xfrm: Check if_id in xfrm_migrate
[ Upstream commit c1aca3080e382886e2e58e809787441984a2f89b ]
This patch enables distinguishing SAs and SPs based on if_id during
the xfrm_migrate flow. This ensures support for xfrm interfaces
throughout the SA/SP lifecycle.
When there are multiple existing SPs with the same direction,
the same xfrm_selector and different endpoint addresses,
xfrm_migrate might fail with ENODATA.
Specifically, the code path for performing xfrm_migrate is:
Stage 1: find policy to migrate with
xfrm_migrate_policy_find(sel, dir, type, net)
Stage 2: find and update state(s) with
xfrm_migrate_state_find(mp, net)
Stage 3: update endpoint address(es) of template(s) with
xfrm_policy_migrate(pol, m, num_migrate)
Currently "Stage 1" always returns the first xfrm_policy that
matches, and "Stage 3" looks for the xfrm_tmpl that matches the
old endpoint address. Thus if there are multiple xfrm_policy
with same selector, direction, type and net, "Stage 1" might
rertun a wrong xfrm_policy and "Stage 3" will fail with ENODATA
because it cannot find a xfrm_tmpl with the matching endpoint
address.
The fix is to allow userspace to pass an if_id and add if_id
to the matching rule in Stage 1 and Stage 2 since if_id is a
unique ID for xfrm_policy and xfrm_state. For compatibility,
if_id will only be checked if the attribute is set.
Tested with additions to Android's kernel unit test suite:
https://android-review.googlesource.com/c/kernel/tests/+/1668886
Signed-off-by: Yan Yan <evitayan@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index f5b846a..37fe22b 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1569,7 +1569,8 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig,
return NULL;
}
-struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *net)
+struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *net,
+ u32 if_id)
{
unsigned int h;
struct xfrm_state *x = NULL;
@@ -1585,6 +1586,8 @@ struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *n
continue;
if (m->reqid && x->props.reqid != m->reqid)
continue;
+ if (if_id != 0 && x->if_id != if_id)
+ continue;
if (!xfrm_addr_equal(&x->id.daddr, &m->old_daddr,
m->old_family) ||
!xfrm_addr_equal(&x->props.saddr, &m->old_saddr,
@@ -1600,6 +1603,8 @@ struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *n
if (x->props.mode != m->mode ||
x->id.proto != m->proto)
continue;
+ if (if_id != 0 && x->if_id != if_id)
+ continue;
if (!xfrm_addr_equal(&x->id.daddr, &m->old_daddr,
m->old_family) ||
!xfrm_addr_equal(&x->props.saddr, &m->old_saddr,