CVE-2019-3887

Name	CVE-2019-3887
Description	A flaw was found in the way KVM hypervisor handled x2APIC Machine Specific Rregister (MSR) access with nested(=1) virtualization enabled. In that, L1 guest could access L0's APIC register values via L2 guest, when 'virtualize x2APIC mode' is enabled. A guest could use this flaw to potentially crash the host kernel resulting in DoS issue. Kernel versions from 4.16 and newer are vulnerable to this issue.
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)	4.19.269-1	fixed
	bullseye	5.10.158-2	fixed
	bullseye (security)	5.10.162-1	fixed
	bookworm	6.1.15-1	fixed
	sid	6.1.20-1	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)	4.19.37-1

Notes

[stretch] - linux <not-affected> (Vulnerability introduced later)
[jessie] - linux <not-affected> (Vulnerability introduced later)
Fixed by: https://git.kernel.org/linus/acff78477b9b4f26ecdf65733a4ed77fe837e9dc
Fixed by: https://git.kernel.org/linus/c73f4c998e1fd4249b9edfa39e23f4fda2b9b041