vdpa: Add features attr to vdpa_nl_policy for nlattr length check

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: vdpa: Add features attr to vdpa_nl_policy for nlattr length check The vdpa_nl_policy structure is used to validate the nlattr when parsing the incoming nlmsg. It will ensure the attribute being described produces a valid nlattr pointer in info->attrs before entering into each handler in vdpa_nl_ops. That is to say, the missing part in vdpa_nl_policy may lead to illegal nlattr after parsing, which could lead to OOB read just like CVE-2023-3773. This patch adds the missing nla_policy for vdpa features attr to avoid such bugs.

References

• https://git.kernel.org/stable/c/44b508cc96889e61799cc0fc6c00766a54f3ab5a
• https://git.kernel.org/stable/c/645d17e06c502e71b880b2b854930e5a64014640
• https://git.kernel.org/stable/c/79c8651587504ba263d2fd67fd4406240fb21f69