xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

xfrm: Check if_id in xfrm_migrate

Browse Source 
[ 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>
This commit is contained in:
Yan Yan
2022-01-18 16:00:13 -08:00
committed by Greg Kroah-Hartman
parent 6056abc99b
commit d8889a445b
5 changed files with 23 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
net/xfrm/xfrm_policy.c
View File

@@ -4287,7 +4287,7 @@ 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;
@@ -4296,7 +4296,8 @@ 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;
@@ -4308,7 +4309,8 @@ 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;
@@ -4424,7 +4426,7 @@ 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;
@@ -4443,14 +4445,14 @@ 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);