CVE-2016-3713

Published: 16 May 2016

The msr_mtrr_valid function in arch/x86/kvm/mtrr.c in the Linux kernel before 4.6.1 supports MSR 0x2f8, which allows guest OS users to read or write to the kvm_arch_vcpu data structure, and consequently obtain sensitive information or cause a denial of service (system crash), via a crafted ioctl call.

From the Ubuntu Security Team

David Matlack discovered that the Kernel-based Virtual Machine (KVM) implementation in the Linux kernel did not properly restrict variable Memory Type Range Registers (MTRR) in KVM guests. A privileged user in a guest VM could use this to cause a denial of service (system crash) in the host, expose sensitive information from the host, or possibly gain administrative privileges in the host.

Notes

Author	Note
jdstrand	android kernels (flo, goldfish, grouper, maguro, mako and manta) are not supported on the Ubuntu Touch 14.10 and earlier preview kernels linux-lts-saucy no longer receives official support linux-lts-quantal no longer receives official support
sbeattie	x86 issue only

Author

Note

jdstrand

android kernels (flo, goldfish, grouper, maguro, mako and manta) are
not supported on the Ubuntu Touch 14.10 and earlier preview kernels
linux-lts-saucy no longer receives official support
linux-lts-quantal no longer receives official support

sbeattie

x86 issue only

Priority

Cvss 3 Severity Score

7.1

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Not vulnerable
	upstream	Released (4.7~rc1)
	wily	Released (4.2.0-36.42)
	xenial	Released (4.4.0-22.40)
	yakkety	Not vulnerable (4.4.0-22.40)
	Patches: Introduced by 910a6aae4e2e45855efc4a268e43eed2d8445575 Fixed by 9842df62004f366b9fed2423e24df10542ee0dc5
linux-armadaxp Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-aws Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Not vulnerable (4.4.0-1002.2)
	upstream	Released (4.7~rc1)
	xenial	Not vulnerable (4.4.0-1001.10)
	yakkety	Does not exist
linux-flo Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.7~rc1)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
linux-gke Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	xenial	Not vulnerable (4.4.0-1003.3)
	yakkety	Does not exist
linux-goldfish Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.7~rc1)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
linux-grouper Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-hwe Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
linux-hwe-edge Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
linux-linaro-omap Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-linaro-shared Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-linaro-vexpress Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-quantal Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-lts-raring Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-saucy Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-utopic Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was not-affected)
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-vivid Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was not-affected)
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-wily Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Released (4.2.0-36.42~14.04.1)
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-xenial Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Released (4.4.0-22.40~14.04.1)
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-maguro Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-mako Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.7~rc1)
	wily	Not vulnerable (x86 only)
	xenial	Not vulnerable (x86 only)
	yakkety	Not vulnerable (x86 only)
linux-manta Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Not vulnerable (x86 only)
	wily	Not vulnerable (x86 only)
	xenial	Does not exist
	yakkety	Does not exist
linux-qcm-msm Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-raspi2 Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Not vulnerable (x86 only)
	xenial	Not vulnerable (x86 only)
	yakkety	Not vulnerable (x86 only)
linux-snapdragon Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Not vulnerable (x86 only)
	yakkety	Not vulnerable (x86 only)
linux-ti-omap4 Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	upstream	Released (4.7~rc1)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist

Severity score breakdown

Parameter	Value
Base score	7.1
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

References

Bugs

https://launchpad.net/bugs/1581201

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