From 5c7263a5e59633ce46697b20d1faddc1c2d6121e Mon Sep 17 00:00:00 2001
From: Sukchan Lee <acetcom@gmail.com>
Date: Sun, 14 May 2023 10:34:36 +0900
Subject: [PATCH] [AMF/MME] Fixed crashes by M-TMSI (#2307)

---
 src/amf/context.c     | 3 +++
 src/mme/mme-context.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/src/amf/context.c b/src/amf/context.c
index c1075554c..dd80ecb8e 100644
--- a/src/amf/context.c
+++ b/src/amf/context.c
@@ -2437,6 +2437,9 @@ amf_m_tmsi_t *amf_m_tmsi_alloc(void)
 int amf_m_tmsi_free(amf_m_tmsi_t *m_tmsi)
 {
     ogs_assert(m_tmsi);
+
+    /* Restore M-TMSI by Issue #2307 */
+    *m_tmsi &= 0x003fffff;
     ogs_pool_free(&m_tmsi_pool, m_tmsi);
 
     return OGS_OK;
diff --git a/src/mme/mme-context.c b/src/mme/mme-context.c
index 3257d766b..9986ac401 100644
--- a/src/mme/mme-context.c
+++ b/src/mme/mme-context.c
@@ -3956,6 +3956,9 @@ mme_m_tmsi_t *mme_m_tmsi_alloc(void)
 int mme_m_tmsi_free(mme_m_tmsi_t *m_tmsi)
 {
     ogs_assert(m_tmsi);
+
+    /* Restore M-TMSI by Issue #2307 */
+    *m_tmsi &= 0x003fffff;
     ogs_pool_free(&m_tmsi_pool, m_tmsi);
 
     return OGS_OK;