CVE-2016-4558

The BPF subsystem in the Linux kernel before 4.5.5 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted application on (1) a system with more than 32 Gb of memory, related to the program reference count or (2) a 1 Tb system, related to the map reference count.

From the Ubuntu Security Team

Jann Horn discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel could overflow reference counters on systems with more than 32GB of physical ram and with RLIMIT_MEMLOCK set to infinite. A local unprivileged attacker could use to create a use-after- free situation, causing a denial of service (system crash) or possibly gain administrative privileges.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
linux	16.10 yakkety	Not affected
	16.04 LTS xenial	Fixed 4.4.0-24.43
	15.10 wily	Not affected
	14.04 LTS trusty	Not affected
	12.04 LTS precise	Not affected
linux-armadaxp	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not affected
linux-aws	16.10 yakkety	Not in release
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
	12.04 LTS precise	Not in release
linux-flo	16.10 yakkety	Not affected
	16.04 LTS xenial	Not affected
	15.10 wily	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-gke	16.10 yakkety	Not in release
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-goldfish	16.10 yakkety	Not affected
	16.04 LTS xenial	Not affected
	15.10 wily	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-grouper	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-hwe	16.10 yakkety	Not in release
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-hwe-edge	16.10 yakkety	Not in release
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-linaro-omap	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-linaro-shared	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-linaro-vexpress	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-lts-quantal	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-lts-raring	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-lts-saucy	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-lts-trusty	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not affected
linux-lts-utopic	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-lts-vivid	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-lts-wily	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-lts-xenial	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Fixed 4.4.0-24.43~14.04.1
	12.04 LTS precise	Not in release
linux-maguro	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-mako	16.10 yakkety	Not affected
	16.04 LTS xenial	Not affected
	15.10 wily	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-manta	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-qcm-msm	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Ignored end of life
linux-raspi2	16.10 yakkety	Not affected
	16.04 LTS xenial	Fixed 4.4.0-1012.16
	15.10 wily	Not affected
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-snapdragon	16.10 yakkety	Not affected
	16.04 LTS xenial	Fixed 4.4.0-1015.18
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release
linux-ti-omap4	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not affected

Notes

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

made exploitable by unpriv bpf

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
linux	Introduced by 1be7f75, fixed by 92117d8

Severity score breakdown

Parameter	Value
Base score	7.0 · High
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

USN-3005-1
Linux kernel (Xenial HWE) vulnerabilities
10 June 2016

USN-3007-1
Linux kernel (Raspberry Pi 2) vulnerabilities
10 June 2016

USN-3006-1
Linux kernel vulnerabilities
10 June 2016

Cvss 3 Severity Score