generic/patches-3.18/672-ipv6-fix-crash-on-ICMPv6-redirects-with-prohibited-blackholed-source.patch new file mode 100644 index 0000000000000000000000000000000000000000..6e4b3da3ad820e789f57df71b33ccfc5eaead01e --- /dev/null +++ b/target/linux/generic/patches-3.18/672-ipv6-fix-crash-on-ICMPv6-redirects-with-prohibited-blackholed-source.patch @@ -0,0 +1,39 @@ +From 7426eb388ade0f1ad800c408d7efa227d4f41408 Mon Sep 17 00:00:00 2001 +Message-Id: <7426eb388ade0f1ad800c408d7efa227d4f41408.1446425986.git.mschiffer@universe-factory.net> +From: Matthias Schiffer +Date: Mon, 2 Nov 2015 01:05:15 +0100 +Subject: [PATCH] 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 +--- + net/ipv6/route.c | 3 +-- + 1 file changed, 1 insertion(+), 2 deletions(-) + +--- a/net/ipv6/route.c ++++ b/net/ipv6/route.c +@@ -1766,7 +1766,6 @@ static int ip6_route_del(struct fib6_con + + 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; +@@ -1827,7 +1826,7 @@ static void rt6_do_redirect(struct dst_e + } + + 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; + }