CVE-2016-5195

Published: 19 October 2016

Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect handling of a copy-on-write (COW) feature to write to a read-only memory mapping, as exploited in the wild in October 2016, aka "Dirty COW."

From the Ubuntu Security Team

It was discovered that a race condition existed in the memory manager of the Linux kernel when handling copy-on-write breakage of private read-only memory mappings. A local attacker could use this to 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

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

Priority

Cvss 3 Severity Score

7.8

Score breakdown

Status

Package	Release	Status
linux-armadaxp Launchpad, Ubuntu, Debian	zesty	Does not exist
	upstream	Released (4.9~rc2)
	precise	Released (3.2.0-1677.104)
	trusty	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	trusty	Not vulnerable (4.4.0-1002.2)
	xenial	Not vulnerable (4.4.0-1001.10)
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
	precise	Does not exist
linux-flo Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	xenial	Ignored (abandoned)
	yakkety	Ignored (end of life)
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-gke Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Not vulnerable (4.4.0-1003.3)
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-goldfish Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	xenial	Ignored (abandoned)
	yakkety	Ignored (end of life)
	zesty	Ignored (end of life)
	upstream	Released (4.9~rc2)
linux-grouper Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-hwe Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-hwe-edge Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-linaro-shared Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-linaro-vexpress Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-lts-quantal Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
	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
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-lts-saucy Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
	This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty Launchpad, Ubuntu, Debian	precise	Released (3.13.0-100.147~precise1)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-lts-utopic Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored [end of standard support])
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-lts-vivid Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Released (3.19.0-73.81~14.04.1)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-lts-wily Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored [end of standard support])
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-lts-xenial Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Released (4.4.0-45.66~14.04.1)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-maguro Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-mako Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	xenial	Ignored (abandoned)
	yakkety	Ignored (end of life)
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-manta Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-qcm-msm Launchpad, Ubuntu, Debian	precise	Ignored (end of life)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	upstream	Released (4.9~rc2)
linux-raspi2 Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Released (4.4.0-1029.36)
	yakkety	Released (4.8.0-1018.21)
	zesty	Not vulnerable (4.8.0-1017.20)
	upstream	Released (4.9~rc2)
linux-snapdragon Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	xenial	Released (4.4.0-1032.36)
	yakkety	Released (4.4.0-1032.36)
	zesty	Not vulnerable (4.4.0-1032.36)
	upstream	Released (4.9~rc2)
linux Launchpad, Ubuntu, Debian	upstream	Released (4.9~rc2)
	precise	Released (3.2.0-115.157)
	trusty	Released (3.13.0-100.147)
	xenial	Released (4.4.0-45.66)
	yakkety	Released (4.8.0-26.28)
	zesty	Not vulnerable (4.8.0-26.28)
	Patches: Introduced by 0a27a14a62921b438bb6f33772690d345a089be6 Fixed by 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619
linux-linaro-omap Launchpad, Ubuntu, Debian	upstream	Released (4.9~rc2)
	precise	Ignored (end of life)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-ti-omap4 Launchpad, Ubuntu, Debian	upstream	Released (4.9~rc2)
	precise	Released (3.2.0-1493.120)
	trusty	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist

Severity score breakdown

Parameter	Value
Base score	7.8
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Bugs

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1633547

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