CVE-2018-20669

An issue where a provided address with access_ok() is not checked was discovered in i915_gem_execbuffer2_ioctl in drivers/gpu/drm/i915/i915_gem_execbuffer.c in the Linux kernel through 4.19.13. A local attacker can craft a malicious IOCTL function call to overwrite arbitrary kernel memory, resulting in a Denial of Service or privilege escalation.

From the Ubuntu Security Team

Timothy Michaud discovered that the i915 graphics driver in the Linux kernel did not properly validate user memory locations for the i915_gem_execbuffer2_ioctl. A local attacker could possibly use this to cause a denial of service or execute arbitrary code.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
linux	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 4.15.0-115.116
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
linux-aws	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 4.15.0-1080.84
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
linux-aws-5.0	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-aws-5.3	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-aws-5.4	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-aws-hwe	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Fixed 4.15.0-1080.84~16.04.1
	14.04 LTS trusty	Not in release
linux-azure	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 5.0.0-1014.14~18.04.1
	16.04 LTS xenial	Fixed 4.15.0-1093.103~16.04.1
	14.04 LTS trusty	Fixed 4.15.0-1093.103~14.04.1 Ubuntu Pro
linux-azure-4.15	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Fixed 4.15.0-1093.103
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-azure-5.3	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-azure-5.4	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-azure-edge	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Fixed 5.0.0-1014.14~18.04.1
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-euclid	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-flo	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-gcp	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 5.0.0-1020.20~18.04.1
	16.04 LTS xenial	Fixed 4.15.0-1081.92~16.04.1
	14.04 LTS trusty	Not in release
linux-gcp-4.15	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Fixed 4.15.0-1081.92
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-gcp-5.3	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-gcp-5.4	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-gcp-edge	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Fixed 5.0.0-1020.20~18.04.1
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-gke	20.04 LTS focal	Not affected
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-gke-4.15	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.04 LTS bionic	Fixed 4.15.0-1067.70
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-gke-5.0	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-gke-5.3	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-goldfish	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-grouper	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-hwe	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Fixed 5.0.0-23.24~18.04.1
	16.04 LTS xenial	Fixed 4.15.0-115.116~16.04.1
	14.04 LTS trusty	Not in release
linux-hwe-5.4	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-hwe-edge	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-kvm	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 4.15.0-1072.73
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
linux-lts-trusty	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-lts-utopic	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored
linux-lts-vivid	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored
linux-lts-wily	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored
linux-lts-xenial	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not affected
linux-maguro	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-mako	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-manta	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.10 cosmic	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-oem	20.04 LTS focal	Not in release
	19.10 eoan	Ignored
	19.04 disco	Ignored
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 4.15.0-1094.104
	16.04 LTS xenial	Ignored
	14.04 LTS trusty	Not in release
linux-oem-5.6	20.04 LTS focal	Not affected
	19.10 eoan	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-oem-osp1	20.04 LTS focal	Not in release
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-oracle	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Fixed 5.0.0-1004.8
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 4.15.0-1051.55
	16.04 LTS xenial	Fixed 4.15.0-1051.55~16.04.1
	14.04 LTS trusty	Not in release
linux-oracle-5.0	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-oracle-5.3	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-oracle-5.4	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-raspi	20.04 LTS focal	Not affected
	19.10 eoan	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-raspi-5.4	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-raspi2	20.04 LTS focal	Not affected
	19.10 eoan	Not affected
	19.04 disco	Not affected
	18.10 cosmic	Ignored
	18.04 LTS bionic	Fixed 4.15.0-1068.72
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
linux-raspi2-5.3	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-riscv	20.04 LTS focal	Not affected
	19.10 eoan	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
linux-snapdragon	20.04 LTS focal	Not in release
	19.10 eoan	Not in release
	19.04 disco	Not affected
	18.10 cosmic	Not in release
	18.04 LTS bionic	Fixed 4.15.0-1084.92
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release

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Notes

tyhicks

Only the i915_gem_execbuffer2_ioctl() changes are technically needed for this CVE. It would be ideal to audit the callers of the other changed functions in the fix commit. This CVE is being disputed. See the oss-security emails on 2019-02-07 for details.

sbeattie

while this specific ioctl may or may not be vulnerable, the fix is generic aenough to possibly block other vulnerabilities.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
linux	Introduced by 2889caa, fixed by 594cc25

Severity score breakdown

Parameter	Value
Base score	7.8 · High
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

USN-4485-1
Linux kernel vulnerabilities
3 September 2020