CVE-2023-53543

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.

A missing Netlink policy entry for VDPA_ATTR_DEV_NET_CFG_MAX_VQP allowed malformed Netlink messages to bypass length validation and trigger out-of-bounds reads during attribute parsing. Exploitation requires local Netlink access (typically CAP_NET_ADMIN).

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.