Improper locking in Linux kernel - CVE-2020-29660

Vulnerability identifier: #VU57039

CSH Severity: Low

CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-29660

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to double-locking error in drivers/tty/tty_io.c and drivers/tty/tty_jobctrl.c. An authenticated local user can exploit this vulnerability to perform a read-after-free attack against TIOCGSID and gain access to sensitive information.

Linux kernel
Amazon Linux AMI
Anolis OS
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
Google Android
Ubuntu
openEuler
Fedora
linux-image-server (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-3.13.0-188-lowlatency (Ubuntu package)
linux-image-3.13.0-188-generic (Ubuntu package)
linux-image-powerpc-e500mc-lts-xenial (Ubuntu package)
linux-image-generic-lpae-lts-xenial (Ubuntu package)
linux-image-generic-lts-xenial (Ubuntu package)
linux-image-lowlatency-lts-xenial (Ubuntu package)
linux-image-powerpc-smp-lts-xenial (Ubuntu package)
linux-image-powerpc64-emb-lts-xenial (Ubuntu package)
linux-image-powerpc64-smp-lts-xenial (Ubuntu package)
linux-image-virtual-lts-xenial (Ubuntu package)
linux-image-powerpc64-smp (Ubuntu package)
linux-image-powerpc64-emb (Ubuntu package)
linux-image-powerpc-smp (Ubuntu package)
linux-image-powerpc-e500mc (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-4.4.0-203-generic (Ubuntu package)
linux-image-4.4.0-203-powerpc64-smp (Ubuntu package)
linux-image-4.4.0-203-powerpc64-emb (Ubuntu package)
linux-image-4.4.0-203-powerpc-smp (Ubuntu package)
linux-image-4.4.0-203-generic-lpae (Ubuntu package)
linux-image-4.4.0-203-lowlatency (Ubuntu package)
linux-image-4.4.0-203-powerpc-e500mc (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-4.4.0-1086-aws (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-4.4.0-1088-kvm (Ubuntu package)
linux-image-4.4.0-1122-aws (Ubuntu package)
linux-image-raspi2 (Ubuntu package)
linux-image-4.4.0-1146-raspi2 (Ubuntu package)
linux-image-snapdragon (Ubuntu package)
linux-image-4.4.0-1150-snapdragon (Ubuntu package)
kernel
linux-image-generic-hwe-16.04 (Ubuntu package)
linux-image-virtual-hwe-16.04 (Ubuntu package)
linux-image-oem (Ubuntu package)
linux-image-lowlatency-hwe-16.04 (Ubuntu package)
linux-image-generic-lpae-hwe-16.04 (Ubuntu package)
linux-image-4.15.0-136-generic-lpae (Ubuntu package)
linux-image-4.15.0-136-generic (Ubuntu package)
linux-image-4.15.0-136-lowlatency (Ubuntu package)
linux-image-dell300x (Ubuntu package)
linux-image-4.15.0-1012-dell300x (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-4.15.0-1065-oracle (Ubuntu package)
linux-image-oracle-lts-18.04 (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-gke-4.15 (Ubuntu package)
