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

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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