From 25a1fab5b6c5ef2a8bb109232b765cb8b332ce5e Mon Sep 17 00:00:00 2001
From: matt335672 <30179339+matt335672@users.noreply.github.com>
Date: Sat, 19 Aug 2023 13:35:26 +0100
Subject: [PATCH] Check auth_start_session() result

---
 sesman/libsesman/verify_user_pam.c          | 24 +++++++++++++++++++--
 sesman/libsesman/verify_user_pam_userpass.c | 24 +++++++++++++++++++--
 sesman/sesexec/session.c                    |  7 +++++-
 3 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/sesman/libsesman/verify_user_pam.c b/sesman/libsesman/verify_user_pam.c
index b400bb5e2c..ca5136688d 100644
--- a/sesman/libsesman/verify_user_pam.c
+++ b/sesman/libsesman/verify_user_pam.c
@@ -397,8 +397,8 @@ auth_uds(const char *user, enum scp_login_status *errorcode)
 /******************************************************************************/
 
 /* returns error */
-int
-auth_start_session(struct auth_info *auth_info, int display_num)
+static int
+auth_start_session_private(struct auth_info *auth_info, int display_num)
 {
     int error;
     char display[256];
@@ -436,6 +436,26 @@ auth_start_session(struct auth_info *auth_info, int display_num)
     return 0;
 }
 
+/******************************************************************************/
+/**
+ * Main routine to start a session
+ *
+ * Calls the private routine and logs an additional error if the private
+ * routine fails
+ */
+int
+auth_start_session(struct auth_info *auth_info, int display_num)
+{
+    int result = auth_start_session_private(auth_info, display_num);
+    if (result != 0)
+    {
+        LOG(LOG_LEVEL_ERROR,
+            "Can't start PAM session. See PAM logging for more info");
+    }
+
+    return result;
+}
+
 /******************************************************************************/
 /* returns error */
 static int
diff --git a/sesman/libsesman/verify_user_pam_userpass.c b/sesman/libsesman/verify_user_pam_userpass.c
index 349d811145..9a6f657c2c 100644
--- a/sesman/libsesman/verify_user_pam_userpass.c
+++ b/sesman/libsesman/verify_user_pam_userpass.c
@@ -207,8 +207,8 @@ auth_uds(const char *user, enum scp_login_status *errorcode)
 /******************************************************************************/
 
 /* returns error */
-int
-auth_start_session(struct auth_info *auth_info, int display_num)
+static int
+auth_start_session_private(struct auth_info *auth_info, int display_num)
 {
     int error;
     char display[256];
@@ -246,6 +246,26 @@ auth_start_session(struct auth_info *auth_info, int display_num)
     return 0;
 }
 
+/******************************************************************************/
+/**
+ * Main routine to start a session
+ *
+ * Calls the private routine and logs an additional error if the private
+ * routine fails
+ */
+int
+auth_start_session(struct auth_info *auth_info, int display_num)
+{
+    int result = auth_start_session_private(auth_info, display_num);
+    if (result != 0)
+    {
+        LOG(LOG_LEVEL_ERROR,
+            "Can't start PAM session. See PAM logging for more info");
+    }
+
+    return result;
+}
+
 /******************************************************************************/
 /* returns error */
 static int
diff --git a/sesman/sesexec/session.c b/sesman/sesexec/session.c
index 6836d5c47d..900b394333 100644
--- a/sesman/sesexec/session.c
+++ b/sesman/sesexec/session.c
@@ -568,7 +568,12 @@ session_start_wrapped(struct login_info *login_info,
     int window_manager_pid;
     enum scp_screate_status status = E_SCP_SCREATE_GENERAL_ERROR;
 
-    auth_start_session(login_info->auth_info, s->display);
+    if (auth_start_session(login_info->auth_info, s->display) != 0)
+    {
+        // Errors are logged by the auth module, as they are
+        // specific to that module
+        return E_SCP_SCREATE_GENERAL_ERROR;
+    }
 #ifdef USE_BSD_SETLOGIN
     /**
      * Create a new session and process group since the 4.4BSD