On Tue, Oct 15, 2019 at 04:16:57PM +0200, Phil Sutter wrote:
> Array 'tb' has only 'attr_max' elements, the loop overstepped its
> boundary by one. Copy array_size() macro from include/utils.h in
> nftables.git to make sure code does the right thing.
>
> Fixes: 0adceeab1597a ("src: add ct timeout support")
> Signed-off-by: Phil Sutter <[email protected]>
> ---
> include/utils.h | 8 ++++++++
> src/obj/ct_timeout.c | 2 +-
> 2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/include/utils.h b/include/utils.h
> index 3cc659652fe2e..91fbebb1956fd 100644
> --- a/include/utils.h
> +++ b/include/utils.h
> @@ -58,6 +58,14 @@ void __nftnl_assert_attr_exists(uint16_t attr, uint16_t
> attr_max,
> ret = remain; \
> remain -= ret; \
>
> +
> +#define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
> +
> +#define __must_be_array(a) \
> + BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a),
> typeof(&a[0])))
> +
> +#define array_size(arr) (sizeof(arr) / sizeof((arr)[0]) +
> __must_be_array(arr))
> +
> const char *nftnl_family2str(uint32_t family);
> int nftnl_str2family(const char *family);
>
> diff --git a/src/obj/ct_timeout.c b/src/obj/ct_timeout.c
> index a439432deee18..a09e25ae5d44f 100644
> --- a/src/obj/ct_timeout.c
> +++ b/src/obj/ct_timeout.c
> @@ -134,7 +134,7 @@ timeout_parse_attr_data(struct nftnl_obj *e,
> if (mnl_attr_parse_nested(nest, parse_timeout_attr_policy_cb, &cnt) < 0)
> return -1;
>
> - for (i = 1; i <= attr_max; i++) {
> + for (i = 1; i < array_size(tb); i++) {
Are you sure this is correct?
array use NFTNL_CTTIMEOUT_* while tb uses netlink NFTA_* attributes.
> if (tb[i]) {
> nftnl_timeout_policy_attr_set_u32(e, i-1,
> ntohl(mnl_attr_get_u32(tb[i])));
> --
> 2.23.0
>