linux-image-4.15.0-1079-gke (Ubuntu package)
linux-image-4.15.0-1079-raspi2 (Ubuntu package)
linux-image-4.15.0-1085-kvm (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-4.15.0-1093-gcp (Ubuntu package)
linux-image-gcp-lts-18.04 (Ubuntu package)
linux-image-aws-hwe (Ubuntu package)
linux-image-aws-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1094-aws (Ubuntu package)
linux-image-4.15.0-1096-snapdragon (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-azure-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1108-azure (Ubuntu package)
kernel (Red Hat package)
kernel-rt (Red Hat package)
bpftool
python3-perf-debuginfo
python3-perf
python2-perf-debuginfo
python2-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
python-perf
kernel-debug
kernel-debug-devel
kernel-headers
kernel-tools-libs
kernel-tools-libs-devel
linux-image-oem-osp1 (Ubuntu package)
linux-image-5.4.0-66-generic (Ubuntu package)
linux-image-5.4.0-66-lowlatency (Ubuntu package)
linux-image-5.4.0-66-generic-lpae (Ubuntu package)
linux-image-generic-hwe-18.04 (Ubuntu package)
linux-image-generic-lpae-hwe-18.04 (Ubuntu package)
linux-image-lowlatency-hwe-18.04 (Ubuntu package)
linux-image-snapdragon-hwe-18.04 (Ubuntu package)
linux-image-virtual-hwe-18.04 (Ubuntu package)
linux-image-5.4.0-1010-gkeop (Ubuntu package)
linux-image-gkeop-5.4 (Ubuntu package)
linux-image-gkeop (Ubuntu package)
linux-image-5.4.0-1029-raspi (Ubuntu package)
linux-image-raspi-hwe-18.04 (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-5.4.0-1033-kvm (Ubuntu package)
linux-image-5.4.0-1036-gke (Ubuntu package)
linux-image-gke-5.4 (Ubuntu package)
linux-image-5.4.0-1037-gcp (Ubuntu package)
linux-image-5.4.0-1038-aws (Ubuntu package)
linux-image-5.4.0-1038-oracle (Ubuntu package)
linux-image-5.4.0-1040-azure (Ubuntu package)
linux-image-oem-20.04 (Ubuntu package)
linux-image-5.6.0-1048-oem (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-5.8.0-44-generic-64k (Ubuntu package)
linux-image-5.8.0-44-generic (Ubuntu package)
linux-image-5.8.0-44-generic-lpae (Ubuntu package)
linux-image-5.8.0-44-lowlatency (Ubuntu package)
linux-image-generic-64k-hwe-20.04 (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-lowlatency-hwe-20.04 (Ubuntu package)
linux-image-generic-lpae-hwe-20.04 (Ubuntu package)
linux-image-generic-hwe-20.04 (Ubuntu package)
linux-image-5.8.0-1016-raspi (Ubuntu package)
linux-image-5.8.0-1016-raspi-nolpae (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1019-kvm (Ubuntu package)
linux-image-5.8.0-1021-oracle (Ubuntu package)
linux-image-5.8.0-1023-gcp (Ubuntu package)
linux-image-5.8.0-1023-azure (Ubuntu package)
linux-image-5.8.0-1024-aws (Ubuntu package)

