A security flaw was found in the Linux kernel in a way that the cleancache subsystem clears an inode after the final file truncation (removal). The new file created with the same inode may contain leftover pages from cleancache and the old file data instead of the new one.
http://www.securityfocus.com/bid/106009
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16862
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html
https://lists.debian.org/debian-lts-announce/2019/03/msg00034.html
https://lists.debian.org/debian-lts-announce/2019/04/msg00004.html
https://lore.kernel.org/patchwork/patch/1011367/
https://seclists.org/oss-sec/2018/q4/169
https://usn.ubuntu.com/3879-1/
https://usn.ubuntu.com/3879-2/
Source: MITRE
Published: 2018-11-26
Updated: 2019-04-01
Type: CWE-200
Base Score: 2.1
Vector: AV:L/AC:L/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 3.9
Severity: LOW
Base Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM