Linux Kernel Vulnerability in KVM Affecting Address Space Write Tracking

CVE-2026-98164

What is CVE-2026-98164?

A vulnerability in the Linux kernel's KVM component allows improper write tracking across different address spaces. The function kvm_gfn_is_write_tracked() checked only a single memory slot, leading to potential exploitation where a guest frame number (GFN) could be write-tracked in one address space but appear untracked in another. This flaw could affect the integrity of memory operations and lead to incorrect synchronization of pages across address spaces, ultimately causing unexpected behavior in virtualized environments. Implementing checks within the address spaces ensures that all memory operations respect write tracking, preventing potential disruptions in system functionality.

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