1 files changed, 290 insertions, 0 deletions

diff --git a/meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-29499.patch b/meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-29499.patch
new file mode 100644
index 0000000000..ce90586290
--- /dev/null
+++ b/meta/recipes-core/glib-2.0/glib-2.0/CVE-2023-29499.patch
@@ -0,0 +1,290 @@
+From 5f4485c4ff57fdefb1661531788def7ca5a47328 Mon Sep 17 00:00:00 2001
+From: Philip Withnall <pwithnall@endlessos.org>
+Date: Thu, 17 Aug 2023 04:19:44 +0000
+Subject: [PATCH] gvariant-serialiser: Check offset table entry size is minimal
+
+The entries in an offset table (which is used for variable sized arrays
+and tuples containing variable sized members) are sized so that they can
+address every byte in the overall variant.
+
+The specification requires that for a variant to be in normal form, its
+offset table entries must be the minimum width such that they can
+address every byte in the variant.
+
+That minimality requirement was not checked in
+`g_variant_is_normal_form()`, leading to two different byte arrays being
+interpreted as the normal form of a given variant tree. That kind of
+confusion could potentially be exploited, and is certainly a bug.
+
+Fix it by adding the necessary checks on offset table entry width, and
+unit tests.
+
+Spotted by William Manley.
+
+Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
+
+Fixes: #2794
+
+CVE: CVE-2023-29499
+Upstream-Status: Backport from [https://gitlab.gnome.org/GNOME/glib/-/commit/5f4485c4ff57fdefb1661531788def7ca5a47328]
+Signed-off-by: Siddharth Doshi <sdoshi@mvista.com>
+---
+ glib/gvariant-serialiser.c |  19 +++-
+ glib/tests/gvariant.c      | 176 +++++++++++++++++++++++++++++++++++++
+ 2 files changed, 194 insertions(+), 1 deletion(-)
+
+diff --git a/glib/gvariant-serialiser.c b/glib/gvariant-serialiser.c
+index 0bf7243..5aa2cbc 100644
+--- a/glib/gvariant-serialiser.c
++++ b/glib/gvariant-serialiser.c
+@@ -694,6 +694,10 @@ gvs_variable_sized_array_get_frame_offsets (GVariantSerialised value)
+   out.data_size = last_end;
+   out.array = value.data + last_end;
+   out.length = offsets_array_size / out.offset_size;
++
++  if (out.length > 0 && gvs_calculate_total_size (last_end, out.length) != value.size)
++    return out;  /* offset size not minimal */
++
+   out.is_normal = TRUE;
+ 
+   return out;
+@@ -1201,6 +1205,7 @@ gvs_tuple_is_normal (GVariantSerialised value)
+   gsize length;
+   gsize offset;
+   gsize i;
++  gsize offset_table_size;
+ 
+   /* as per the comment in gvs_tuple_get_child() */
+   if G_UNLIKELY (value.data == NULL && value.size != 0)
+@@ -1305,7 +1310,19 @@ gvs_tuple_is_normal (GVariantSerialised value)
+       }
+   }
+ 
+-  return offset_ptr == offset;
++  /* @offset_ptr has been counting backwards from the end of the variant, to
++   * find the beginning of the offset table. @offset has been counting forwards
++   * from the beginning of the variant to find the end of the data. They should
++   * have met in the middle. */
++  if (offset_ptr != offset)
++    return FALSE;
++
++  offset_table_size = value.size - offset_ptr;
++  if (value.size > 0 &&
++      gvs_calculate_total_size (offset, offset_table_size / offset_size) != value.size)
++    return FALSE;  /* offset size not minimal */
++
++  return TRUE;
+ }
+ 
+ /* Variants {{{2
+diff --git a/glib/tests/gvariant.c b/glib/tests/gvariant.c
+index d640c81..4ce0e4f 100644
+--- a/glib/tests/gvariant.c
++++ b/glib/tests/gvariant.c
+@@ -5092,6 +5092,86 @@ test_normal_checking_array_offsets2 (void)
+   g_variant_unref (variant);
+ }
+ 
++/* Test that an otherwise-valid serialised GVariant is considered non-normal if
++ * its offset table entries are too wide.
++ *
++ * See §2.3.6 (Framing Offsets) of the GVariant specification. */
++static void
++test_normal_checking_array_offsets_minimal_sized (void)
++{
++  GVariantBuilder builder;
++  gsize i;
++  GVariant *aay_constructed = NULL;
++  const guint8 *data = NULL;
++  guint8 *data_owned = NULL;
++  GVariant *aay_deserialised = NULL;
++  GVariant *aay_normalised = NULL;
++
++  /* Construct an array of type aay, consisting of 128 elements which are each
++   * an empty array, i.e. `[[] * 128]`. This is chosen because the inner
++   * elements are variable sized (making the outer array variable sized, so it
++   * must have an offset table), but they are also zero-sized when serialised.
