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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: d52d3997f8 ("ipv6: Create percpu rt6_info")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reported-by: Phil Sutter <phil@nwl.cc>
Tested-by: Phil Sutter <phil@nwl.cc>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Phil Sutter <phil@nwl.cc>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Martin KaFai Lau 2015-10-15 16:39:58 -07:00 committed by David S. Miller
parent ebfa45f0d9
commit 0a1f596200
1 changed files with 5 additions and 15 deletions
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20
net/ipv6/route.c
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@ -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) {
rt6_info_init(rt);
new = &rt->dst;
memset(new + 1, 0, sizeof(*rt) - sizeof(*new));
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));