net: fix UaF in netns ops registration error path
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 v5.10.166 by commit d4c008f3b7f7d4ffd311eb2dae5e75b3cbddacd0, it was introduced in version v5.10.153 by commit c3edc6e808209aa705185f732e682a370981ced1. For more details please see the references link.