CVE-2020-8992

Published: 14 February 2020

ext4_protect_reserved_inode in fs/ext4/block_validity.c in the Linux kernel through 5.5.3 allows attackers to cause a denial of service (soft lockup) via a crafted journal size.

From the Ubuntu Security Team

Shijie Luo discovered that the ext4 file system implementation in the Linux kernel did not properly check for a too-large journal size. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (soft lockup).

Priority

Cvss 3 Severity Score

5.5

Score breakdown

Status

Package	Release	Status
linux Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-96.97)
	eoan	Released (5.3.0-51.44)
	focal	Not vulnerable (5.4.0-18.22)
	trusty	Ignored (was needs-triage ESM criteria)
	upstream	Released (5.6~rc2)
	xenial	Released (4.4.0-185.215)
	Patches: Introduced by 345c0dbf3a30872d9b204db96b5857cd00808cae Fixed by af133ade9a40794a37104ecbcc2827c0ea373a3c
linux-aws Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1065.69)
	eoan	Released (5.3.0-1017.18)
	focal	Not vulnerable (5.4.0-1005.5)
	trusty	Released (4.4.0-1074.78) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.6~rc2)
	xenial	Released (4.4.0-1110.121)
linux-aws-5.0 Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needed)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-aws-5.3 Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-1017.18~18.04.1)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-aws-hwe Launchpad, Ubuntu, Debian	bionic	Does not exist
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.15.0-1065.69~16.04.1)
linux-azure Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needed)
	eoan	Released (5.3.0-1020.21)
	focal	Not vulnerable (5.4.0-1006.6)
	trusty	Released (4.15.0-1077.82~14.04.1) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.6~rc2)
	xenial	Released (4.15.0-1077.82)
linux-azure-4.15 Launchpad, Ubuntu, Debian	bionic	Not vulnerable (4.15.0-1082.92)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-azure-5.3 Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-1020.21~18.04.1)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-azure-edge Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needs-triage)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-gcp Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needed)
	eoan	Released (5.3.0-1018.19)
	focal	Not vulnerable (5.4.0-1005.5)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.15.0-1060.64)
linux-gcp-4.15 Launchpad, Ubuntu, Debian	bionic	Not vulnerable (4.15.0-1071.81)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-gcp-5.3 Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-1018.19~18.04.1)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-gcp-edge Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needs-triage)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-gke-4.15 Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1057.60)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-gke-5.0 Launchpad, Ubuntu, Debian	bionic	Released (5.0.0-1035.36)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-gke-5.3 Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-1018.19~18.04.1)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-hwe Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-51.44~18.04.2)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.15.0-96.97~16.04.1)
linux-hwe-edge Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needs-triage)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Ignored (end of life, was needs-triage)
linux-kvm Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1058.59)
	eoan	Released (5.3.0-1016.17)
	focal	Not vulnerable (5.4.0-1004.4)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.4.0-1076.83)
linux-lts-trusty Launchpad, Ubuntu, Debian	bionic	Does not exist
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-lts-xenial Launchpad, Ubuntu, Debian	bionic	Does not exist
	eoan	Does not exist
	focal	Does not exist
	trusty	Released (4.4.0-185.215~14.04.1) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-oem Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1079.89)
	eoan	Released (4.15.0-1079.89)
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Ignored (end of standard support, was needs-triage)
linux-oem-5.6 Launchpad, Ubuntu, Debian	bionic	Does not exist
	eoan	Does not exist
	focal	Not vulnerable (5.6.0-1007.7)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-oem-osp1 Launchpad, Ubuntu, Debian	bionic	Released (5.0.0-1050.55)
	eoan	Ignored (end of life, was pending)
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-oracle Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1037.41)
	eoan	Released (5.3.0-1016.18)
	focal	Not vulnerable (5.4.0-1005.5)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.15.0-1037.41~16.04.1)
linux-oracle-5.0 Launchpad, Ubuntu, Debian	bionic	Ignored (end of life, was needed)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-oracle-5.3 Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-1016.18~18.04.1)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-raspi Launchpad, Ubuntu, Debian	bionic	Does not exist
	eoan	Does not exist
	focal	Not vulnerable (5.4.0-1007.7)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-raspi2 Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1060.64)
	eoan	Released (5.3.0-1023.25)
	focal	Ignored (end of life, was needs-triage)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.4.0-1135.144)
linux-raspi2-5.3 Launchpad, Ubuntu, Debian	bionic	Released (5.3.0-1023.25~18.04.1)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-riscv Launchpad, Ubuntu, Debian	bionic	Does not exist
	eoan	Does not exist
	focal	Not vulnerable (5.4.0-24.28)
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Does not exist
linux-snapdragon Launchpad, Ubuntu, Debian	bionic	Released (4.15.0-1076.83)
	eoan	Does not exist
	focal	Does not exist
	trusty	Does not exist
	upstream	Released (5.6~rc2)
	xenial	Released (4.4.0-1139.147)

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:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Join the discussion

Canonical is offering Expanded Security Maintenance

Canonical is offering Ubuntu Expanded Security Maintenance (ESM) for security fixes and essential packages.

Find out more about ESM ›