CVE-2026-31470

In the Linux kernel, the following vulnerability has been resolved:

virt: tdx-guest: Fix handling of host controlled 'quote' buffer length

Validate host controlled value `quote_buf->out_len` that determines how

many bytes of the quote are copied out to guest userspace. In TDX

environments with remote attestation, quotes are not considered private,

and can be forwarded to an attestation server.

Catch scenarios where the host specifies a response length larger than

the guest's allocation, or otherwise races modifying the response while

the guest consumes it.

This prevents contents beyond the pages allocated for `quote_buf`

(up to TSM_REPORT_OUTBLOB_MAX) from being read out to guest userspace,

and possibly forwarded in attestation requests.

Recall that some deployments want per-container configs-tsm-report

interfaces, so the leak may cross container protection boundaries, not

just local root.