Commit c0a47e44 authored by Hangbin Liu's avatar Hangbin Liu Committed by David S. Miller

geneve: should not call rt6_lookup() when ipv6 was disabled

When we add a new GENEVE device with IPv6 remote, checking only for
IS_ENABLED(CONFIG_IPV6) is not enough as we may disable IPv6 in the
kernel command line (ipv6.disable=1), and calling rt6_lookup() would
cause a NULL pointer dereference.

v2:
- don't mix declarations and code (reported by Stefano Brivio, Eric Dumazet)
- there's no need to use in6_dev_get() as we only need to check that
  idev exists (reported by David Ahern). This is under RTNL, so we can
  simply use __in6_dev_get() instead (Stefano, Eric).
Reported-by: 's avatarJianlin Shi <jishi@redhat.com>
Fixes: c40e89fd ("geneve: configure MTU based on a lower device")
Cc: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Hangbin Liu's avatarHangbin Liu <liuhangbin@gmail.com>
Reviewed-by: 's avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
parent e8c32c32
...@@ -1512,9 +1512,13 @@ static void geneve_link_config(struct net_device *dev, ...@@ -1512,9 +1512,13 @@ static void geneve_link_config(struct net_device *dev,
} }
#if IS_ENABLED(CONFIG_IPV6) #if IS_ENABLED(CONFIG_IPV6)
case AF_INET6: { case AF_INET6: {
struct rt6_info *rt = rt6_lookup(geneve->net, struct rt6_info *rt;
&info->key.u.ipv6.dst, NULL, 0,
NULL, 0); if (!__in6_dev_get(dev))
break;
rt = rt6_lookup(geneve->net, &info->key.u.ipv6.dst, NULL, 0,
NULL, 0);
if (rt && rt->dst.dev) if (rt && rt->dst.dev)
ldev_mtu = rt->dst.dev->mtu - GENEVE_IPV6_HLEN; ldev_mtu = rt->dst.dev->mtu - GENEVE_IPV6_HLEN;
......
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