Merge ~whershberger/ubuntu/+source/glib2.0:ubuntu/noble-devel-lp2072586 into ubuntu/+source/glib2.0:ubuntu/noble-devel

[Wesley Hershberger]

gfileutils: Preserve mode during atomic file writes (LP: #2072586)

Backport 45a36e52

Unmerged commits

46e0c19... by Wesley Hershberger on 2025-04-25

gfileutils: Preserve mode during atomic file writes (LP: #2072586)

* gfileutils: Preserve mode during atomic file writes to prevent high umask
  from rendering dconf database files unreadable (LP: #2072586).
  - d/p/lp2072586-gfileutils-Preserve-mode-during-atomic-updates.patch

diff --git a/debian/changelog b/debian/changelog
index 4999ee8..e1645da 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+glib2.0 (2.80.0-6ubuntu3.3) jammy; urgency=medium
+
+  * gfileutils: Preserve mode during atomic file writes to prevent high umask
+    from rendering dconf database files unreadable (LP: #2072586).
+    - d/p/lp2072586-gfileutils-Preserve-mode-during-atomic-updates.patch
+
+ -- Wesley Hershberger <[e-mail]>  Fri, 25 Apr 2025 16:53:19 -0500
+
 glib2.0 (2.80.0-6ubuntu3.2) noble-security; urgency=medium
 
