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mirror of https://github.com/systemd/systemd-stable.git synced 2025-01-11 05:17:44 +03:00

sd-netlink: make sure the root-level type is nested

In sd-netlink-message, we always guarantee that the currently selected
type-system is non-NULL. Otherwise, we would be unable to parse any types
in the current container level. Hence, this assertion must be true:
    message->container_type_system[m->n_containers] != NULL

During message_new() we currently do not verify that this assertion is
true. Instead, we blindly access nl_type->type_system and use it (which
might be NULL for basic types and unions). Fix this, by explicitly
checking that the root-level type is nested.

Note that this is *not* a strict requirement of netlink, but it's a strict
requirement for all message types we currently support. Furthermore, all
the callers of message_new() already verify that only supported types are
passed, therefore, this is a pure cosmetic check. However, it might be
needed on the future, so make sure we don't trap into this once we change
the type-system.
This commit is contained in:
David Herrmann 2015-06-23 10:47:44 +02:00
parent 979e7eb9cc
commit 12b7dff45b

View File

@ -72,6 +72,9 @@ int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) {
if (r < 0)
return r;
if (type_get_type(nl_type) != NETLINK_TYPE_NESTED)
return -EINVAL;
r = message_new_empty(rtnl, &m);
if (r < 0)
return r;
@ -85,8 +88,7 @@ int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) {
m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
if (type_get_type(nl_type) == NETLINK_TYPE_NESTED)
type_get_type_system(nl_type, &m->container_type_system[0]);
type_get_type_system(nl_type, &m->container_type_system[0]);
m->hdr->nlmsg_len = size;
m->hdr->nlmsg_type = type;