From 0a1f59620068fb82a2e2aded202e62f4bb856d52 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Thu, 15 Oct 2015 16:39:58 -0700 Subject: [PATCH] ipv6: Initialize rt6_info properly in ip6_blackhole_route() ip6_blackhole_route() does not initialize the newly allocated rt6_info properly. This patch: 1. Call rt6_info_init() to initialize rt6i_siblings and rt6i_uncached 2. The current rt->dst._metrics init code is incorrect: - 'rt->dst._metrics = ort->dst._metris' is not always safe - Not sure what dst_copy_metrics() is trying to do here considering ip6_rt_blackhole_cow_metrics() always returns NULL Fix: - Always do dst_copy_metrics() - Replace ip6_rt_blackhole_cow_metrics() with dst_cow_metrics_generic() 3. Mask out the RTF_PCPU bit from the newly allocated blackhole route. This bug triggers an oops (reported by Phil Sutter) in rt6_get_cookie(). It is because RTF_PCPU is set while rt->dst.from is NULL. Fixes: d52d3997f843 ("ipv6: Create percpu rt6_info") Signed-off-by: Martin KaFai Lau Reported-by: Phil Sutter Tested-by: Phil Sutter Cc: Hannes Frederic Sowa Cc: Julian Anastasov Cc: Phil Sutter Cc: Steffen Klassert Signed-off-by: David S. Miller --- net/ipv6/route.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 4198017a5aa7..968f31c01f89 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -248,12 +248,6 @@ static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, { } -static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst, - unsigned long old) -{ - return NULL; -} - static struct dst_ops ip6_dst_blackhole_ops = { .family = AF_INET6, .destroy = ip6_dst_destroy, @@ -262,7 +256,7 @@ static struct dst_ops ip6_dst_blackhole_ops = { .default_advmss = ip6_default_advmss, .update_pmtu = ip6_rt_blackhole_update_pmtu, .redirect = ip6_rt_blackhole_redirect, - .cow_metrics = ip6_rt_blackhole_cow_metrics, + .cow_metrics = dst_cow_metrics_generic, .neigh_lookup = ip6_neigh_lookup, }; @@ -1219,24 +1213,20 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0); if (rt) { - new = &rt->dst; - - memset(new + 1, 0, sizeof(*rt) - sizeof(*new)); + rt6_info_init(rt); + new = &rt->dst; new->__use = 1; new->input = dst_discard; new->output = dst_discard_sk; - if (dst_metrics_read_only(&ort->dst)) - new->_metrics = ort->dst._metrics; - else - dst_copy_metrics(new, &ort->dst); + dst_copy_metrics(new, &ort->dst); rt->rt6i_idev = ort->rt6i_idev; if (rt->rt6i_idev) in6_dev_hold(rt->rt6i_idev); rt->rt6i_gateway = ort->rt6i_gateway; - rt->rt6i_flags = ort->rt6i_flags; + rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU; rt->rt6i_metric = 0; memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); -- 2.30.2