CVE-2026-45851
efi: Fix reservation of unaccepted memory table
In the Linux kernel, the following vulnerability has been resolved: efi: Fix reservation of unaccepted memory table The reserve_unaccepted() function incorrectly calculates the size of the memblock reservation for the unaccepted memory table. It aligns the size of the table, but fails to account for cases where the table's starting physical address (efi.unaccepted) is not page-aligned. If the table starts at an offset within a page and its end crosses into a subsequent page that the aligned size does not cover, the end of the table will not be reserved. This can lead to the table being overwritten or inaccessible, causing a kernel panic in accept_memory(). This issue was observed when starting Intel TDX VMs with specific memory sizes (e.g., > 64GB). Fix this by calculating the end address first (including the unaligned start) and then aligning it up, ensuring the entire range is covered by the reservation.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ 8dbe33956d96c9d066ef15ca933ede30748198b2; < b7bc182ec1846be437351e44164089d988f9d0dd (affected, git) ≥ 8dbe33956d96c9d066ef15ca933ede30748198b2; < ba6b6f1502fa55621d1db23f253d54322bdbe4e0 (affected, git) ≥ 8dbe33956d96c9d066ef15ca933ede30748198b2; < 9b18bf59977f5c5bc3b11b210520f62500a7adf3 (affected, git) ≥ 8dbe33956d96c9d066ef15ca933ede30748198b2; < e649b5916725c68f44ebf45fb396df563c5dbaf2 (affected, git) ≥ 8dbe33956d96c9d066ef15ca933ede30748198b2; < 0862438c90487e79822d5647f854977d50381505 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
6.6 (affected) ≥ 0; < 6.6 (unaffected, semver) ≥ 6.6.128; ≤ 6.6.* (unaffected, semver) ≥ 6.12.75; ≤ 6.12.* (unaffected, semver) ≥ 6.18.14; ≤ 6.18.* (unaffected, semver) ≥ 6.19.4; ≤ 6.19.* (unaffected, semver) ≥ 7.0; ≤ * (unaffected, original_commit_for_fix) Other versions: affected |
CNA: Linux |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://git.kernel.org/stable/c/b7bc182ec1846be437351e44164089d988f9d0ddCNA: Linux
- https://git.kernel.org/stable/c/ba6b6f1502fa55621d1db23f253d54322bdbe4e0CNA: Linux
- https://git.kernel.org/stable/c/9b18bf59977f5c5bc3b11b210520f62500a7adf3CNA: Linux
- https://git.kernel.org/stable/c/e649b5916725c68f44ebf45fb396df563c5dbaf2CNA: Linux
- https://git.kernel.org/stable/c/0862438c90487e79822d5647f854977d50381505CNA: Linux
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