CVE-2026-31470 PUBLISHED

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

Assigner: Linux
Reserved: 09.03.2026 Published: 22.04.2026 Updated: 22.04.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from f4738f56d1dc62aaba69b33702a5ab098f1b8c63 to a079a62883e3365de592cea9f7a669d8115433b0 (excl.)
  • affected from f4738f56d1dc62aaba69b33702a5ab098f1b8c63 to 6f3c8795ae9ba74fa10fe979293d1904712d3fb1 (excl.)
  • affected from f4738f56d1dc62aaba69b33702a5ab098f1b8c63 to 02ca2d9d197723696cb9cc0cb159eb7e8bf5f89b (excl.)
  • affected from f4738f56d1dc62aaba69b33702a5ab098f1b8c63 to c3fd16c3b98ed726294feab2f94f876290bf7b61 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.7 is affected
  • unaffected from 0 to 6.7 (excl.)
  • unaffected from 6.12.80 to 6.12.* (incl.)
  • unaffected from 6.18.21 to 6.18.* (incl.)
  • unaffected from 6.19.11 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References