NULL pointer dereference in Linux kernel - CVE-2020-14356

Vulnerability identifier: #VU49669

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-14356

CWE-ID: CWE-476

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a NULL pointer dereference error in the Linux kernel cgroupv2 subsystem during system reboot. A local user can crash the system or execute arbitrary code with elevated privileges.

Linux kernel
Ubuntu
linux-image-generic (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-virtual-hwe-16.04 (Ubuntu package)
linux-image-4.15.0-118-generic (Ubuntu package)
linux-image-4.15.0-118-generic-lpae (Ubuntu package)
linux-image-4.15.0-118-lowlatency (Ubuntu package)
linux-image-oem (Ubuntu package)
linux-image-generic-hwe-16.04 (Ubuntu package)
linux-image-generic-lpae-hwe-16.04 (Ubuntu package)
linux-image-lowlatency-hwe-16.04 (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-4.15.0-1054-oracle (Ubuntu package)
linux-image-oracle-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1070-gke (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-gke-4.15 (Ubuntu package)
linux-image-raspi2 (Ubuntu package)
linux-image-4.15.0-1071-raspi2 (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-4.15.0-1075-kvm (Ubuntu package)
linux-image-aws-hwe (Ubuntu package)
linux-image-aws-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1083-aws (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-4.15.0-1084-gcp (Ubuntu package)
linux-image-gcp-lts-18.04 (Ubuntu package)
linux-image-snapdragon (Ubuntu package)
linux-image-4.15.0-1087-snapdragon (Ubuntu package)
linux-image-azure-lts-18.04 (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-azure-edge (Ubuntu package)
linux-image-4.15.0-1096-azure (Ubuntu package)
linux-image-4.15.0-1097-oem (Ubuntu package)
linux-image-5.3.0-66-lowlatency (Ubuntu package)
linux-image-5.3.0-66-generic (Ubuntu package)
linux-image-gkeop-5.3 (Ubuntu package)
linux-image-raspi2-hwe-18.04 (Ubuntu package)
linux-image-5.3.0-1032-raspi2 (Ubuntu package)
linux-image-gke-5.3 (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-5.3.0-1034-gke (Ubuntu package)
linux-image-5.3.0-1034-aws (Ubuntu package)
linux-image-oem-osp1 (Ubuntu package)
linux-image-5.4.0-45-lowlatency (Ubuntu package)
linux-image-5.4.0-45-generic-lpae (Ubuntu package)
linux-image-5.4.0-45-generic (Ubuntu package)
linux-image-virtual-hwe-18.04 (Ubuntu package)
linux-image-generic-hwe-18.04 (Ubuntu package)
linux-image-generic-lpae-hwe-18.04 (Ubuntu package)
linux-image-gkeop-5.4 (Ubuntu package)
linux-image-lowlatency-hwe-18.04 (Ubuntu package)
linux-image-snapdragon-hwe-18.04 (Ubuntu package)
linux-image-5.4.0-1016-raspi (Ubuntu package)
linux-image-raspi-hwe-18.04 (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-aws-edge (Ubuntu package)
linux-image-gke-5.4 (Ubuntu package)
linux-image-5.4.0-1022-aws (Ubuntu package)
linux-image-5.4.0-1022-gcp (Ubuntu package)
linux-image-5.4.0-1022-oracle (Ubuntu package)
linux-image-5.4.0-1023-azure (Ubuntu package)

Install update from vendor's website.

