Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 3.2, < 4.9.135 |
| Canonical | Ubuntu Linux | 12.04 |
| Debian | Debian Linux | 8.0 |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/150001/Linux-mremap-TLB-Flush-Too-Late.htmlPatchThird Party AdvisoryVDB Entry
- http://www.openwall.com/lists/oss-security/2018/10/29/5Mailing ListPatchThird Party Advisory
- http://www.securityfocus.com/bid/105761Third Party AdvisoryVDB Entry
- http://www.securityfocus.com/bid/106503Third Party AdvisoryVDB Entry
- https://access.redhat.com/errata/RHSA-2019:0831
- https://access.redhat.com/errata/RHSA-2019:2029
- https://access.redhat.com/errata/RHSA-2019:2043
- https://access.redhat.com/errata/RHSA-2020:0036
- https://access.redhat.com/errata/RHSA-2020:0100
- https://access.redhat.com/errata/RHSA-2020:0103
- https://access.redhat.com/errata/RHSA-2020:0179
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1695ExploitPatchThird Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.78PatchVendor Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.16PatchVendor Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.135PatchVendor Advisory
FAQ
What is CVE-2018-18281?
CVE-2018-18281 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 ...
How severe is CVE-2018-18281?
CVE-2018-18281 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2018-18281?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Canonical Ubuntu Linux, Debian Debian Linux.