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6.7
Android Kernel: Improper Locking Allows Local Privilege Escalation
UBUNTU-CVE-2021-39656
Summary
An issue has been found in the Android kernel, which could allow an attacker with local access to gain elevated system privileges. This could potentially allow the attacker to access sensitive system data or take control of the device. Android kernel users should update their kernel to the latest version to address this issue.
What to do
- Update canonical linux-azure to version 4.15.0-1115.128~14.04.1.
- Update canonical linux-aws-hwe to version 4.15.0-1103.110~16.04.1.
- Update canonical linux-azure to version 4.15.0-1115.128~16.04.1.
- Update canonical linux-gcp to version 4.15.0-1100.113~16.04.1.
- Update canonical linux-hwe to version 4.15.0-144.148~16.04.1.
- Update canonical linux-oracle to version 4.15.0-1072.80~16.04.1.
- Update canonical linux to version 4.15.0-144.148.
- Update canonical linux-aws to version 4.15.0-1103.110.
- Update canonical linux-aws-5.4 to version 5.4.0-1048.50~18.04.1.
- Update canonical linux-azure-4.15 to version 4.15.0-1115.128.
- Update canonical linux-azure-5.4 to version 5.4.0-1047.49~18.04.1.
- Update canonical linux-dell300x to version 4.15.0-1022.26.
- Update canonical linux-gcp-4.15 to version 4.15.0-1100.113.
- Update canonical linux-gcp-5.4 to version 5.4.0-1043.46~18.04.1.
- Update canonical linux-gke-5.4 to version 5.4.0-1043.45~18.04.1.
- Update canonical linux-gkeop-5.4 to version 5.4.0-1015.16~18.04.1.
- Update canonical linux-hwe-5.4 to version 5.4.0-73.82~18.04.1.
- Update canonical linux-kvm to version 4.15.0-1092.94.
- Update canonical linux-oracle to version 4.15.0-1072.80.
- Update canonical linux-oracle-5.4 to version 5.4.0-1044.47~18.04.1.
- Update canonical linux-raspi-5.4 to version 5.4.0-1035.38~18.04.1.
- Update canonical linux-raspi2 to version 4.15.0-1086.91.
- Update canonical linux-snapdragon to version 4.15.0-1103.112.
- Update canonical linux-aws-fips to version 4.15.0-2045.47.
- Update canonical linux-azure-fips to version 4.15.0-2027.30.
- Update canonical linux-fips to version 4.15.0-1060.68.
- Update canonical linux to version 5.4.0-73.82.
- Update canonical linux-aws to version 5.4.0-1048.50.
- Update canonical linux-azure to version 5.4.0-1047.49.
- Update canonical linux-gcp to version 5.4.0-1043.46.
- Update canonical linux-gke to version 5.4.0-1043.45.
- Update canonical linux-gkeop to version 5.4.0-1015.16.
- Update canonical linux-kvm to version 5.4.0-1039.40.
- Update canonical linux-oem-5.10 to version 5.10.0-1021.22.
- Update canonical linux-oracle to version 5.4.0-1045.49.
- Update canonical linux-raspi to version 5.4.0-1035.38.
- Update canonical linux-aws-fips to version 5.4.0-1069.73+fips2.
- Update canonical linux-azure-fips to version 5.4.0-1073.76+fips1.
