Revert "xfrm: state and policy should fail if XFRMA_IF_ID 0"

commit a3d9001b4e287fc043e5539d03d71a32ab114bcb upstream.

This reverts commit 68ac0f3810e76a853b5f7b90601a05c3048b8b54 because ID
0 was meant to be used for configuring the policy/state without
matching for a specific interface (e.g., Cilium is affected, see
https://github.com/cilium/cilium/pull/18789 and
https://github.com/cilium/cilium/pull/19019).

Signed-off-by: Kai Lueke <kailueke@linux.microsoft.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index b10f88822c0df005f3b64205ce66ae8b0e46b5e3..e13198f7e4e94e583ed3e0e7d33d4421bfc5ba7a 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -629,13 +629,8 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
 
        xfrm_smark_init(attrs, &x->props.smark);
 
-       if (attrs[XFRMA_IF_ID]) {
+       if (attrs[XFRMA_IF_ID])
                x->if_id = nla_get_u32(attrs[XFRMA_IF_ID]);
-               if (!x->if_id) {
-                       err = -EINVAL;
-                       goto error;
-               }
-       }
 
        err = __xfrm_init_state(x, false, attrs[XFRMA_OFFLOAD_DEV]);
        if (err)
@@ -1431,13 +1426,8 @@ static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh,
 
        mark = xfrm_mark_get(attrs, &m);
 
-       if (attrs[XFRMA_IF_ID]) {
+       if (attrs[XFRMA_IF_ID])
                if_id = nla_get_u32(attrs[XFRMA_IF_ID]);
-               if (!if_id) {
-                       err = -EINVAL;
-                       goto out_noput;
-               }
-       }
 
        if (p->info.seq) {
                x = xfrm_find_acq_byseq(net, mark, p->info.seq);
@@ -1750,13 +1740,8 @@ static struct xfrm_policy *xfrm_policy_construct(struct net *net, struct xfrm_us
 
        xfrm_mark_get(attrs, &xp->mark);
 
-       if (attrs[XFRMA_IF_ID]) {
+       if (attrs[XFRMA_IF_ID])
                xp->if_id = nla_get_u32(attrs[XFRMA_IF_ID]);
-               if (!xp->if_id) {
-                       err = -EINVAL;
-                       goto error;
-               }
-       }
 
        return xp;
  error: