CVE-2021-46966: ACPI: custom_method: fix potential use-after-free issue

Q: What is the severity of CVE-2021-46966?

CVE-2021-46966 has a severity rating that indicates a medium impact vulnerability in the Linux kernel.

Q: How do I fix CVE-2021-46966?

To fix CVE-2021-46966, upgrade to the patched versions of the Linux kernel, specifically versions 5.10.223-1, 5.10.226-1, 6.1.123-1, or later.

Q: What systems are affected by CVE-2021-46966?

CVE-2021-46966 affects a variety of Linux kernel versions between 4.4.195 and 5.12.3.

Q: What type of vulnerability is CVE-2021-46966?

CVE-2021-46966 is classified as a use-after-free vulnerability within the Linux kernel.

Q: Is there a workaround for CVE-2021-46966?

There is no recommended workaround for CVE-2021-46966; patching the system is the recommended mitigation.

Published Feb 27, 2024

Updated

In the Linux kernel, the following vulnerability has been resolved:

ACPI: custommethod: fix potential use-after-free issue

In cmwrite(), buf is always freed when reaching the end of the function. If the requested count is less than table.length, the allocated buffer will be freed but subsequent calls to cmwrite() will still try to access it.

Remove the unconditional kfree(buf) at the end of the function and set the buf to NULL in the -EINVAL error path to match the rest of function.

