CVE-2015-7550

Published: 30 December 2015

The keyctl_read_key function in security/keys/keyctl.c in the Linux kernel before 4.3.4 does not properly use a semaphore, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted application that leverages a race condition between keyctl_revoke and keyctl_read calls.

From the Ubuntu Security Team

It was discovered that the Linux kernel keyring subsystem contained a race between read and revoke operations. A local attacker could use this to cause a denial of service (system crash).

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

5.5

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	precise	Released (3.2.0-99.139)
	trusty	Released (3.13.0-79.123)
	upstream	Released (4.4~rc8)
	vivid	Released (3.19.0-51.57)
	wily	Released (4.2.0-27.32)
	xenial	Not vulnerable (4.4.0-2.16)
	yakkety	Not vulnerable (4.4.0-21.37)
	zesty	Not vulnerable (4.8.0-22.24)
	Patches: Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Fixed by b4a1b4f5047e4f54e194681125c74c0aa64d637d
linux-armadaxp Launchpad, Ubuntu, Debian	precise	Does not exist (precise was released [3.2.0-1662.86])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	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 (4.4~rc8)
	xenial	Not vulnerable (4.4.0-1001.10)
	yakkety	Does not exist
	zesty	Does not exist
linux-flo Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.4~rc8)
	vivid	Ignored (reached end-of-life)
	wily	Ignored (reached end-of-life)
	xenial	Ignored (abandoned)
	yakkety	Ignored (abandoned)
	zesty	Does not exist
linux-fsl-imx51 Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-gke Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	xenial	Not vulnerable (4.4.0-1003.3)
	yakkety	Does not exist
	zesty	Does not exist
linux-goldfish Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.4~rc8)
	vivid	Ignored (reached end-of-life)
	wily	Ignored (reached end-of-life)
	xenial	Ignored (abandoned)
	yakkety	Ignored (abandoned)
	zesty	Ignored (abandoned)
linux-grouper Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-hwe Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
	zesty	Does not exist
linux-hwe-edge Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	xenial	Not vulnerable (4.8.0-36.36~16.04.1)
	yakkety	Does not exist
	zesty	Does not exist
linux-linaro-omap Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-linaro-shared Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-linaro-vexpress Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-quantal Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [end-of-life])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-lts-raring Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [end-of-life])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-saucy Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [end-of-life])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
	This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty Launchpad, Ubuntu, Debian	precise	Released (3.13.0-79.123~precise1)
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-utopic Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was released [3.16.0-60.80~14.04.1])
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-vivid Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was released [3.19.0-51.57~14.04.1])
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-wily Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was released [4.2.0-27.32~14.04.1])
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-lts-xenial Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Not vulnerable (4.4.0-13.29~14.04.1)
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-maguro Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-mako Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.4~rc8)
	vivid	Ignored (reached end-of-life)
	wily	Ignored (reached end-of-life)
	xenial	Ignored (abandoned)
	yakkety	Ignored (abandoned)
	zesty	Does not exist
linux-manta Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist (trusty was ignored)
	upstream	Released (4.4~rc8)
	vivid	Ignored (reached end-of-life)
	wily	Ignored (reached end-of-life)
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-qcm-msm Launchpad, Ubuntu, Debian	precise	Does not exist (precise was ignored [abandoned])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist
linux-raspi2 Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Released (4.2.0-1022.29)
	xenial	Not vulnerable (4.4.0-1003.4)
	yakkety	Not vulnerable (4.4.0-1009.10)
	zesty	Not vulnerable (4.8.0-1013.15)
linux-snapdragon Launchpad, Ubuntu, Debian	precise	Does not exist
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	wily	Does not exist
	xenial	Not vulnerable (4.4.0-1012.12)
	yakkety	Not vulnerable (4.4.0-1012.12)
	zesty	Not vulnerable (4.4.0-1029.32)
linux-ti-omap4 Launchpad, Ubuntu, Debian	precise	Does not exist (precise was released [3.2.0-1477.100])
	trusty	Does not exist
	upstream	Released (4.4~rc8)
	vivid	Does not exist
	wily	Does not exist
	xenial	Does not exist
	yakkety	Does not exist
	zesty	Does not exist

Severity score breakdown

Parameter	Value
Base score	5.5
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Bugs

https://launchpad.net/bugs/1530400

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