From d4aeb84c3f066b755b723163da292eab95bd1ef9 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Beno=C3=AEt=20Ganne?= <bganne@cisco.com>
Date: Thu, 18 Jul 2019 18:38:42 +0200
Subject: [PATCH] session: fix use-after-free
MIME-Version: 1.0
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Make sure to reinitialize data before free-ing it.

Type: fix

Change-Id: I45727c456d0345204d4825ecdd9690c5ebeb5e94
Signed-off-by: Benoît Ganne <bganne@cisco.com>
---
 src/plugins/sctp/sctp.h               | 4 ++--
 src/vnet/session/application.c        | 2 +-
 src/vnet/session/application_worker.c | 2 +-
 src/vnet/tcp/tcp.c                    | 2 +-
 src/vnet/udp/udp.c                    | 3 ++-
 5 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/plugins/sctp/sctp.h b/src/plugins/sctp/sctp.h
index a99b01c1c0a..aa2409ecce8 100644
--- a/src/plugins/sctp/sctp.h
+++ b/src/plugins/sctp/sctp.h
@@ -607,11 +607,11 @@ always_inline void
 sctp_half_open_connection_del (sctp_connection_t * tc)
 {
   sctp_main_t *sctp_main = vnet_get_sctp_main ();
+  u32 index = tc->sub_conn[SCTP_PRIMARY_PATH_IDX].c_c_index;
   clib_spinlock_lock_if_init (&sctp_main->half_open_lock);
-  pool_put_index (sctp_main->half_open_connections,
-		  tc->sub_conn[SCTP_PRIMARY_PATH_IDX].c_c_index);
   if (CLIB_DEBUG)
     clib_memset (tc, 0xFA, sizeof (*tc));
+  pool_put_index (sctp_main->half_open_connections, index);
   clib_spinlock_unlock_if_init (&sctp_main->half_open_lock);
 }
 
diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index d4f3d61ab61..583c4b055ee 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -52,9 +52,9 @@ static void
 app_listener_free (application_t * app, app_listener_t * app_listener)
 {
   clib_bitmap_free (app_listener->workers);
-  pool_put (app->listeners, app_listener);
   if (CLIB_DEBUG)
     clib_memset (app_listener, 0xfa, sizeof (*app_listener));
+  pool_put (app->listeners, app_listener);
 }
 
 session_handle_t
diff --git a/src/vnet/session/application_worker.c b/src/vnet/session/application_worker.c
index 30edf3c32cc..c45679735b9 100644
--- a/src/vnet/session/application_worker.c
+++ b/src/vnet/session/application_worker.c
@@ -109,9 +109,9 @@ app_worker_free (app_worker_t * app_wrk)
 	segment_manager_free (sm);
     }
 
-  pool_put (app_workers, app_wrk);
   if (CLIB_DEBUG)
     clib_memset (app_wrk, 0xfe, sizeof (*app_wrk));
+  pool_put (app_workers, app_wrk);
 }
 
 application_t *
diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c
index 75a45a448bd..8467ea4fd67 100644
--- a/src/vnet/tcp/tcp.c
+++ b/src/vnet/tcp/tcp.c
@@ -192,9 +192,9 @@ tcp_half_open_connection_del (tcp_connection_t * tc)
 {
   tcp_main_t *tm = vnet_get_tcp_main ();
   clib_spinlock_lock_if_init (&tm->half_open_lock);
-  pool_put_index (tm->half_open_connections, tc->c_c_index);
   if (CLIB_DEBUG)
     clib_memset (tc, 0xFA, sizeof (*tc));
+  pool_put (tm->half_open_connections, tc);
   clib_spinlock_unlock_if_init (&tm->half_open_lock);
 }
 
diff --git a/src/vnet/udp/udp.c b/src/vnet/udp/udp.c
index 949c6356d33..fbd9e980181 100644
--- a/src/vnet/udp/udp.c
+++ b/src/vnet/udp/udp.c
@@ -58,9 +58,10 @@ udp_connection_alloc (u32 thread_index)
 void
 udp_connection_free (udp_connection_t * uc)
 {
-  pool_put (udp_main.connections[uc->c_thread_index], uc);
+  u32 thread_index = uc->c_thread_index;
   if (CLIB_DEBUG)
     clib_memset (uc, 0xFA, sizeof (*uc));
+  pool_put (udp_main.connections[thread_index], uc);
 }
 
 void
-- 
2.16.6