++   * So the serialised representation of @aay_constructed consists entirely of
++   * its offset table, which is entirely zeroes.
++   *
++   * The array is chosen to be 128 elements long because that means offset
++   * table entries which are 1 byte long. If the elements in the array were
++   * non-zero-sized (to the extent that the overall array is ≥256 bytes long),
++   * the offset table entries would end up being 2 bytes long. */
++  g_variant_builder_init (&builder, G_VARIANT_TYPE ("aay"));
++
++  for (i = 0; i < 128; i++)
++    g_variant_builder_add_value (&builder, g_variant_new_array (G_VARIANT_TYPE_BYTE, NULL, 0));
++
++  aay_constructed = g_variant_builder_end (&builder);
++
++  /* Verify that the constructed array is in normal form, and its serialised
++   * form is `b'\0' * 128`. */
++  g_assert_true (g_variant_is_normal_form (aay_constructed));
++  g_assert_cmpuint (g_variant_n_children (aay_constructed), ==, 128);
++  g_assert_cmpuint (g_variant_get_size (aay_constructed), ==, 128);
++
++  data = g_variant_get_data (aay_constructed);
++  for (i = 0; i < g_variant_get_size (aay_constructed); i++)
++    g_assert_cmpuint (data[i], ==, 0);
++
++  /* Construct a serialised `aay` GVariant which is `b'\0' * 256`. This has to
++   * be a non-normal form of `[[] * 128]`, with 2-byte-long offset table
++   * entries, because each offset table entry has to be able to reference all of
++   * the byte boundaries in the container. All the entries in the offset table
++   * are zero, so all the elements of the array are zero-sized. */
++  data = data_owned = g_malloc0 (256);
++  aay_deserialised = g_variant_new_from_data (G_VARIANT_TYPE ("aay"),
++                                              data,
++                                              256,
++                                              FALSE,
++                                              g_free,
++                                              g_steal_pointer (&data_owned));
++
++  g_assert_false (g_variant_is_normal_form (aay_deserialised));
++  g_assert_cmpuint (g_variant_n_children (aay_deserialised), ==, 128);
++  g_assert_cmpuint (g_variant_get_size (aay_deserialised), ==, 256);
++
++  data = g_variant_get_data (aay_deserialised);
++  for (i = 0; i < g_variant_get_size (aay_deserialised); i++)
++    g_assert_cmpuint (data[i], ==, 0);
++
++  /* Get its normal form. That should change the serialised size. */
++  aay_normalised = g_variant_get_normal_form (aay_deserialised);
++
++  g_assert_true (g_variant_is_normal_form (aay_normalised));
++  g_assert_cmpuint (g_variant_n_children (aay_normalised), ==, 128);
++  g_assert_cmpuint (g_variant_get_size (aay_normalised), ==, 128);
++
++  data = g_variant_get_data (aay_normalised);
++  for (i = 0; i < g_variant_get_size (aay_normalised); i++)
++    g_assert_cmpuint (data[i], ==, 0);
++
++  g_variant_unref (aay_normalised);
++  g_variant_unref (aay_deserialised);
++  g_variant_unref (aay_constructed);
++}
++
+ /* Test that a tuple with invalidly large values in its offset table is
+  * normalised successfully without looping infinitely. */
+ static void
+@@ -5286,6 +5366,98 @@ test_normal_checking_tuple_offsets4 (void)
+   g_variant_unref (variant);
+ }
+ 
++/* Test that an otherwise-valid serialised GVariant is considered non-normal if
++ * its offset table entries are too wide.
++ *
++ * See §2.3.6 (Framing Offsets) of the GVariant specification. */
++static void
++test_normal_checking_tuple_offsets_minimal_sized (void)
++{
++  GString *type_string = NULL;
++  GVariantBuilder builder;
++  gsize i;
++  GVariant *ray_constructed = NULL;
++  const guint8 *data = NULL;
++  guint8 *data_owned = NULL;
++  GVariant *ray_deserialised = NULL;
++  GVariant *ray_normalised = NULL;
++
++  /* Construct a tuple of type (ay…ay), consisting of 129 members which are each
++   * an empty array, i.e. `([] * 129)`. This is chosen because the inner
++   * members are variable sized, so the outer tuple must have an offset table,
++   * but they are also zero-sized when serialised. So the serialised
++   * representation of @ray_constructed consists entirely of its offset table,
++   * which is entirely zeroes.
