CVE-2018-1092

Published: 1 April 2018

The ext4_iget function in fs/ext4/inode.c in the Linux kernel through 4.15.15 mishandles the case of a root directory with a zero i_links_count, which allows attackers to cause a denial of service (ext4_process_freed_data NULL pointer dereference and OOPS) via a crafted ext4 image.

From the Ubuntu Security Team

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly handle corrupted meta data in some situations. An attacker could use this to specially craft an ext4 filesystem that caused a denial of service (system crash) when mounted.

Priority

Cvss 3 Severity Score

5.5

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Released (4.15.0-23.25)
	trusty	Released (3.13.0-157.207)
	xenial	Released (4.4.0-128.154)
	artful	Released (4.13.0-45.50)
	cosmic	Not vulnerable (4.15.0-23.25)
	Patches: Introduced by 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Fixed by 8e4b5eae5decd9dfe5a4ee369c22028f90ab4c44
linux-flo Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Does not exist
	trusty	Does not exist (trusty was ignored [abandoned])
	xenial	Ignored (abandoned)
	artful	Does not exist
	cosmic	Does not exist
linux-aws Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Released (4.15.0-1010.10)
	trusty	Released (4.4.0-1023.23)
	artful	Does not exist
	cosmic	Not vulnerable (4.15.0-1010.10)
	xenial	Released (4.4.0-1061.70)
linux-azure Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Released (4.15.0-1013.13)
	artful	Does not exist
	cosmic	Not vulnerable (4.15.0-1013.13)
	trusty	Not vulnerable (4.15.0-1023.24~14.04.1)
	xenial	Released (4.15.0-1013.13~16.04.2)
linux-gcp Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Released (4.15.0-1009.9)
	artful	Does not exist
	cosmic	Not vulnerable (4.15.0-1009.9)
	trusty	Does not exist
	xenial	Released (4.13.0-1019.23)
linux-euclid Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	trusty	Does not exist
	xenial	Ignored (was needs-triage ESM criteria)
linux-azure-edge Launchpad, Ubuntu, Debian	upstream	Released (4.17~rc1)
	bionic	Not vulnerable (4.18.0-1003.3~18.04.1)
	cosmic	Does not exist
	trusty	Does not exist
	xenial	Released (4.15.0-1013.13)
linux-lts-trusty Launchpad, Ubuntu, Debian	trusty	Does not exist
	xenial	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-goldfish Launchpad, Ubuntu, Debian	trusty	Does not exist (trusty was ignored [abandoned])
	xenial	Ignored (end of life, was needed)
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-grouper Launchpad, Ubuntu, Debian	trusty	Does not exist (trusty was ignored [abandoned])
	xenial	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-lts-utopic Launchpad, Ubuntu, Debian	trusty	Does not exist (trusty was ignored [end of standard support])
	xenial	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-lts-vivid Launchpad, Ubuntu, Debian	trusty	Does not exist (trusty was ignored [end of standard support])
	xenial	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-lts-wily Launchpad, Ubuntu, Debian	trusty	Does not exist (trusty was ignored [end of standard support])
	xenial	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-lts-xenial Launchpad, Ubuntu, Debian	trusty	Released (4.4.0-128.154~14.04.1)
	xenial	Does not exist
	artful	Does not exist
	cosmic	Does not exist
	bionic	Does not exist
	upstream	Released (4.17~rc1)
linux-snapdragon Launchpad, Ubuntu, Debian	trusty	Does not exist
	xenial	Released (4.4.0-1094.99)
	artful	Released (4.4.0-1094.99)
	cosmic	Does not exist
	bionic	Not vulnerable
	upstream	Released (4.17~rc1)
linux-gke Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Does not exist
	cosmic	Does not exist
	trusty	Does not exist
	upstream	Released (4.17~rc1)
	xenial	Ignored (end of standard support, was needed)
linux-hwe Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Not vulnerable
	cosmic	Does not exist
	trusty	Does not exist
	upstream	Released (4.17~rc1)
	xenial	Released (4.13.0-45.50~16.04.1)
linux-hwe-edge Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Not vulnerable (4.18.0-8.9~18.04.1)
	cosmic	Does not exist
	trusty	Does not exist
	upstream	Released (4.17~rc1)
	xenial	Released (4.13.0-45.50~16.04.1)
linux-kvm Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Released (4.15.0-1011.11)
	cosmic	Not vulnerable (4.15.0-1011.11)
	trusty	Does not exist
	upstream	Released (4.17~rc1)
	xenial	Released (4.4.0-1027.32)
linux-maguro Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Does not exist
	cosmic	Does not exist
	trusty	Does not exist (trusty was ignored [abandoned])
	upstream	Released (4.17~rc1)
	xenial	Does not exist
linux-mako Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Does not exist
	cosmic	Does not exist
	trusty	Does not exist (trusty was ignored [abandoned])
	upstream	Released (4.17~rc1)
	xenial	Ignored (abandoned)
linux-manta Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Does not exist
	cosmic	Does not exist
	trusty	Does not exist (trusty was ignored [abandoned])
	upstream	Released (4.17~rc1)
	xenial	Does not exist
linux-oem Launchpad, Ubuntu, Debian	artful	Does not exist
	bionic	Released (4.15.0-1008.11)
	cosmic	Not vulnerable (4.15.0-1008.11)
	trusty	Does not exist
	upstream	Released (4.17~rc1)
	xenial	Released (4.13.0-1030.33)
linux-raspi2 Launchpad, Ubuntu, Debian	artful	Released (4.13.0-1022.23)
	bionic	Released (4.15.0-1012.13)
	cosmic	Not vulnerable (4.15.0-1021.23)
	trusty	Does not exist
	upstream	Released (4.17~rc1)
	xenial	Released (4.4.0-1091.99)

Severity score breakdown

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

References

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