File 0006-gdbusmessage-Validate-type-of-message-header-signatu.patch of Package glib2.11799
From bef07b9c22e2f2127ae2c7cb5ac9a6568be39509 Mon Sep 17 00:00:00 2001
From: Philip Withnall <withnall@endlessm.com>
Date: Thu, 16 Aug 2018 21:33:52 +0100
Subject: [PATCH 06/15] gdbusmessage: Validate type of message header signature
field
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Parsing a D-Bus message with the signature field in the message header
of type other than ‘g’ (GVariant type signature) would cause a critical
warning. Instead, we should return a runtime error.
Includes a test.
oss-fuzz#9825
Signed-off-by: Philip Withnall <withnall@endlessm.com>
---
gio/gdbusmessage.c | 19 ++++++++++++++
gio/tests/gdbus-serialization.c | 56 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 75 insertions(+)
diff --git a/gio/gdbusmessage.c b/gio/gdbusmessage.c
index 8de836bf6..79bc11c16 100644
--- a/gio/gdbusmessage.c
+++ b/gio/gdbusmessage.c
@@ -2115,6 +2115,15 @@ g_dbus_message_new_from_blob (guchar *blob,
const gchar *signature_str;
gsize signature_str_len;
+ if (!g_variant_is_of_type (signature, G_VARIANT_TYPE_SIGNATURE))
+ {
+ g_set_error_literal (error,
+ G_IO_ERROR,
+ G_IO_ERROR_INVALID_ARGUMENT,
+ _("Signature header found but is not of type signature"));
+ goto out;
+ }
+
signature_str = g_variant_get_string (signature, &signature_str_len);
/* signature but no body */
@@ -2695,6 +2704,16 @@ g_dbus_message_to_blob (GDBusMessage *message,
body_start_offset = mbuf.valid_len;
signature = g_dbus_message_get_header (message, G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE);
+
+ if (signature != NULL && !g_variant_is_of_type (signature, G_VARIANT_TYPE_SIGNATURE))
+ {
+ g_set_error_literal (error,
+ G_IO_ERROR,
+ G_IO_ERROR_INVALID_ARGUMENT,
+ _("Signature header found but is not of type signature"));
+ goto out;
+ }
+
signature_str = NULL;
if (signature != NULL)
signature_str = g_variant_get_string (signature, NULL);
diff --git a/gio/tests/gdbus-serialization.c b/gio/tests/gdbus-serialization.c
index 2ab856c48..3cdade6d7 100644
--- a/gio/tests/gdbus-serialization.c
+++ b/gio/tests/gdbus-serialization.c
@@ -873,6 +873,20 @@ message_serialize_header_checks (void)
g_assert (blob == NULL);
g_object_unref (message);
+ /*
+ * check that we can't serialize messages with SIGNATURE set to a non-signature-typed value
+ */
+ message = g_dbus_message_new_signal ("/the/path", "The.Interface", "TheMember");
+ g_dbus_message_set_header (message, G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE, g_variant_new_boolean (FALSE));
+ blob = g_dbus_message_to_blob (message, &blob_size, G_DBUS_CAPABILITY_FLAGS_NONE, &error);
+
+ g_assert_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT);
+ g_assert_cmpstr (error->message, ==, "Signature header found but is not of type signature");
+ g_assert_null (blob);
+
+ g_clear_error (&error);
+ g_clear_object (&message);
+
/*
* check we can't serialize signal messages with INTERFACE, PATH or MEMBER unset / set to reserved value
*/
@@ -1083,6 +1097,46 @@ test_double_array (void)
/* ---------------------------------------------------------------------------------------------------- */
+/* Test that an invalid header in a D-Bus message (specifically, with a type
+ * which doesn’t match what’s expected for the given header) is gracefully
+ * handled with an error rather than a crash.
+ * The set of bytes here come directly from fuzzer output. */
+static void
+test_message_parse_non_signature_header (void)
+{
+ const guint8 data[] = {
+ 0x6c, /* byte order */
+ 0x04, /* message type */
+ 0x0f, /* message flags */
+ 0x01, /* major protocol version */
+ 0x00, 0x00, 0x00, 0x00, /* body length */
+ 0x00, 0x00, 0x00, 0xbc, /* message serial */
+ /* a{yv} of header fields:
+ * (things start to be invalid below here) */
+ 0x02, 0x00, 0x00, 0x00, /* array length (in bytes) */
+ G_DBUS_MESSAGE_HEADER_FIELD_SIGNATURE, /* array key */
+ /* GVariant array value: */
+ 0x04, /* signature length */
+ 'd', 0x00, 0x00, 'F', /* signature (invalid) */
+ 0x00, /* nul terminator */
+ /* (GVariant array value payload missing) */
+ /* (message body length missing) */
+ };
+ gsize size = sizeof (data);
+ GDBusMessage *message = NULL;
+ GError *local_error = NULL;
+
+ message = g_dbus_message_new_from_blob ((guchar *) data, size,
+ G_DBUS_CAPABILITY_FLAGS_NONE,
+ &local_error);
+ g_assert_error (local_error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT);
+ g_assert_null (message);
+
+ g_clear_error (&local_error);
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
int
main (int argc,
char *argv[])
@@ -1102,6 +1156,8 @@ main (int argc,
message_parse_empty_arrays_of_arrays);
g_test_add_func ("/gdbus/message-serialize/double-array", test_double_array);
+ g_test_add_func ("/gdbus/message-parse/non-signature-header",
+ test_message_parse_non_signature_header);
return g_test_run();
}
--
2.14.4
