This fast-path previously did not check that the array was made up
of an integer number of items. This could lead to assertion failures
and out-of-bounds accesses during subsequent message processing (which
assumes that the message has already been validated), particularly after
the addition of _dbus_header_remove_unknown_fields(), which makes it
more likely that dbus-daemon will apply non-trivial edits to messages.
Thanks: Evgeny Vereshchagin
Fixes:
e61f13cf "Bug 18064 - more efficient validation for fixed-size type arrays"
Resolves: https://gitlab.freedesktop.org/dbus/dbus/-/issues/413
Resolves: CVE-2022-42011
Signed-off-by: Simon McVittie <smcv@collabora.com>
(cherry picked from commit
079bbf16186e87fb0157adf8951f19864bc2ed69)
(cherry picked from commit
b9e6a7523085a2cfceaffca7ba1ab4251f12a984)
Signed-off-by: Unsung Lee <unsung.lee@samsung.com>
Change-Id: Idfe8cead0721c414f1e6946a5dc0544bad63d42e
*/
if (dbus_type_is_fixed (array_elem_type))
{
+ /* Note that fixed-size types all have sizes equal to
+ * their alignments, so this is really the item size. */
+ alignment = _dbus_type_get_alignment (array_elem_type);
+ _dbus_assert (alignment == 1 || alignment == 2 ||
+ alignment == 4 || alignment == 8);
+
+ /* Because the alignment is a power of 2, this is
+ * equivalent to: (claimed_len % alignment) != 0,
+ * but avoids slower integer division */
+ if ((claimed_len & (alignment - 1)) != 0)
+ return DBUS_INVALID_ARRAY_LENGTH_INCORRECT;
+
/* bools need to be handled differently, because they can
* have an invalid value
*/
if (array_elem_type == DBUS_TYPE_BOOLEAN)
{
dbus_uint32_t v;
- alignment = _dbus_type_get_alignment (array_elem_type);
while (p < array_end)
{