Stale TLB Entry Vulnerability in Linux Kernel

CVE-2018-18281 · MEDIUM Severity

AV:L/AC:L/AU:N/C:P/I:P/A:P

Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused. This is fixed in the following kernel versions: 4.9.135, 4.14.78, 4.18.16, 4.19.

Learn more about our Cis Benchmark Audit For Distribution Independent Linux.