[PATCH 4.14 09/14] Revert "xfrm: Fix stack-out-of-bounds read in xfrm_state_find."

From: Greg Kroah-Hartman
Date: Thu Jan 04 2018 - 07:12:12 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>

commit 94802151894d482e82c324edf2c658f8e6b96508 upstream.

This reverts commit c9f3f813d462c72dbe412cee6a5cbacf13c4ad5e.

This commit breaks transport mode when the policy template
has widlcard addresses configured, so revert it.

Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Cc: From: Derek Robson <robsonde@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/xfrm/xfrm_policy.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)

--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1362,29 +1362,36 @@ xfrm_tmpl_resolve_one(struct xfrm_policy
struct net *net = xp_net(policy);
int nx;
int i, error;
+ xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family);
+ xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family);
xfrm_address_t tmp;

for (nx = 0, i = 0; i < policy->xfrm_nr; i++) {
struct xfrm_state *x;
- xfrm_address_t *local;
- xfrm_address_t *remote;
+ xfrm_address_t *remote = daddr;
+ xfrm_address_t *local = saddr;
struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];

- remote = &tmpl->id.daddr;
- local = &tmpl->saddr;
- if (xfrm_addr_any(local, tmpl->encap_family)) {
- error = xfrm_get_saddr(net, fl->flowi_oif,
- &tmp, remote,
- tmpl->encap_family, 0);
- if (error)
- goto fail;
- local = &tmp;
+ if (tmpl->mode == XFRM_MODE_TUNNEL ||
+ tmpl->mode == XFRM_MODE_BEET) {
+ remote = &tmpl->id.daddr;
+ local = &tmpl->saddr;
+ if (xfrm_addr_any(local, tmpl->encap_family)) {
+ error = xfrm_get_saddr(net, fl->flowi_oif,
+ &tmp, remote,
+ tmpl->encap_family, 0);
+ if (error)
+ goto fail;
+ local = &tmp;
+ }
}

x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family);

if (x && x->km.state == XFRM_STATE_VALID) {
xfrm[nx++] = x;
+ daddr = remote;
+ saddr = local;
continue;
}
if (x) {