CVE-2026-98164

Summary

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]

Affected Software

VendorProductVersion RangeStatus
LinuxLinux699023e239658e62da6f42f47d31b54788521ec1 < 09aa68552d2542cc6c23edd1568ac265dc5d886faffected
LinuxLinux699023e239658e62da6f42f47d31b54788521ec1 < 429b6f43b4d8c98988fdca99e02dc156134e3d77affected
LinuxLinux699023e239658e62da6f42f47d31b54788521ec1 < d8636c8f9f95d0fd1e2f6f1cad0d5757aa6f212aaffected
LinuxLinux699023e239658e62da6f42f47d31b54788521ec1 < c0a9bd5fca0b5f2dea32b0fc31350e71e8648112affected
LinuxLinux699023e239658e62da6f42f47d31b54788521ec1 < ec8fcaf354c1cbb36755d48e9f5a00c9591349e5affected
LinuxLinux699023e239658e62da6f42f47d31b54788521ec1 < 0f38453cdb2e17566ccb7c0f3dabd5bd21caca26affected
LinuxLinux4.2affected
LinuxLinux0 < 4.2unaffected
LinuxLinux6.1.187 <= 6.1.*unaffected
LinuxLinux6.6.156 <= 6.6.*unaffected
LinuxLinux6.12.108 <= 6.12.*unaffected
LinuxLinux6.18.49 <= 6.18.*unaffected
LinuxLinux7.1.13 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References