commit 8133c780a22480496c74a4ead321e8350d5beeb4
author Benoît Ganne <bganne@cisco.com> Mon Sep 09 16:34:54 2019 +0200
committer Neale Ranns <nranns@cisco.com> Mon Sep 30 17:08:22 2019 +0000
tree e64ff73fe1eff5af98c7805b528882e208cf6264
parent 5c828bc1f24fb5222d6bb634d8e5228ed8b138f0

ipsec: fix use-after-free

When deleting interface from the API, 'hi' gets removed before
'h->sw_if_index' is copied.

Type: fix

Change-Id: I8e10108e9bdf95ab2fe002790d98262d583ca58c
Signed-off-by: Benoît Ganne <bganne@cisco.com>

src/vnet/ipsec/ipsec_if.c

diff --git a/src/vnet/ipsec/ipsec_if.c b/src/vnet/ipsec/ipsec_if.c
index f7f8ec7..a737274 100644
--- a/src/vnet/ipsec/ipsec_if.c
+++ b/src/vnet/ipsec/ipsec_if.c
@@ -268,12 +268,13 @@
 int
 ipsec_add_del_tunnel_if_internal (vnet_main_t * vnm,
 				  ipsec_add_del_tunnel_args_t * args,
-				  u32 * sw_if_index)
+				  u32 * sw_if_index_p)
 {
   ipsec_tunnel_if_t *t;
   ipsec_main_t *im = &ipsec_main;
   vnet_hw_interface_t *hi = NULL;
   u32 hw_if_index = ~0;
+  u32 sw_if_index = ~0;
   uword *p;
   u32 dev_instance;
   ipsec_key_t crypto_key, integ_key;
@@ -385,6 +386,7 @@
 					     t - im->tunnel_interfaces);
 
       hi = vnet_get_hw_interface (vnm, hw_if_index);
+      sw_if_index = hi->sw_if_index;
 
       t->hw_if_index = hw_if_index;
       t->sw_if_index = hi->sw_if_index;
@@ -420,6 +422,8 @@
       ti = p[0];
       t = pool_elt_at_index (im->tunnel_interfaces, ti);
       hi = vnet_get_hw_interface (vnm, t->hw_if_index);
+      sw_if_index = hi->sw_if_index;
+
       vnet_sw_interface_set_flags (vnm, hi->sw_if_index, 0);	/* admin down */
 
       ipsec_tunnel_feature_set (im, t, 0);
@@ -440,8 +444,8 @@
       pool_put (im->tunnel_interfaces, t);
     }
 
-  if (sw_if_index)
-    *sw_if_index = hi->sw_if_index;
+  if (sw_if_index_p)
+    *sw_if_index_p = sw_if_index;
 
   return 0;
 }