vdpa: Add max vqp attr to vdpa_nl_policy for nlattr length check

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: vdpa: Add max vqp 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 max vqp attr to avoid such bugs.

References

• https://git.kernel.org/stable/c/baed19c108ac8287425b93a44985bbe9a0b1af8d
• https://git.kernel.org/stable/c/ff71709445ac033e6e250d971683110e4781c068
• https://git.kernel.org/stable/c/ea65e8b5e6b1a34deda7564f09c90e9e80db436a
• https://git.kernel.org/stable/c/5d6ba607d6cb5c58a4ddf33381e18c83dbb4098f