- Update canonical linux-gcp-fips to version 5.4.0-1067.71~20.04.1.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| Ubuntu:Pro:14.04:LTS | canonical | linux-azure |
< 4.15.0-1115.128~14.04.1 Fix: upgrade to 4.15.0-1115.128~14.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-aws-hwe |
< 4.15.0-1103.110~16.04.1 Fix: upgrade to 4.15.0-1103.110~16.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-azure |
< 4.15.0-1115.128~16.04.1 Fix: upgrade to 4.15.0-1115.128~16.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-gcp |
< 4.15.0-1100.113~16.04.1 Fix: upgrade to 4.15.0-1100.113~16.04.1
|
| Ubuntu:Pro:16.04:LTS | canonical | linux-hwe |
< 4.15.0-144.148~16.04.1 Fix: upgrade to 4.15.0-144.148~16.04.1
|
| Ubuntu:16.04:LTS | canonical | linux-hwe-edge | All versions |
| Ubuntu:Pro:16.04:LTS | canonical | linux-oracle |
< 4.15.0-1072.80~16.04.1 Fix: upgrade to 4.15.0-1072.80~16.04.1
|
| Ubuntu:18.04:LTS | canonical | linux |
< 4.15.0-144.148 Fix: upgrade to 4.15.0-144.148
|
| Ubuntu:18.04:LTS | canonical | linux-aws |
< 4.15.0-1103.110 Fix: upgrade to 4.15.0-1103.110
|
| Ubuntu:18.04:LTS | canonical | linux-aws-5.4 |
< 5.4.0-1048.50~18.04.1 Fix: upgrade to 5.4.0-1048.50~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-azure-4.15 |
< 4.15.0-1115.128 Fix: upgrade to 4.15.0-1115.128
|
| Ubuntu:18.04:LTS | canonical | linux-azure-5.4 |
< 5.4.0-1047.49~18.04.1 Fix: upgrade to 5.4.0-1047.49~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-dell300x |
< 4.15.0-1022.26 Fix: upgrade to 4.15.0-1022.26
|
| Ubuntu:18.04:LTS | canonical | linux-gcp-4.15 |
< 4.15.0-1100.113 Fix: upgrade to 4.15.0-1100.113
|
| Ubuntu:18.04:LTS | canonical | linux-gcp-5.4 |
< 5.4.0-1043.46~18.04.1 Fix: upgrade to 5.4.0-1043.46~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-gke-5.4 |
< 5.4.0-1043.45~18.04.1 Fix: upgrade to 5.4.0-1043.45~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-gkeop-5.4 |
< 5.4.0-1015.16~18.04.1 Fix: upgrade to 5.4.0-1015.16~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-hwe-5.4 |
< 5.4.0-73.82~18.04.1 Fix: upgrade to 5.4.0-73.82~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-kvm |
< 4.15.0-1092.94 Fix: upgrade to 4.15.0-1092.94
|
| Ubuntu:18.04:LTS | canonical | linux-oracle |
< 4.15.0-1072.80 Fix: upgrade to 4.15.0-1072.80
|
| Ubuntu:18.04:LTS | canonical | linux-oracle-5.4 |
< 5.4.0-1044.47~18.04.1 Fix: upgrade to 5.4.0-1044.47~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-raspi-5.4 |
< 5.4.0-1035.38~18.04.1 Fix: upgrade to 5.4.0-1035.38~18.04.1
|
| Ubuntu:18.04:LTS | canonical | linux-raspi2 |
< 4.15.0-1086.91 Fix: upgrade to 4.15.0-1086.91
|
| Ubuntu:18.04:LTS | canonical | linux-snapdragon |
< 4.15.0-1103.112 Fix: upgrade to 4.15.0-1103.112
|
| Ubuntu:18.04:LTS | canonical | linux-aws-5.0 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-aws-5.3 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-azure | All versions |
| Ubuntu:18.04:LTS | canonical | linux-azure-5.3 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-azure-edge | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gcp | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gcp-5.3 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-gke-4.15 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-hwe | All versions |
| Ubuntu:18.04:LTS | canonical | linux-hwe-edge | All versions |
| Ubuntu:18.04:LTS | canonical | linux-oem | All versions |
| Ubuntu:18.04:LTS | canonical | linux-oracle-5.0 | All versions |
| Ubuntu:18.04:LTS | canonical | linux-oracle-5.3 | All versions |
| Ubuntu:Pro:FIPS-updates:18.04:LTS | canonical | linux-aws-fips |