Linux kernel - update to 5.7.10
linux-image-generic (Ubuntu package) - addressed in versions 4.15.0.118.105, 5.4.0.45.49
linux-image-generic-lpae (Ubuntu package) - addressed in versions 4.15.0.118.105, 5.4.0.45.49
linux-image-virtual (Ubuntu package) - addressed in versions 4.15.0.118.105, 5.4.0.45.49
linux-image-lowlatency (Ubuntu package) - addressed in versions 4.15.0.118.105, 5.4.0.45.49
linux-image-virtual-hwe-16.04 (Ubuntu package) - update to 4.15.0.118.119
linux-image-4.15.0-118-generic (Ubuntu package) - addressed in versions 4.15.0-118.119, 4.15.0-118.119~16.04.1
linux-image-4.15.0-118-generic-lpae (Ubuntu package) - addressed in versions 4.15.0-118.119, 4.15.0-118.119~16.04.1
linux-image-4.15.0-118-lowlatency (Ubuntu package) - addressed in versions 4.15.0-118.119, 4.15.0-118.119~16.04.1
linux-image-oem (Ubuntu package) - addressed in versions 4.15.0.118.119, 4.15.0.1097.101, 5.4.0.45.49
linux-image-generic-hwe-16.04 (Ubuntu package) - update to 4.15.0.118.119
linux-image-generic-lpae-hwe-16.04 (Ubuntu package) - update to 4.15.0.118.119
linux-image-lowlatency-hwe-16.04 (Ubuntu package) - update to 4.15.0.118.119
linux-image-oracle (Ubuntu package) - addressed in versions 4.15.0.1054.44, 5.4.0.1022.7, 5.4.0.1022.20
linux-image-4.15.0-1054-oracle (Ubuntu package) - addressed in versions 4.15.0-1054.58, 4.15.0-1054.58~16.04.1
linux-image-oracle-lts-18.04 (Ubuntu package) - update to 4.15.0.1054.64
linux-image-4.15.0-1070-gke (Ubuntu package) - update to 4.15.0-1070.73
linux-image-gke (Ubuntu package) - addressed in versions 4.15.0.1070.74, 4.15.0.1084.85, 5.4.0.1022.20
linux-image-gke-4.15 (Ubuntu package) - update to 4.15.0.1070.74
linux-image-raspi2 (Ubuntu package) - addressed in versions 4.15.0.1071.68, 5.4.0.1016.51
linux-image-4.15.0-1071-raspi2 (Ubuntu package) - update to 4.15.0-1071.75
linux-image-kvm (Ubuntu package) - addressed in versions 4.15.0.1075.71, 5.4.0.1021.20
linux-image-4.15.0-1075-kvm (Ubuntu package) - update to 4.15.0-1075.76
linux-image-aws-hwe (Ubuntu package) - update to 4.15.0.1083.79
linux-image-aws-lts-18.04 (Ubuntu package) - update to 4.15.0.1083.85
linux-image-4.15.0-1083-aws (Ubuntu package) - addressed in versions 4.15.0-1083.87, 4.15.0-1083.87~16.04.1
linux-image-gcp (Ubuntu package) - addressed in versions 4.15.0.1084.85, 5.4.0.1022.9, 5.4.0.1022.20
linux-image-4.15.0-1084-gcp (Ubuntu package) - addressed in versions 4.15.0-1084.95, 4.15.0-1084.95~16.04.1
linux-image-gcp-lts-18.04 (Ubuntu package) - update to 4.15.0.1084.102
linux-image-snapdragon (Ubuntu package) - update to 4.15.0.1087.90
linux-image-4.15.0-1087-snapdragon (Ubuntu package) - update to 4.15.0-1087.95
linux-image-azure-lts-18.04 (Ubuntu package) - update to 4.15.0.1096.69
linux-image-azure (Ubuntu package) - addressed in versions 4.15.0.1096.72, 4.15.0.1096.90, 5.4.0.1023.7, 5.4.0.1023.22
linux-image-azure-edge (Ubuntu package) - update to 4.15.0.1096.90
linux-image-4.15.0-1096-azure (Ubuntu package) - addressed in versions 4.15.0-1096.106, 4.15.0-1096.106~14.04.1, 4.15.0-1096.106~16.04.1
linux-image-4.15.0-1097-oem (Ubuntu package) - update to 4.15.0-1097.107
linux-image-5.3.0-66-lowlatency (Ubuntu package) - update to 5.3.0-66.60
linux-image-5.3.0-66-generic (Ubuntu package) - update to 5.3.0-66.60
linux-image-gkeop-5.3 (Ubuntu package) - update to 5.3.0.66.123
linux-image-raspi2-hwe-18.04 (Ubuntu package) - update to 5.3.0.1032.22
linux-image-5.3.0-1032-raspi2 (Ubuntu package) - update to 5.3.0-1032.34
linux-image-gke-5.3 (Ubuntu package) - update to 5.3.0.1034.19
linux-image-aws (Ubuntu package) - addressed in versions 5.3.0.1034.33, 5.4.0.1022.23
linux-image-5.3.0-1034-gke (Ubuntu package) - update to 5.3.0-1034.36
linux-image-5.3.0-1034-aws (Ubuntu package) - update to 5.3.0-1034.36
linux-image-oem-osp1 (Ubuntu package) - update to 5.4.0.45.49
linux-image-5.4.0-45-lowlatency (Ubuntu package) - update to 5.4.0-45.49~18.04.2
linux-image-5.4.0-45-generic-lpae (Ubuntu package) - update to 5.4.0-45.49~18.04.2
linux-image-5.4.0-45-generic (Ubuntu package) - update to 5.4.0-45.49~18.04.2
linux-image-virtual-hwe-18.04 (Ubuntu package) - update to 5.4.0.45.49~18.04.38
linux-image-generic-hwe-18.04 (Ubuntu package) - update to 5.4.0.45.49~18.04.38
linux-image-generic-lpae-hwe-18.04 (Ubuntu package) - update to 5.4.0.45.49~18.04.38
linux-image-gkeop-5.4 (Ubuntu package) - update to 5.4.0.45.49~18.04.38
linux-image-lowlatency-hwe-18.04 (Ubuntu package) - update to 5.4.0.45.49~18.04.38
linux-image-snapdragon-hwe-18.04 (Ubuntu package) - update to 5.4.0.45.49~18.04.38
linux-image-5.4.0-1016-raspi (Ubuntu package) - update to 5.4.0-1016.17~18.04.1
linux-image-raspi-hwe-18.04 (Ubuntu package) - update to 5.4.0.1016.20
linux-image-raspi (Ubuntu package) - update to 5.4.0.1016.51
linux-image-aws-edge (Ubuntu package) - update to 5.4.0.1022.8
linux-image-gke-5.4 (Ubuntu package) - update to 5.4.0.1022.9
linux-image-5.4.0-1022-aws (Ubuntu package) - update to 5.4.0-1022.22~18.04.1
linux-image-5.4.0-1022-gcp (Ubuntu package) - update to 5.4.0-1022.22~18.04.1
linux-image-5.4.0-1022-oracle (Ubuntu package) - update to 5.4.0-1022.22~18.04.1
linux-image-5.4.0-1023-azure (Ubuntu package) - update to 5.4.0-1023.23~18.04.1

• http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00047.html
• http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00007.html
• https://bugzilla.kernel.org/show_bug.cgi?id=208003
• https://bugzilla.redhat.com/show_bug.cgi?id=1868453
• https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html
• https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
• https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
• https://lore.kernel.org/netdev/CAM_iQpUKQJrj8wE+Qa8NGR3P0L+5Uz=qo-O5+k_P60HzTde6aw%40mail.gmail.com/t/
• https://security.netapp.com/advisory/ntap-20200904-0002/
• https://usn.ubuntu.com/4483-1/
• https://usn.ubuntu.com/4484-1/
• https://usn.ubuntu.com/4526-1/

• Privilege escalation in Linux kernel
• Ubuntu update for linux-aws-5.3
• Ubuntu update for linux
• Ubuntu update for linux