diff mbox series

[3/3] xfrm: Fix stack-out-of-bounds read in xfrm_state_find.

Message ID 1510191647-28122-4-git-send-email-steffen.klassert@secunet.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series pull request (net): ipsec 2017-11-09 | expand

Commit Message

Steffen Klassert Nov. 9, 2017, 1:40 a.m. UTC
When we do tunnel or beet mode, we pass saddr and daddr from the
template to xfrm_state_find(), this is ok. On transport mode,
we pass the addresses from the flowi, assuming that the IP
addresses (and address family) don't change during transformation.
This assumption is wrong in the IPv4 mapped IPv6 case, packet
is IPv4 and template is IPv6. Fix this by using the addresses
from the template unconditionally.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_policy.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index a2e531b..6eb228a 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1361,36 +1361,29 @@  xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
 	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 *remote = daddr;
-		xfrm_address_t *local  = saddr;
+		xfrm_address_t *local;
+		xfrm_address_t *remote;
 		struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i];
 
-		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;
-			}
+		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) {