< 4.15.0-2045.47 Fix: upgrade to 4.15.0-2045.47
|
| Ubuntu:Pro:FIPS-updates:18.04:LTS | canonical | linux-azure-fips |
< 4.15.0-2027.30 Fix: upgrade to 4.15.0-2027.30
|
| Ubuntu:Pro:FIPS-updates:18.04:LTS | canonical | linux-fips |
< 4.15.0-1060.68 Fix: upgrade to 4.15.0-1060.68
|
| Ubuntu:Pro:FIPS:18.04:LTS | canonical | linux-fips | All versions |
| Ubuntu:20.04:LTS | canonical | linux |
< 5.4.0-73.82 Fix: upgrade to 5.4.0-73.82
|
| Ubuntu:20.04:LTS | canonical | linux-aws |
< 5.4.0-1048.50 Fix: upgrade to 5.4.0-1048.50
|
| Ubuntu:20.04:LTS | canonical | linux-azure |
< 5.4.0-1047.49 Fix: upgrade to 5.4.0-1047.49
|
| Ubuntu:20.04:LTS | canonical | linux-gcp |
< 5.4.0-1043.46 Fix: upgrade to 5.4.0-1043.46
|
| Ubuntu:20.04:LTS | canonical | linux-gke |
< 5.4.0-1043.45 Fix: upgrade to 5.4.0-1043.45
|
| Ubuntu:20.04:LTS | canonical | linux-gkeop |
< 5.4.0-1015.16 Fix: upgrade to 5.4.0-1015.16
|
| Ubuntu:20.04:LTS | canonical | linux-kvm |
< 5.4.0-1039.40 Fix: upgrade to 5.4.0-1039.40
|
| Ubuntu:20.04:LTS | canonical | linux-oem-5.10 |
< 5.10.0-1021.22 Fix: upgrade to 5.10.0-1021.22
|
| Ubuntu:20.04:LTS | canonical | linux-oracle |
< 5.4.0-1045.49 Fix: upgrade to 5.4.0-1045.49
|
| Ubuntu:20.04:LTS | canonical | linux-raspi |
< 5.4.0-1035.38 Fix: upgrade to 5.4.0-1035.38
|
| Ubuntu:20.04:LTS | canonical | linux-aws-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-azure-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-gcp-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-hwe-5.11 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-hwe-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-intel-5.13 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oem-5.6 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-oracle-5.8 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-raspi2 | All versions |
| Ubuntu:20.04:LTS | canonical | linux-riscv | All versions |
| Ubuntu:20.04:LTS | canonical | linux-riscv-5.8 | All versions |
| Ubuntu:Pro:FIPS-updates:20.04:LTS | canonical | linux-aws-fips |
< 5.4.0-1069.73+fips2 Fix: upgrade to 5.4.0-1069.73+fips2
|
| Ubuntu:Pro:FIPS-updates:20.04:LTS | canonical | linux-azure-fips |
< 5.4.0-1073.76+fips1 Fix: upgrade to 5.4.0-1073.76+fips1
|
| Ubuntu:Pro:FIPS-updates:20.04:LTS | canonical | linux-gcp-fips |
< 5.4.0-1067.71~20.04.1 Fix: upgrade to 5.4.0-1067.71~20.04.1
|
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-aws-fips | All versions |
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-azure-fips | All versions |
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-fips | All versions |
| Ubuntu:Pro:FIPS:20.04:LTS | canonical | linux-gcp-fips | All versions |
| Ubuntu:22.04:LTS | canonical | linux-intel-iot-realtime | All versions |
| Ubuntu:22.04:LTS | canonical | linux-realtime | All versions |
| Ubuntu:24.04:LTS | canonical | linux-raspi-realtime | All versions |
| Ubuntu:26.04 | canonical | linux-nvidia | All versions |
Original title
In __configfs_open_file of file.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with System execution privileges needed...
Original description
In __configfs_open_file of file.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-174049066References: Upstream kernel
osv CVSS3.1
6.7
- https://ubuntu.com/security/CVE-2021-39656 Third Party Advisory
- https://source.android.com/security/bulletin/pixel/2021-12-01 Third Party Advisory
- https://git.kernel.org/linus/14fbbc8297728e880070f7b077b3301a8c698ef9 Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2021-39656 Third Party Advisory
Published: 15 Dec 2021 · Updated: 12 May 2026 · First seen: 12 May 2026