On 10/29/2015 06:44 AM, Markus Armbruster wrote: > This would have prevented the regression mentioned in the previous > commit. > > Signed-off-by: Markus Armbruster <arm...@redhat.com> > --- > tests/check-qjson.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+)
Better late than never.
> +++ b/tests/check-qjson.c
> @@ -1484,6 +1484,34 @@ static void unterminated_literal(void)
> g_assert(obj == NULL);
> }
>
> +static char *make_nest(char *buf, size_t cnt)
> +{
> + int i;
> +
> + for (i = 0; i < cnt - 1; i++) {
> + buf[i] = '[';
> + buf[2 * cnt - i - 1] = ']';
> + }
> + buf[cnt - 1] = '{';
> + buf[cnt] = '}';
> + buf[2 * cnt] = 0;
> + return buf;
> +}
So buf must be at least 2*cnt+1 bytes long. (Function is static, so
lack of comments don't hurt too badly). For a cnt of 3 (buffer size at
least 7), this creates "[[{}]]". Larger cnt adds more outer [] pairs.
The mixed content proves that patch 1/4 covers the combined limit of []
and {} when counting nesting.
Minor optimization - make the for loop bound be 'i < cnt - 2', so you
aren't writing [] in the middle just to rewrite it to {} after the loop
(works as long as caller never passes cnt == 1, which happens to be the
case).
> +
> +static void limits_nesting(void)
> +{
> + enum { max_nesting = 1024 }; /* see qobject/json-streamer.c */
> + char buf[2 * (max_nesting + 1) + 1];
> + QObject *obj;
> +
> + obj = qobject_from_json(make_nest(buf, max_nesting));
> + g_assert(obj != NULL);
> + qobject_decref(obj);
Proves that we can hit our max,
> +
> + obj = qobject_from_json(make_nest(buf, max_nesting + 1));
> + g_assert(obj == NULL);
and that we gracefully diagnose one beyond max.
> +}
> +
> int main(int argc, char **argv)
> {
> g_test_init(&argc, &argv, NULL);
> @@ -1519,6 +1547,7 @@ int main(int argc, char **argv)
> g_test_add_func("/errors/invalid_array_comma", invalid_array_comma);
> g_test_add_func("/errors/invalid_dict_comma", invalid_dict_comma);
> g_test_add_func("/errors/unterminated/literal", unterminated_literal);
> + g_test_add_func("/errors/limits/nesting", limits_nesting);
>
> return g_test_run();
> }
>
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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