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Commit 3c21ece7 authored by Yan Yan's avatar Yan Yan Committed by Greg Kroah-Hartman
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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: default avatarYan Yan <evitayan@google.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 970a2140

include/net/xfrm.h

+3 −2
Original line number Diff line number Diff line
@@ -1663,14 +1663,15 @@ int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, 
	       const struct xfrm_migrate *m, int num_bundles,

	       const struct xfrm_kmaddress *k,

	       const struct xfrm_encap_tmpl *encap);

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);

struct xfrm_state *xfrm_state_migrate(struct xfrm_state *x,

				      struct xfrm_migrate *m,

				      struct xfrm_encap_tmpl *encap);

int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,

		 struct xfrm_migrate *m, int num_bundles,

		 struct xfrm_kmaddress *k, struct net *net,

		 struct xfrm_encap_tmpl *encap);

		 struct xfrm_encap_tmpl *encap, u32 if_id);

#endif



int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);

net/key/af_key.c

+1 −1
Original line number Diff line number Diff line
@@ -2627,7 +2627,7 @@ static int pfkey_migrate(struct sock *sk, struct sk_buff *skb, 
	}



	return xfrm_migrate(&sel, dir, XFRM_POLICY_TYPE_MAIN, m, i,

			    kma ? &k : NULL, net, NULL);

			    kma ? &k : NULL, net, NULL, 0);



 out:

	return err;

net/xfrm/xfrm_policy.c

+8 −6
Original line number Diff line number Diff line
@@ -4271,7 +4271,7 @@ static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp, 
}



static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel,

						    u8 dir, u8 type, struct net *net)

						    u8 dir, u8 type, struct net *net, u32 if_id)

{

	struct xfrm_policy *pol, *ret = NULL;

	struct hlist_head *chain;
@@ -4280,7 +4280,8 @@ static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector * 
	spin_lock_bh(&net->xfrm.xfrm_policy_lock);

	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);

	hlist_for_each_entry(pol, chain, bydst) {

		if (xfrm_migrate_selector_match(sel, &pol->selector) &&

		if ((if_id == 0 || pol->if_id == if_id) &&

		    xfrm_migrate_selector_match(sel, &pol->selector) &&

		    pol->type == type) {

			ret = pol;

			priority = ret->priority;
@@ -4292,7 +4293,8 @@ static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector * 
		if ((pol->priority >= priority) && ret)

			break;



		if (xfrm_migrate_selector_match(sel, &pol->selector) &&

		if ((if_id == 0 || pol->if_id == if_id) &&

		    xfrm_migrate_selector_match(sel, &pol->selector) &&

		    pol->type == type) {

			ret = pol;

			break;
@@ -4408,7 +4410,7 @@ static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate) 
int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,

		 struct xfrm_migrate *m, int num_migrate,

		 struct xfrm_kmaddress *k, struct net *net,

		 struct xfrm_encap_tmpl *encap)

		 struct xfrm_encap_tmpl *encap, u32 if_id)

{

	int i, err, nx_cur = 0, nx_new = 0;

	struct xfrm_policy *pol = NULL;
@@ -4427,14 +4429,14 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, 
	}



	/* Stage 1 - find policy */

	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {

	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id)) == NULL) {

		err = -ENOENT;

		goto out;

	}



	/* Stage 2 - find and update state(s) */

	for (i = 0, mp = m; i < num_migrate; i++, mp++) {

		if ((x = xfrm_migrate_state_find(mp, net))) {

		if ((x = xfrm_migrate_state_find(mp, net, if_id))) {

			x_cur[nx_cur] = x;

			nx_cur++;

			xc = xfrm_state_migrate(x, mp, encap);

net/xfrm/xfrm_state.c

+6 −1
Original line number Diff line number Diff line
@@ -1563,7 +1563,8 @@ 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;
@@ -1579,6 +1580,8 @@ 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,
@@ -1594,6 +1597,8 @@ 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,

net/xfrm/xfrm_user.c

+5 −1
Original line number Diff line number Diff line
@@ -2374,6 +2374,7 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh, 
	int n = 0;

	struct net *net = sock_net(skb->sk);

	struct xfrm_encap_tmpl  *encap = NULL;

	u32 if_id = 0;



	if (attrs[XFRMA_MIGRATE] == NULL)

		return -EINVAL;
@@ -2398,7 +2399,10 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh, 
			return 0;

	}



	err = xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp, net, encap);

	if (attrs[XFRMA_IF_ID])

		if_id = nla_get_u32(attrs[XFRMA_IF_ID]);



	err = xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp, net, encap, if_id);



	kfree(encap);