CVE-2014-8086

Published: 13 October 2014

Race condition in the ext4_file_write_iter function in fs/ext4/file.c in the Linux kernel through 3.17 allows local users to cause a denial of service (file unavailability) via a combination of a write action and an F_SETFL fcntl operation for the O_DIRECT flag.

From the Ubuntu security team

Dmitry Monakhov discovered a race condition in the ext4_file_write_iter function of the Linux kernel's ext4 filesystem. A local user could exploit this flaw to cause a denial of service (file unavailability).

Priority

Medium

CVSS 3 base score: 4.7

Status

Package Release Status
linux
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Not vulnerable

Patches:
Introduced by 8ad2850f44831919f63f0e58d7203e65d5b3914c
Fixed by a41537e69b4aa43f0fea02498c2595a81267383b
linux-2.6
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-armadaxp
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

This package is not directly supported by the Ubuntu Security Team
linux-ec2
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-flo
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-fsl-imx51
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-goldfish
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-grouper
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-linaro-omap
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-linaro-shared
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-linaro-vexpress
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-quantal
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

This package is not directly supported by the Ubuntu Security Team
linux-lts-raring
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-saucy
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

This package is not directly supported by the Ubuntu Security Team
linux-lts-trusty
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-lts-utopic
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was released [3.16.0-26.35~14.04.1])
linux-lts-vivid
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was not-affected [3.19.0-18.18~14.04.1])
linux-maguro
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-mako
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-manta
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist
(trusty was ignored)
linux-mvl-dove
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-qcm-msm
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-raspi2
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

linux-ti-omap4
Launchpad, Ubuntu, Debian
Upstream
Released (3.18~rc3)
Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Notes

AuthorNote
jdstrand
android kernels (flo, goldfish, grouper, maguro, mako and manta) are
not supported on the Ubuntu Touch 14.04 preview kernels
linux-lts-saucy no longer receives official support
linux-lts-quantal no longer receives official support
apw
looks like the end if the discussion above on the ext4 list points to
changes proposed in https://lkml.org/lkml/2014/10/18/63, unsure if they
are sufficient either.
this was applied with a different subject line

References

Bugs