CVE-2018-12633

Name	CVE-2018-12633
Description	An issue was discovered in the Linux kernel through 4.17.2. vbg_misc_device_ioctl() in drivers/virt/vboxguest/vboxguest_linux.c reads the same user data twice with copy_from_user. The header part of the user data is double-fetched, and a malicious user thread can tamper with the critical variables (hdr.size_in and hdr.size_out) in the header between the two fetches because of a race condition, leading to severe kernel errors, such as buffer over-accesses. This bug can cause a local denial of service and information leakage.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, 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)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.234-1	fixed
	bookworm	6.1.129-1	fixed
	bookworm (security)	6.1.135-1	fixed
	trixie	6.12.25-1	fixed
	sid	6.12.27-1	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)	4.17.3-1

Notes

[stretch] - linux <not-affected> (Vulnerable code not present)
[jessie] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/bd23a7269834dc7c1f93e83535d16ebc44b75eba (4.18-rc1)
https://bugzilla.kernel.org/show_bug.cgi?id=200131