CVE-2018-17205

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6,
affecting ofproto_rule_insert__ in ofproto/ofproto.c. During bundle commit,
flows that are added in a bundle are applied to ofproto in order. If a flow
cannot be added (e.g., the flow action is a go-to for a group id that does
not exist), OvS tries to revert back all previous flows that were
successfully applied from the same bundle. This is possible since OvS
maintains list of old flows that were replaced by flows from the bundle.
While reinserting old flows, OvS has an assertion failure due to a check on
rule state != RULE_INITIALIZED. This would work for new flows, but for an
old flow the rule state is RULE_REMOVED. The assertion failure causes an
OvS crash.