From 168b5b666162d51badd0cf990237e17f792538ff Mon Sep 17 00:00:00 2001
From: RHEL Packaging Agent <redhat-ymir-agent@redhat.com>
Date: Fri, 24 Jul 2026 13:03:51 +0000
Subject: [PATCH] Fix CVE-2026-58016: XML parser state handling for node
 nesting

Backport fix for CVE-2026-58016 from upstream commit
c9da977c178fbfc0e4caf99f9fdf5dc433d6fcc2 (MR !5156).

The fix corrects broken XML parser state handling for
<node> element nesting in gio/gdbusintrospection.c, and
adds unit tests for invalid introspection XML parsing.

CVE: CVE-2026-58016
Upstream patches:
 - https://gitlab.gnome.org/GNOME/glib/-/commit/c9da977c178fbfc0e4caf99f9fdf5dc433d6fcc2.patch
Resolves: RHEL-190613

This commit was backported by Ymir, a Red Hat Enterprise Linux software maintenance AI agent.

Assisted-by: Ymir
---
 CVE-2026-58016.patch | 87 ++++++++++++++++++++++++++++++++++++++++++++
 glib2.spec           |  3 ++
 2 files changed, 90 insertions(+)
 create mode 100644 CVE-2026-58016.patch

diff --git a/CVE-2026-58016.patch b/CVE-2026-58016.patch
new file mode 100644
index 0000000..e5f1427
--- /dev/null
+++ b/CVE-2026-58016.patch
@@ -0,0 +1,87 @@
+From 60f855a3ec113381fd2d54c633ab2ca282dbd92c Mon Sep 17 00:00:00 2001
+From: Philip Withnall <pwithnall@gnome.org>
+Date: Thu, 16 Apr 2026 15:27:37 +0100
+Subject: [PATCH] gdbusintrospection: Fix XML parser state handling for <node>
+ element nesting
+
+The check for whether a `<node>` element in D-Bus introspection XML was
+nested correctly was broken. `<node>` elements can only be at the top
+level, or nested immediately within another `<node>` element.
+
+Fix the check and add some unit tests for it.
+
+Spotted by linhlhq as #YWH-PGM9867-204. The fix is mine, and the unit test
+uses example XML strings adapted from their report.
+
+Signed-off-by: Philip Withnall <pwithnall@gnome.org>
+
+Fixes: #3932
+---
+ gio/gdbusintrospection.c        |  2 +-
+ gio/tests/gdbus-introspection.c | 33 +++++++++++++++++++++++++++++++++
+ 2 files changed, 34 insertions(+), 1 deletion(-)
+
+diff --git a/gio/gdbusintrospection.c b/gio/gdbusintrospection.c
+index 7ee3e32b6..7a113dbda 100644
+--- a/gio/gdbusintrospection.c
++++ b/gio/gdbusintrospection.c
+@@ -1258,7 +1258,7 @@ parser_start_element (GMarkupParseContext  *context,
+   /* ---------------------------------------------------------------------------------------------------- */
+   if (strcmp (element_name, "node") == 0)
+     {
+-      if (!(g_slist_length (stack) >= 1 || strcmp (stack->next->data, "node") != 0))
++      if (stack->next != NULL && strcmp (stack->next->data, "node") != 0)
+         {
+           g_set_error_literal (error,
+                                G_MARKUP_ERROR,
+diff --git a/gio/tests/gdbus-introspection.c b/gio/tests/gdbus-introspection.c
+index 44cb7a96a..5c2c65c3b 100644
+--- a/gio/tests/gdbus-introspection.c
++++ b/gio/tests/gdbus-introspection.c
+@@ -299,6 +299,38 @@ test_extra_data (void)
+   g_dbus_node_info_unref (info);
+ }
+ 
++static void
++test_invalid (void)
++{
++  const struct
++    {
++      const char *xml;
++      GMarkupError expected_error_code;
++    }
++  vectors[] =
++    {
++      { "", G_MARKUP_ERROR_EMPTY },
++      { "<node><interface name=\"I\"><method name=\"M\"><node><interface name=\"I2\"></interface></node></method>", G_MARKUP_ERROR_INVALID_CONTENT },
++      { "<node><interface name=\"I\"><signal name=\"S\"><node><interface name=\"I2\"><signal name=\"S2\"></signal></interface></node></signal>", G_MARKUP_ERROR_INVALID_CONTENT },
++      { "<node><interface name=\"I\"><property name=\"P\" type=\"s\" access=\"read\"><node><interface name=\"I2\"></interface></node></property>", G_MARKUP_ERROR_INVALID_CONTENT },
++      { "<node><interface name=\"I\"><method name=\"M\"><arg type=\"\"><node><interface name=\"I2\"><method name=\"M2\"></method></interface></node></arg>", G_MARKUP_ERROR_INVALID_CONTENT },
++    };
++
++  for (size_t i = 0; i < G_N_ELEMENTS (vectors); i++)
++    {
++      GDBusNodeInfo *node;
++      GError *local_error = NULL;
++
++      g_test_message ("Testing parsing of %s gives an error", vectors[i].xml);
++
++      node = g_dbus_node_info_new_for_xml (vectors[i].xml, &local_error);
++      g_assert_error (local_error, G_MARKUP_ERROR, (int) vectors[i].expected_error_code);
++      g_assert_null (node);
++
++      g_clear_error (&local_error);
++    }
++}
++
+ /* ---------------------------------------------------------------------------------------------------- */
+ 
+ int
+@@ -316,6 +348,7 @@ main (int   argc,
+   g_test_add_func ("/gdbus/introspection-generate", test_generate);
+   g_test_add_func ("/gdbus/introspection-default-direction", test_default_direction);
+   g_test_add_func ("/gdbus/introspection-extra-data", test_extra_data);
++  g_test_add_func ("/gdbus/introspection-invalid", test_invalid);
+ 
+   ret = session_bus_run ();
+ 
diff --git a/glib2.spec b/glib2.spec
index 6aff43d..e73d027 100644
--- a/glib2.spec
+++ b/glib2.spec
@@ -53,6 +53,9 @@ Patch:          CVE-2025-14512.patch
 # https://gitlab.gnome.org/GNOME/glib/-/merge_requests/5247
 Patch:          gdbusnameowning-releasename-warning.patch
 
+# https://gitlab.gnome.org/GNOME/glib/-/merge_requests/5156
+Patch:          CVE-2026-58016.patch
+
 BuildRequires:  gcc
 BuildRequires:  gcc-c++
 BuildRequires:  gettext