UBUNTU-CVE-2018-18281
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.
02 / AFFECTED SOFTWARE
Affected packages
143 explicit affected versions
24 explicit affected versions
6 explicit affected versions
64 explicit affected versions
86 explicit affected versions
45 explicit affected versions
2 explicit affected versions
29 explicit affected versions
25 explicit affected versions
45 explicit affected versions
24 explicit affected versions
58 explicit affected versions
56 explicit affected versions
23 explicit affected versions
18 explicit affected versions
20 explicit affected versions
17 explicit affected versions
18 explicit affected versions
15 explicit affected versions
20 explicit affected versions
4 explicit affected versions
26 explicit affected versions
1 explicit affected versions
1 explicit affected versions
23 explicit affected versions
1 explicit affected versions
3 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1695
- https://git.kernel.org/linus/eb66ae030829605d61fbef1909ce310e29f78821
- https://ubuntu.com/security/CVE-2018-18281
- https://ubuntu.com/security/notices/USN-3832-1
- https://ubuntu.com/security/notices/USN-3835-1
- https://ubuntu.com/security/notices/USN-3871-1
- https://ubuntu.com/security/notices/USN-3871-3
- https://ubuntu.com/security/notices/USN-3871-4
- https://ubuntu.com/security/notices/USN-3871-5
- https://ubuntu.com/security/notices/USN-3880-1
- https://ubuntu.com/security/notices/USN-3880-2
- https://www.cve.org/CVERecord?id=CVE-2018-18281