Install updates from vendor's website.

Linux kernel - update to 5.9.14
Google Android - addressed in versions 8.1 2021-10-05, 9 2021-10-05, 10 2021-10-05, 11 2021-10-05
linux-image-server (Ubuntu package) - update to 3.13.0188.239
linux-image-lowlatency (Ubuntu package) - addressed in versions 3.13.0188.239, 4.4.0.203.209, 4.15.0.136.123, 5.4.0.66.69, 5.8.0.44.49
linux-image-virtual (Ubuntu package) - addressed in versions 3.13.0188.239, 4.4.0.203.209, 4.15.0.136.123, 5.4.0.66.69, 5.8.0.44.49
linux-image-generic (Ubuntu package) - addressed in versions 3.13.0188.239, 4.4.0.203.209, 4.15.0.136.123, 5.4.0.66.69, 5.8.0.44.49
linux-image-3.13.0-188-lowlatency (Ubuntu package) - update to 3.13.0188.239
linux-image-3.13.0-188-generic (Ubuntu package) - update to 3.13.0188.239
linux-image-powerpc-e500mc-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-generic-lpae-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-generic-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-lowlatency-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-powerpc-smp-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-powerpc64-emb-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-powerpc64-smp-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-virtual-lts-xenial (Ubuntu package) - update to 4.4.0.203.177
linux-image-powerpc64-smp (Ubuntu package) - update to 4.4.0.203.209
linux-image-powerpc64-emb (Ubuntu package) - update to 4.4.0.203.209
linux-image-powerpc-smp (Ubuntu package) - update to 4.4.0.203.209
linux-image-powerpc-e500mc (Ubuntu package) - update to 4.4.0.203.209
linux-image-generic-lpae (Ubuntu package) - addressed in versions 4.4.0.203.209, 4.15.0.136.123, 5.4.0.66.69, 5.8.0.44.49
linux-image-4.4.0-203-generic (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-4.4.0-203-powerpc64-smp (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-4.4.0-203-powerpc64-emb (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-4.4.0-203-powerpc-smp (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-4.4.0-203-generic-lpae (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-4.4.0-203-lowlatency (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-4.4.0-203-powerpc-e500mc (Ubuntu package) - addressed in versions 4.4.0-203.235, 4.4.0-203.235~14.04.1
linux-image-aws (Ubuntu package) - addressed in versions 4.4.0.1086.83, 4.4.0.1122.127, 5.4.0.1038.22, 5.4.0.1038.39, 5.8.0.1024.26
linux-image-4.4.0-1086-aws (Ubuntu package) - update to 4.4.0-1086.90
linux-image-kvm (Ubuntu package) - addressed in versions 4.4.0.1088.86, 4.15.0.1085.81, 5.4.0.1033.31, 5.8.0.1019.21
linux-image-4.4.0-1088-kvm (Ubuntu package) - update to 4.4.0-1088.97
linux-image-4.4.0-1122-aws (Ubuntu package) - update to 4.4.0-1122.136
linux-image-raspi2 (Ubuntu package) - addressed in versions 4.4.0.1146.146, 4.15.0.1079.76, 5.4.0.1029.64
linux-image-4.4.0-1146-raspi2 (Ubuntu package) - update to 4.4.0-1146.156
linux-image-snapdragon (Ubuntu package) - addressed in versions 4.4.0.1150.142, 4.15.0.1096.99
linux-image-4.4.0-1150-snapdragon (Ubuntu package) - update to 4.4.0-1150.160
kernel - update to 4.14.214-118.339
linux-image-generic-hwe-16.04 (Ubuntu package) - update to 4.15.0.136.132
linux-image-virtual-hwe-16.04 (Ubuntu package) - update to 4.15.0.136.132
linux-image-oem (Ubuntu package) - addressed in versions 4.15.0.136.132, 5.4.0.66.69, 5.4.0.66.74~18.04.61
linux-image-lowlatency-hwe-16.04 (Ubuntu package) - update to 4.15.0.136.132
linux-image-generic-lpae-hwe-16.04 (Ubuntu package) - update to 4.15.0.136.132
linux-image-4.15.0-136-generic-lpae (Ubuntu package) - update to 4.15.0-136.140~16.04.1
