route: Use the device mtu as the default for blackhole routes

As it is, we return null as the default mtu of blackhole routes. This may lead to a propagation of a bogus pmtu if the default_mtu method of a blackhole route is invoked. So return dst->dev->mtu as the default mtu instead. Signed-off-by: Steffen Klassert <[email protected]> Signed-off-by: David S. Miller <[email protected]>
syzer · Nov 26, 2011 · 6b600b2 · 6b600b2
1 parent df07a94
commit 6b600b2
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
@@ -2757,7 +2757,7 @@ static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 coo
 
 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
 {
-	return 0;
+	return dst->dev->mtu;
 }
 
 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
@@ -157,7 +157,7 @@ static struct dst_ops ip6_dst_ops_template = {
 
 static unsigned int ip6_blackhole_default_mtu(const struct dst_entry *dst)
 {
-	return 0;
+	return dst->dev->mtu;
 }
 
 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)