On 9/21/23 10:23, Johannes Nixdorf wrote:
On Wed, Sep 20, 2023 at 01:46:02PM +0300, Nikolay Aleksandrov wrote:On 9/19/23 11:12, Johannes Nixdorf wrote:Set any new attributes added to br_policy to be parsed strictly, to prevent userspace from passing garbage. Signed-off-by: Johannes Nixdorf <jnixdorf-oss@xxxxxx> --- net/bridge/br_netlink.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index 10f0d33d8ccf..505683ef9a26 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -1229,6 +1229,8 @@ static size_t br_port_get_slave_size(const struct net_device *brdev, } static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = { + [IFLA_BR_UNSPEC] = { .strict_start_type = + IFLA_BR_MCAST_QUERIER_STATE + 1 }, [IFLA_BR_FORWARD_DELAY] = { .type = NLA_U32 }, [IFLA_BR_HELLO_TIME] = { .type = NLA_U32 }, [IFLA_BR_MAX_AGE] = { .type = NLA_U32 },instead of IFLA_BR_MCAST_QUERIER_STATE + 1, why not move around the patch and just use the new attribute name? These are uapi, they won't change.I wanted to avoid having a state between the two commits where the new attributes are already added, but not yet strictly verified. Otherwise they would present a slightly different UAPI at that one commit boundary than after this commit.
That's not really a problem, the attribute is the same.
This is also not the only place in the kernel where strict_start_type
is specified that way. See e.g. commit c00041cf1cb8 ("net: bridge: Set
strict_start_type at two policies"), even though that seems mostly be
done to turn on strict_start_type preemtively, not in the same series
that adds the new attribute.
Please, just use the new attribute to be more explicit where the strict parsing starts.
Thanks, Nik
