CVE-2016-4558

Published: 23 May 2016

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.

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	made exploitable by unpriv bpf

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

made exploitable by unpriv bpf

Priority

Cvss 3 Severity Score

7.0

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Not vulnerable
	upstream	Released (4.6~rc7)
	wily	Not vulnerable
	xenial	Released (4.4.0-24.43)
	yakkety	Not vulnerable (4.4.0-23.41)
	Patches: Introduced by 1be7f75d1668d6296b80bf35dcf6762393530afc Fixed by 92117d8443bc5afacc8d5ba82e541946310f106e
linux-armadaxp Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
linux-gke Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
linux-linaro-omap Launchpad, Ubuntu, Debian	precise	Ignored (abandoned)
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-linaro-shared Launchpad, Ubuntu, Debian	precise	Ignored (abandoned)
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-linaro-vexpress Launchpad, Ubuntu, Debian	precise	Ignored (abandoned)
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-wily Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was not-affected)
	upstream	Released (4.6~rc7)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
linux-lts-xenial Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Released (4.4.0-24.43~14.04.1)
	upstream	Released (4.6~rc7)
	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 (4.6~rc7)
	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 (4.6~rc7)
	wily	Not vulnerable
	xenial	Not vulnerable
	yakkety	Not vulnerable
linux-manta Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.6~rc7)
	wily	Not vulnerable
	xenial	Does not exist
	yakkety	Does not exist
linux-qcm-msm Launchpad, Ubuntu, Debian	precise	Ignored (abandoned)
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	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 (4.6~rc7)
	wily	Not vulnerable
	xenial	Released (4.4.0-1012.16)
	yakkety	Not vulnerable (4.4.0-1011.14)
linux-snapdragon Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	wily	Does not exist
	xenial	Released (4.4.0-1015.18)
	yakkety	Not vulnerable (4.4.0-1014.16)
linux-ti-omap4 Launchpad, Ubuntu, Debian	precise	Not vulnerable
	trusty	Does not exist
	upstream	Released (4.6~rc7)
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist

Severity score breakdown

Parameter	Value
Base score	7.0
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Bugs

https://launchpad.net/bugs/1579140

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