CVE-2018-18397

Name	CVE-2018-18397
Description	The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file, and that file contains holes), related to fs/userfaultfd.c and mm/userfaultfd.c.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	buster	4.19.249-2	fixed
	buster (security)	4.19.282-1	fixed
	bullseye	5.10.178-3	fixed
	bullseye (security)	5.10.179-1	fixed
	bookworm, sid	6.1.27-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
linux	source	jessie	(not affected)
linux	source	stretch	(not affected)
linux	source	(unstable)	4.19.9-1

Notes

[stretch] - linux <not-affected> (Vulnerable code not present)
[jessie] - linux <not-affected> (Vulnerable code not present)
https://lore.kernel.org/lkml/20181126173452.26955-1-aarcange@redhat.com/T/#u
https://bugs.chromium.org/p/project-zero/issues/detail?id=1700