linux-image-4.15.0-136-generic (Ubuntu package) - update to 4.15.0-136.140~16.04.1
linux-image-4.15.0-136-lowlatency (Ubuntu package) - update to 4.15.0-136.140~16.04.1
linux-image-dell300x (Ubuntu package) - update to 4.15.0.1012.14
linux-image-4.15.0-1012-dell300x (Ubuntu package) - update to 4.15.0-1012.16
linux-image-oracle (Ubuntu package) - addressed in versions 4.15.0.1065.53, 5.4.0.1038.35, 5.4.0.1038.41~18.04.21, 5.8.0.1021.20
linux-image-4.15.0-1065-oracle (Ubuntu package) - update to 4.15.0-1065.73~16.04.1
linux-image-oracle-lts-18.04 (Ubuntu package) - update to 4.15.0.1065.75
linux-image-gke (Ubuntu package) - addressed in versions 4.15.0.1079.83, 4.15.0.1093.94, 5.8.0.1023.23
linux-image-gke-4.15 (Ubuntu package) - update to 4.15.0.1079.83
linux-image-4.15.0-1079-gke (Ubuntu package) - update to 4.15.0-1079.84
linux-image-4.15.0-1079-raspi2 (Ubuntu package) - update to 4.15.0-1079.84
linux-image-4.15.0-1085-kvm (Ubuntu package) - update to 4.15.0-1085.87
linux-image-gcp (Ubuntu package) - addressed in versions 4.15.0.1093.94, 5.4.0.1037.24, 5.4.0.1037.46, 5.8.0.1023.23
linux-image-4.15.0-1093-gcp (Ubuntu package) - update to 4.15.0-1093.106~16.04.1
linux-image-gcp-lts-18.04 (Ubuntu package) - update to 4.15.0.1093.111
linux-image-aws-hwe (Ubuntu package) - update to 4.15.0.1094.87
linux-image-aws-lts-18.04 (Ubuntu package) - update to 4.15.0.1094.97
linux-image-4.15.0-1094-aws (Ubuntu package) - update to 4.15.0-1094.101~16.04.1
linux-image-4.15.0-1096-snapdragon (Ubuntu package) - update to 4.15.0-1096.105
linux-image-azure (Ubuntu package) - addressed in versions 4.15.0.1108.81, 4.15.0.1108.99, 5.4.0.1040.20, 5.4.0.1040.38, 5.8.0.1023.23
linux-image-azure-lts-18.04 (Ubuntu package) - update to 4.15.0.1108.81
linux-image-4.15.0-1108-azure (Ubuntu package) - addressed in versions 4.15.0-1108.120~14.04.1, 4.15.0-1108.120~16.04.1
kernel (Red Hat package) - update to 4.18.0-348.el8
kernel-rt (Red Hat package) - update to 4.18.0-348.rt7.130.el8
bpftool - update to 4.19.90-2101.1.0.0055
python3-perf-debuginfo - update to 4.19.90-2101.1.0.0055
python3-perf - update to 4.19.90-2101.1.0.0055
python2-perf-debuginfo - update to 4.19.90-2101.1.0.0055
python2-perf - update to 4.19.90-2101.1.0.0055
perf-debuginfo - update to 4.19.90-2101.1.0.0055
perf - update to 4.19.90-2101.1.0.0055
kernel-tools-devel - update to 4.19.90-2101.1.0.0055
kernel-tools-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-tools - update to 4.19.90-2101.1.0.0055
kernel-source - update to 4.19.90-2101.1.0.0055
kernel-devel - update to 4.19.90-2101.1.0.0055
kernel-debugsource - update to 4.19.90-2101.1.0.0055
kernel-debuginfo - update to 4.19.90-2101.1.0.0055
bpftool-debuginfo - update to 4.19.90-2101.1.0.0055
kernel - update to 4.19.90-2101.1.0.0055
kernel - update to 4.19.91-26
bpftool - update to 4.19.91-26
python-perf - update to 4.19.91-26
kernel-debug - update to 4.19.91-26
kernel-debug-devel - update to 4.19.91-26
kernel-devel - update to 4.19.91-26
kernel-headers - update to 4.19.91-26
kernel-tools - update to 4.19.91-26
kernel-tools-libs - update to 4.19.91-26
perf - update to 4.19.91-26
kernel-tools-libs-devel - update to 4.19.91-26
linux-image-oem-osp1 (Ubuntu package) - addressed in versions 5.4.0.66.69, 5.4.0.66.74~18.04.61
linux-image-5.4.0-66-generic (Ubuntu package) - addressed in versions 5.4.0-66.74, 5.4.0-66.74~18.04.2
linux-image-5.4.0-66-lowlatency (Ubuntu package) - addressed in versions 5.4.0-66.74, 5.4.0-66.74~18.04.2
linux-image-5.4.0-66-generic-lpae (Ubuntu package) - addressed in versions 5.4.0-66.74, 5.4.0-66.74~18.04.2
linux-image-generic-hwe-18.04 (Ubuntu package) - update to 5.4.0.66.74~18.04.61
