CVE-2026-98164
Published: September 30, 2026Last modified: October 6, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Check write tracking in all address spaces kvm_gfn_is_write_tracked() checks only the supplied memslot, but page tracking is per-address-space and shadow pages are shared across all address spaces. With SMM, a GFN can therefore be write-tracked in one address space and appear untracked through the other. Check the supplied slot first, then the slot for the other address space. This ensures all callers honor write tracking regardless of the active address space. In particular, it prevents mmu_try_to_unsync_pages() from marking an upper-level shadow page unsync and eventually triggering the BUG in pte_list_remove(). [invert direction of the conditional. - Paolo]
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.189-r0) |
| 25 LTS | linux-lts | Fixed (6.12.111-r0) | |
| Stream | linux-lts | Fixed (6.18.53-r0) |
References
- https://git.kernel.org/stable/c/09aa68552d2542cc6c23edd1568ac265dc5d886f
- https://git.kernel.org/stable/c/0f38453cdb2e17566ccb7c0f3dabd5bd21caca26
- https://git.kernel.org/stable/c/429b6f43b4d8c98988fdca99e02dc156134e3d77
- https://git.kernel.org/stable/c/c0a9bd5fca0b5f2dea32b0fc31350e71e8648112
- https://git.kernel.org/stable/c/d8636c8f9f95d0fd1e2f6f1cad0d5757aa6f212a
- https://git.kernel.org/stable/c/ec8fcaf354c1cbb36755d48e9f5a00c9591349e5