++   *
++   * The tuple is chosen to be 129 members long because that means it has 128
++   * offset table entries which are 1 byte long each. If the members in the
++   * tuple were non-zero-sized (to the extent that the overall tuple is ≥256
++   * bytes long), the offset table entries would end up being 2 bytes long.
++   *
++   * 129 members are used unlike 128 array elements in
++   * test_normal_checking_array_offsets_minimal_sized(), because the last member
++   * in a tuple never needs an offset table entry. */
++  type_string = g_string_new ("");
++  g_string_append_c (type_string, '(');
++  for (i = 0; i < 129; i++)
++    g_string_append (type_string, "ay");
++  g_string_append_c (type_string, ')');
++
++  g_variant_builder_init (&builder, G_VARIANT_TYPE (type_string->str));
++
++  for (i = 0; i < 129; i++)
++    g_variant_builder_add_value (&builder, g_variant_new_array (G_VARIANT_TYPE_BYTE, NULL, 0));
++
++  ray_constructed = g_variant_builder_end (&builder);
++
++  /* Verify that the constructed tuple is in normal form, and its serialised
++   * form is `b'\0' * 128`. */
++  g_assert_true (g_variant_is_normal_form (ray_constructed));
++  g_assert_cmpuint (g_variant_n_children (ray_constructed), ==, 129);
++  g_assert_cmpuint (g_variant_get_size (ray_constructed), ==, 128);
++
++  data = g_variant_get_data (ray_constructed);
++  for (i = 0; i < g_variant_get_size (ray_constructed); i++)
++    g_assert_cmpuint (data[i], ==, 0);
++
++  /* Construct a serialised `(ay…ay)` GVariant which is `b'\0' * 256`. This has
++   * to be a non-normal form of `([] * 129)`, with 2-byte-long offset table
++   * entries, because each offset table entry has to be able to reference all of
++   * the byte boundaries in the container. All the entries in the offset table
++   * are zero, so all the members of the tuple are zero-sized. */
++  data = data_owned = g_malloc0 (256);
++  ray_deserialised = g_variant_new_from_data (G_VARIANT_TYPE (type_string->str),
++                                              data,
++                                              256,
++                                              FALSE,
++                                              g_free,
++                                              g_steal_pointer (&data_owned));
++
++  g_assert_false (g_variant_is_normal_form (ray_deserialised));
++  g_assert_cmpuint (g_variant_n_children (ray_deserialised), ==, 129);
++  g_assert_cmpuint (g_variant_get_size (ray_deserialised), ==, 256);
++
++  data = g_variant_get_data (ray_deserialised);
++  for (i = 0; i < g_variant_get_size (ray_deserialised); i++)
++    g_assert_cmpuint (data[i], ==, 0);
++
++  /* Get its normal form. That should change the serialised size. */
++  ray_normalised = g_variant_get_normal_form (ray_deserialised);
++
++  g_assert_true (g_variant_is_normal_form (ray_normalised));
++  g_assert_cmpuint (g_variant_n_children (ray_normalised), ==, 129);
++  g_assert_cmpuint (g_variant_get_size (ray_normalised), ==, 128);
++
++  data = g_variant_get_data (ray_normalised);
++  for (i = 0; i < g_variant_get_size (ray_normalised); i++)
++    g_assert_cmpuint (data[i], ==, 0);
++
++  g_variant_unref (ray_normalised);
++  g_variant_unref (ray_deserialised);
++  g_variant_unref (ray_constructed);
++  g_string_free (type_string, TRUE);
++}
++
+ /* Test that an empty object path is normalised successfully to the base object
+  * path, ‘/’. */
+ static void
+@@ -5431,6 +5603,8 @@ main (int argc, char **argv)
+                    test_normal_checking_array_offsets);
+   g_test_add_func ("/gvariant/normal-checking/array-offsets2",
+                    test_normal_checking_array_offsets2);
++  g_test_add_func ("/gvariant/normal-checking/array-offsets/minimal-sized",
++                   test_normal_checking_array_offsets_minimal_sized);
+   g_test_add_func ("/gvariant/normal-checking/tuple-offsets",
+                    test_normal_checking_tuple_offsets);
+   g_test_add_func ("/gvariant/normal-checking/tuple-offsets2",
+@@ -5439,6 +5613,8 @@ main (int argc, char **argv)
+                    test_normal_checking_tuple_offsets3);
+   g_test_add_func ("/gvariant/normal-checking/tuple-offsets4",
+                    test_normal_checking_tuple_offsets4);
++  g_test_add_func ("/gvariant/normal-checking/tuple-offsets/minimal-sized",
++                   test_normal_checking_tuple_offsets_minimal_sized);
+   g_test_add_func ("/gvariant/normal-checking/empty-object-path",
+                    test_normal_checking_empty_object_path);
+ 
+-- 
+2.24.4
+