memcg: fix possible use-after-free in memcgwriteevent_control()
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v4.14.302 by commit b77600e26fd48727a95ffd50ba1e937efb548125, it was introduced in version v3.14 by commit 347c4a8747104a945ecced358944e42879176ca5. For more details please see the references link.