File 0004-rdp-sam-Dup-fd-kept-in-struct.patch of Package gnome-remote-desktop

From 99d246dfae3562640c65cb08a369e172947c7210 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 28 May 2025 14:08:12 +0200
Subject: [PATCH 04/13] rdp-sam: Dup fd kept in struct

The SAM file instance intends to keeps the file descriptor alive so that
it doesn't go away; however it failed to do this due to fdopen() taking
ownership of it, thus closing it during fclose(). This meant we'd close
an arbitrary potentially reused file descriptor when the SAM file
instance eventually got cleaned up. Address this by reordering things a
bit, while putting a duplicated file descriptor in the SAM file instance
struct.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/merge_requests/321>
---
 src/grd-rdp-sam.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/src/grd-rdp-sam.c b/src/grd-rdp-sam.c
index 5898825..daa3ebb 100644
--- a/src/grd-rdp-sam.c
+++ b/src/grd-rdp-sam.c
@@ -72,11 +72,12 @@ grd_rdp_sam_create_sam_file (const char *username,
 {
   const char *grd_path = "/gnome-remote-desktop";
   const char *template = "/rdp-sam-XXXXXX";
+  int duped_fd;
   GrdRdpSAMFile *rdp_sam_file;
   g_autofree char *file_dir = NULL;
   g_autofree char *filename = NULL;
   g_autofree char *sam_string = NULL;
-  int fd;
+  g_autofd int fd = -1;
   FILE *sam_file;
 
   file_dir = g_strdup_printf ("%s%s", g_get_user_runtime_dir (), grd_path);
@@ -98,20 +99,29 @@ grd_rdp_sam_create_sam_file (const char *username,
       return NULL;
     }
 
-  rdp_sam_file = g_new0 (GrdRdpSAMFile, 1);
-  rdp_sam_file->fd = fd;
-  rdp_sam_file->filename = g_steal_pointer (&filename);
-
-  sam_string = create_sam_string (username, password);
-
-  sam_file = fdopen (rdp_sam_file->fd, "w+");
+  sam_file = fdopen (fd, "w+");
   if (!sam_file)
     {
       g_warning ("[RDP] Failed to open SAM database: %s", g_strerror (errno));
-      grd_rdp_sam_free_sam_file (rdp_sam_file);
       return NULL;
     }
 
+  duped_fd = dup (fd);
+  if (duped_fd < 0)
+    {
+      fclose (sam_file);
+      g_warning ("[RDP] Failed to dup fd: %s", g_strerror (errno));
+      return NULL;
+    }
+
+  rdp_sam_file = g_new0 (GrdRdpSAMFile, 1);
+  rdp_sam_file->fd = duped_fd;
+  rdp_sam_file->filename = g_steal_pointer (&filename);
+
+  g_steal_fd (&fd);
+
+  sam_string = create_sam_string (username, password);
+
   fputs (sam_string, sam_file);
   fclose (sam_file);
 
-- 
2.53.0