CVE-2018-18281

kernel: TLB flush happens too late on mremap

Published Oct 30, 2018 CVSS 3.0 · 7.8 High EPSS 1.1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-1715-1 linux-4.9 security update
Debian DLA Debian DLA DLA-1731-1 linux security update
Debian DLA Debian DLA DLA-1731-2 linux regression update
EUVD EUVD EUVD-2018-10016 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.
Ubuntu USN Ubuntu USN USN-3832-1 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-3835-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-3871-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-3871-3 Linux kernel (AWS, GCP, KVM, OEM, Raspberry Pi 2) vulnerabilities
Ubuntu USN Ubuntu USN USN-3871-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-3871-5 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-3880-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-3880-2 Linux kernel (Trusty HWE) vulnerabilities
History
Type Values Removed Values Added
Metrics epss

{'score': 0.00269}

epss

{'score': 0.00283}