xfrm: fix policy lookup for ipv6 gre packets

On egress side, xfrm lookup is called from __gre6_xmit() with the
fl6_gre_key field not initialized leading to policies selectors check
failure. Consequently, gre packets are sent without encryption.

On ingress side, INET6_PROTO_NOPOLICY was set, thus packets were not
checked against xfrm policies. Like for egress side, fl6_gre_key should be
correctly set, this is now done in decode_session6().

Fixes: c12b395a46 ("gre: Support GRE over IPv6")
Cc: stable@vger.kernel.org
Signed-off-by: Ghalem Boudour <ghalem.boudour@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Ghalem Boudour 2021-11-19 18:20:16 +01:00 committed by Steffen Klassert
parent 03a000bfd7
commit bcf141b2eb
2 changed files with 25 additions and 1 deletions

View File

@ -755,6 +755,7 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
fl6->daddr = key->u.ipv6.dst;
fl6->flowlabel = key->label;
fl6->flowi6_uid = sock_net_uid(dev_net(dev), NULL);
fl6->fl6_gre_key = tunnel_id_to_key32(key->tun_id);
dsfield = key->tos;
flags = key->tun_flags &
@ -990,6 +991,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
fl6.daddr = key->u.ipv6.dst;
fl6.flowlabel = key->label;
fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
fl6.fl6_gre_key = tunnel_id_to_key32(key->tun_id);
dsfield = key->tos;
if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
@ -1098,6 +1100,7 @@ static void ip6gre_tnl_link_config_common(struct ip6_tnl *t)
fl6->flowi6_oif = p->link;
fl6->flowlabel = 0;
fl6->flowi6_proto = IPPROTO_GRE;
fl6->fl6_gre_key = t->parms.o_key;
if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
@ -1544,7 +1547,7 @@ static void ip6gre_fb_tunnel_init(struct net_device *dev)
static struct inet6_protocol ip6gre_protocol __read_mostly = {
.handler = gre_rcv,
.err_handler = ip6gre_err,
.flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
.flags = INET6_PROTO_FINAL,
};
static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head)

View File

@ -33,6 +33,7 @@
#include <net/flow.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/gre.h>
#if IS_ENABLED(CONFIG_IPV6_MIP6)
#include <net/mip6.h>
#endif
@ -3422,6 +3423,26 @@ decode_session6(struct sk_buff *skb, struct flowi *fl, bool reverse)
}
fl6->flowi6_proto = nexthdr;
return;
case IPPROTO_GRE:
if (!onlyproto &&
(nh + offset + 12 < skb->data ||
pskb_may_pull(skb, nh + offset + 12 - skb->data))) {
struct gre_base_hdr *gre_hdr;
__be32 *gre_key;
nh = skb_network_header(skb);
gre_hdr = (struct gre_base_hdr *)(nh + offset);
gre_key = (__be32 *)(gre_hdr + 1);
if (gre_hdr->flags & GRE_KEY) {
if (gre_hdr->flags & GRE_CSUM)
gre_key++;
fl6->fl6_gre_key = *gre_key;
}
}
fl6->flowi6_proto = nexthdr;
return;
#if IS_ENABLED(CONFIG_IPV6_MIP6)
case IPPROTO_MH:
offset += ipv6_optlen(exthdr);