   * SECURITY UPDATE: Buffer overflow
diff --git a/debian/patches/lp2072586-gfileutils-Preserve-mode-during-atomic-updates.patch b/debian/patches/lp2072586-gfileutils-Preserve-mode-during-atomic-updates.patch
 new file mode 100644
index 0000000..bc83847
--- /dev/null
+++ b/debian/patches/lp2072586-gfileutils-Preserve-mode-during-atomic-updates.patch
@@ -0,0 +1,125 @@
+From: Wesley Hershberger <[e-mail]>
+Date: Tue, 22 Apr 2025 16:37:49 -0500
+Subject: gfileutils: Preserve mode during atomic updates
+
+If g_file_set_contents{_full,} is replacing an existing file, require
+that the tmpfile have the same mode as the existing file.
+
+This prevents the umask from taking effect for consistent writes to
+existing files.
+
+Closes GNOME/dconf#76
+
+Bug: https://gitlab.gnome.org/GNOME/dconf/-/issues/76
+Bug-Ubuntu: https://bugs.launchpad.net/bugs/2072586
+Origin: upstream, https://gitlab.gnome.org/GNOME/glib/-/commit/45a36e52b570cf86ce2599b657e63a83d284cb46
+---
+ glib/gfileutils.c      | 25 +++++++++++++++++++++++--
+ glib/tests/fileutils.c | 14 ++++++++++----
+ 2 files changed, 33 insertions(+), 6 deletions(-)
+
+diff --git a/glib/gfileutils.c b/glib/gfileutils.c
+index 2801777..7811016 100644
+--- a/glib/gfileutils.c
++++ b/glib/gfileutils.c
+@@ -1318,8 +1318,8 @@ g_file_set_contents (const gchar  *filename,
+  * to 7 characters to @filename.
+  *
+  * If the file didn’t exist before and is created, it will be given the
+- * permissions from @mode. Otherwise, the permissions of the existing file may
+- * be changed to @mode depending on @flags, or they may remain unchanged.
++ * permissions from @mode. Otherwise, the permissions of the existing file will
++ * remain unchanged.
+  *
+  * Returns: %TRUE on success, %FALSE if an error occurred
+  *
+@@ -1362,6 +1362,7 @@ g_file_set_contents_full (const gchar            *filename,
+       gboolean retval;
+       int fd;
+       gboolean do_fsync;
++      GStatBuf old_stat;
+ 
+       tmp_filename = g_strdup_printf ("%s.XXXXXX", filename);
+ 
+@@ -1379,6 +1380,26 @@ g_file_set_contents_full (const gchar            *filename,
+           goto consistent_out;
+         }
+ 
++      /* Maintain the permissions of the file if it exists */
++      if (!g_stat (filename, &old_stat))
++        {
++#ifndef G_OS_WIN32
++          if (fchmod (fd, old_stat.st_mode))
++#else  /* G_OS_WIN32 */
++          if (chmod (tmp_filename, old_stat.st_mode))
++#endif /* G_OS_WIN32 */
++            {
++              int saved_errno = errno;
++              if (error)
++                set_file_error (error,
++                                tmp_filename, _ ("Failed to set permissions of “%s”: %s"),
++                                saved_errno);
++              g_unlink (tmp_filename);
++              retval = FALSE;
++              goto consistent_out;
++            }
++        }
++
+       do_fsync = fd_should_be_fsynced (fd, filename, flags);
+       if (!write_to_file (contents, length, g_steal_fd (&fd), tmp_filename, do_fsync, error))
+         {
+diff --git a/glib/tests/fileutils.c b/glib/tests/fileutils.c
+index 56be804..b7b77e1 100644
+--- a/glib/tests/fileutils.c
++++ b/glib/tests/fileutils.c
+@@ -1686,7 +1686,9 @@ test_set_contents_full (void)
+           EXISTING_FILE_DIRECTORY,
+         }
+       existing_file;
+-      int new_mode;  /* only relevant if @existing_file is %EXISTING_FILE_NONE */
++      /* only relevant if @existing_file is
++       * %EXISTING_FILE_NONE or %EXISTING_FILE_REGULAR */
++      int mode;
+       gboolean use_strlen;
+ 
+       gboolean expected_success;
+@@ -1697,6 +1699,8 @@ test_set_contents_full (void)
+       { EXISTING_FILE_NONE, 0644, FALSE, TRUE, 0 },
+       { EXISTING_FILE_NONE, 0644, TRUE, TRUE, 0 },
+       { EXISTING_FILE_NONE, 0600, FALSE, TRUE, 0 },
++      // Assume umask is 022, ensures that we preserve perms with, eg. 077
++      { EXISTING_FILE_REGULAR, 0666, FALSE, TRUE, 0 },
+       { EXISTING_FILE_REGULAR, 0644, FALSE, TRUE, 0 },
+ #ifndef G_OS_WIN32
+       { EXISTING_FILE_SYMLINK, 0644, FALSE, TRUE, 0 },
+@@ -1741,6 +1745,8 @@ test_set_contents_full (void)
+                 g_assert_no_errno (g_fsync (fd));
+                 close (fd);
+ 
++                g_assert_no_errno (chmod (file_name, tests[i].mode));
++
+ #ifndef G_OS_WIN32
+                 /* Pass an existing symlink to g_file_set_contents_full() to see
+                  * what it does. */
+@@ -1784,7 +1790,7 @@ test_set_contents_full (void)
+           /* Set the file contents */
+           ret = g_file_set_contents_full (set_contents_name, "b",
+                                           tests[i].use_strlen ? -1 : 1,
+-                                          flags, tests[i].new_mode, &error);
++                                          flags, tests[i].mode, &error);
+ 
+           if (!tests[i].expected_success)
+             {
+@@ -1808,10 +1814,10 @@ test_set_contents_full (void)
+ 
+               g_assert_no_errno (g_lstat (set_contents_name, &statbuf));
+ 
+-              if (tests[i].existing_file == EXISTING_FILE_NONE)
++              if (tests[i].existing_file & (EXISTING_FILE_NONE | EXISTING_FILE_REGULAR))
+                 {
+                   int mode = statbuf.st_mode & ~S_IFMT;
+-                  int new_mode = tests[i].new_mode;
++                  int new_mode = tests[i].mode;
+ #ifdef G_OS_WIN32
+                   /* on windows, group and others perms handling is different */
+                   /* only check the rwx user permissions */
diff --git a/debian/patches/series b/debian/patches/series
index 2deb54b..5d89fd6 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -38,3 +38,4 @@ CVE-2024-34397-15.patch
 CVE-2024-34397-16.patch
 CVE-2024-34397-regression.patch
 CVE-2024-52533.patch
+lp2072586-gfileutils-Preserve-mode-during-atomic-updates.patch