linux-image-generic-lpae-hwe-18.04 (Ubuntu package) - update to 5.4.0.66.74~18.04.61
linux-image-lowlatency-hwe-18.04 (Ubuntu package) - update to 5.4.0.66.74~18.04.61
linux-image-snapdragon-hwe-18.04 (Ubuntu package) - update to 5.4.0.66.74~18.04.61
linux-image-virtual-hwe-18.04 (Ubuntu package) - update to 5.4.0.66.74~18.04.61
linux-image-5.4.0-1010-gkeop (Ubuntu package) - addressed in versions 5.4.0-1010.11, 5.4.0-1010.11~18.04.1
linux-image-gkeop-5.4 (Ubuntu package) - addressed in versions 5.4.0.1010.11~18.04.11, 5.4.0.1010.13
linux-image-gkeop (Ubuntu package) - update to 5.4.0.1010.13
linux-image-5.4.0-1029-raspi (Ubuntu package) - addressed in versions 5.4.0-1029.32, 5.4.0-1029.32~18.04.1
linux-image-raspi-hwe-18.04 (Ubuntu package) - update to 5.4.0.1029.32
linux-image-raspi (Ubuntu package) - addressed in versions 5.4.0.1029.64, 5.8.0.1016.19
linux-image-5.4.0-1033-kvm (Ubuntu package) - update to 5.4.0-1033.34
linux-image-5.4.0-1036-gke (Ubuntu package) - update to 5.4.0-1036.38~18.04.1
linux-image-gke-5.4 (Ubuntu package) - update to 5.4.0.1036.38~18.04.4
linux-image-5.4.0-1037-gcp (Ubuntu package) - addressed in versions 5.4.0-1037.40, 5.4.0-1037.40~18.04.1
linux-image-5.4.0-1038-aws (Ubuntu package) - addressed in versions 5.4.0-1038.40, 5.4.0-1038.40~18.04.1
linux-image-5.4.0-1038-oracle (Ubuntu package) - addressed in versions 5.4.0-1038.41, 5.4.0-1038.41~18.04.1
linux-image-5.4.0-1040-azure (Ubuntu package) - addressed in versions 5.4.0-1040.42, 5.4.0-1040.42~18.04.1
linux-image-oem-20.04 (Ubuntu package) - addressed in versions 5.6.0.1048.44, 5.8.0.44.49
linux-image-5.6.0-1048-oem (Ubuntu package) - update to 5.6.0-1048.52
linux-image-generic-64k (Ubuntu package) - update to 5.8.0.44.49
linux-image-5.8.0-44-generic-64k (Ubuntu package) - update to 5.8.0-44.50
linux-image-5.8.0-44-generic (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-5.8.0-44-generic-lpae (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-5.8.0-44-lowlatency (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-5.8.0-1016-raspi (Ubuntu package) - update to 5.8.0-1016.19
linux-image-5.8.0-1016-raspi-nolpae (Ubuntu package) - update to 5.8.0-1016.19
linux-image-raspi-nolpae (Ubuntu package) - update to 5.8.0.1016.19
linux-image-5.8.0-1019-kvm (Ubuntu package) - update to 5.8.0-1019.21
linux-image-5.8.0-1021-oracle (Ubuntu package) - update to 5.8.0-1021.22
linux-image-5.8.0-1023-gcp (Ubuntu package) - update to 5.8.0-1023.24
linux-image-5.8.0-1023-azure (Ubuntu package) - update to 5.8.0-1023.25
linux-image-5.8.0-1024-aws (Ubuntu package) - update to 5.8.0-1024.26
kernel - addressed in versions 5.9.14-100.fc32, 5.9.14-200.fc33

• http://www.openwall.com/lists/oss-security/2020/12/10/1
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c8bcd9c5be24fb9e6132e97da5a35e55a83e36b9
• https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html
• https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BOB25SU6XUL4TNP7KB63WNZSYTIYFDPP/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MZ7OAKAEFAXQRGBZK4LYUWINCD3D2XCL/
• https://security.netapp.com/advisory/ntap-20210122-0001/
• https://www.debian.org/security/2021/dsa-4843

• Information disclosure in Linux kernel
• Multiple vulnerabilities in Google Android
• Ubuntu update for linux
• Ubuntu update for linux
• Amazon Linux AMI update for kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8 update for kernel
• Ubuntu update for linux-oem-5.6
• Ubuntu update for linux
• Ubuntu update for linux
• Ubuntu update for linux
• openEuler update for kernel
• Anolis OS update for kernel(ANCK)4.19
• Fedora 33 update for kernel
• Fedora 32 update for kernel