Affected Software

122 affected componentsFixes available

Linux Linux kernel>=4.4.195<4.4.269

Linux Linux kernel>=4.9.195<4.9.269

Linux Linux kernel>=4.14.147<4.14.233

Linux Linux kernel>=4.19.77<4.19.191

Linux Linux kernel>=5.4<5.4.118

Linux Linux kernel>=5.5<5.10.36

Linux Linux kernel>=5.11<5.11.20

Linux Linux kernel>=5.12<5.12.3

debian/linux

5.10.223-15.10.234-16.1.129-16.1.135-16.12.22-16.12.25-1

ubuntu/linux-aws<4.4.0-1130.136

4.4.0-1130.136

ubuntu/linux-azure<4.15.0-1121.134~14.04.1

4.15.0-1121.134~14.04.1

ubuntu/linux-lts-xenial<4.4.0-253.287~14.04.1

4.4.0-253.287~14.04.1

ubuntu/linux<4.4.0-253.287

4.4.0-253.287

ubuntu/linux-aws<4.4.0-1168.183

4.4.0-1168.183

ubuntu/linux-aws-hwe<4.15.0-1109.116~16.04.1

4.15.0-1109.116~16.04.1

ubuntu/linux-azure<4.15.0-1121.134~16.04.1

4.15.0-1121.134~16.04.1

ubuntu/linux-gcp<4.15.0-1106.120~16.04.1

4.15.0-1106.120~16.04.1

ubuntu/linux-hwe<4.15.0-151.157~16.04.1

4.15.0-151.157~16.04.1

ubuntu/linux-kvm<4.4.0-1131.141

4.4.0-1131.141

ubuntu/linux-oracle<4.15.0-1078.86~16.04.1

4.15.0-1078.86~16.04.1

ubuntu/linux-hwe-edge*

ubuntu/linux-fips<4.4.0-1100.107

4.4.0-1100.107

ubuntu/linux<4.15.0-151.157

4.15.0-151.157

ubuntu/linux-aws<4.15.0-1109.116

4.15.0-1109.116

ubuntu/linux-aws-5.4<5.4.0-1051.53~18.04.1

5.4.0-1051.53~18.04.1

ubuntu/linux-azure-4.15<4.15.0-1121.134

4.15.0-1121.134

ubuntu/linux-azure-5.4<5.4.0-1051.53~18.04.1

5.4.0-1051.53~18.04.1

ubuntu/linux-gcp-4.15<4.15.0-1106.120

4.15.0-1106.120

ubuntu/linux-gcp-5.4<5.4.0-1046.49~18.04.1

5.4.0-1046.49~18.04.1

ubuntu/linux-hwe-5.4<5.4.0-77.86~18.04.1

5.4.0-77.86~18.04.1

ubuntu/linux-kvm<4.15.0-1097.99

4.15.0-1097.99

ubuntu/linux-oracle<4.15.0-1078.86

4.15.0-1078.86

ubuntu/linux-oracle-5.4<5.4.0-1048.52~18.04.1

5.4.0-1048.52~18.04.1

ubuntu/linux-raspi-5.4<5.4.0-1038.41~18.04.1

5.4.0-1038.41~18.04.1

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-fips<4.15.0-2051.53

4.15.0-2051.53

ubuntu/linux-azure-fips<4.15.0-2033.37

4.15.0-2033.37

ubuntu/linux-fips<4.15.0-1066.75

4.15.0-1066.75

ubuntu/linux-gcp-fips<4.15.0-2016.18

4.15.0-2016.18

ubuntu/linux-fips*

ubuntu/linux<5.4.0-77.86

5.4.0-77.86

ubuntu/linux-aws<5.4.0-1051.53

5.4.0-1051.53

ubuntu/linux-azure<5.4.0-1051.53

5.4.0-1051.53

ubuntu/linux-bluefield<5.4.0-1013.16

5.4.0-1013.16

ubuntu/linux-gcp<5.4.0-1046.49

5.4.0-1046.49

ubuntu/linux-gkeop<5.4.0-1018.19

5.4.0-1018.19

ubuntu/linux-kvm<5.4.0-1041.42

5.4.0-1041.42

ubuntu/linux-oracle<5.4.0-1048.52

5.4.0-1048.52

ubuntu/linux-raspi<5.4.0-1038.41

5.4.0-1038.41

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.8*

ubuntu/linux-intel-5.13*

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.8*

ubuntu/linux-aws-fips<5.4.0-1069.73+fips2

5.4.0-1069.73+fips2

ubuntu/linux-azure-fips<5.4.0-1073.76+fips1

5.4.0-1073.76+fips1

ubuntu/linux-fips<5.4.0-1028.32

5.4.0-1028.32

ubuntu/linux-gcp-fips<5.4.0-1067.71~20.04.1

5.4.0-1067.71~20.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-nvidia-6.2*

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-raspi-realtime*

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.22-1Fixed in 6.12.25-1
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 4.4.0-1130.136
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 4.15.0-1121.134~14.04.1
Upgrade
Upgrade ubuntu/linux-lts-xenial to a version that resolves this vulnerability.
Fixed in 4.4.0-253.287~14.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 4.4.0-253.287
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 4.4.0-1168.183
Upgrade
Upgrade ubuntu/linux-aws-hwe to a version that resolves this vulnerability.
Fixed in 4.15.0-1109.116~16.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 4.15.0-1121.134~16.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 4.15.0-1106.120~16.04.1
Upgrade
Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.
Fixed in 4.15.0-151.157~16.04.1
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 4.4.0-1131.141
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 4.15.0-1078.86~16.04.1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 4.4.0-1100.107
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 4.15.0-151.157
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 4.15.0-1109.116
Upgrade
Upgrade ubuntu/linux-aws-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1051.53~18.04.1
Upgrade
Upgrade ubuntu/linux-azure-4.15 to a version that resolves this vulnerability.
Fixed in 4.15.0-1121.134
Upgrade
Upgrade ubuntu/linux-azure-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1051.53~18.04.1
Upgrade
Upgrade ubuntu/linux-gcp-4.15 to a version that resolves this vulnerability.
Fixed in 4.15.0-1106.120
Upgrade
Upgrade ubuntu/linux-gcp-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1046.49~18.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-77.86~18.04.1
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 4.15.0-1097.99
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 4.15.0-1078.86
Upgrade
Upgrade ubuntu/linux-oracle-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1048.52~18.04.1
Upgrade
Upgrade ubuntu/linux-raspi-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1038.41~18.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2051.53
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2033.37
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-1066.75
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2016.18
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.4.0-77.86
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.4.0-1051.53
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.4.0-1051.53
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.4.0-1013.16
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.4.0-1046.49
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.4.0-1018.19
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.4.0-1041.42
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.4.0-1048.52
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.4.0-1038.41
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1069.73+fips2
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1073.76+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1028.32
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1067.71~20.04.1

Event History

Feb 27, 2024

CVE Published

via MITRE·06:47 PM

Data Sourced

via MITRE·06:47 PM

Description

Data Sourced

via OSV·07:04 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

What is the severity of CVE-2021-46966?

CVE-2021-46966 has a severity rating that indicates a medium impact vulnerability in the Linux kernel.

How do I fix CVE-2021-46966?