CVE-2021-47254: gfs2: Fix use-after-free in gfs2_glock_shrink_scan

Published May 21, 2024
·
Updated

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

gfs2: Fix use-after-free in gfs2glockshrinkscan

The GLFLRU flag is checked under lrulock in gfs2glockremovefromlru() to remove the glock from the lru list in gfs2glockput().

On the shrink scan path, the same flag is cleared under lrulock but because of condreschedlock(&lrulock) in gfs2disposeglocklru(), progress on the put side can be made without deleting the glock from the lru list.

Keep GLFLRU across the race window opened by condreschedlock(&lrulock) to ensure correct behavior on both sides - clear GLFLRU after listdel under lrulock.

Affected Software

126 affected componentsFixes available
Linux Linux kernel>=4.4.181<4.4.274
Linux Linux kernel>=4.9.180<4.9.274
Linux Linux kernel>=4.14.123<4.14.238
Linux Linux kernel>=4.19.47<4.19.196
Linux Linux kernel>=5.0.20<5.1
Linux Linux kernel>=5.1.6<5.4.127
Linux Linux kernel>=5.5<5.10.45
Linux Linux kernel>=5.11<5.12.12
Linux Linux kernel=5.13-rc1
Linux Linux kernel=5.13-rc2
Linux Linux kernel=5.13-rc3
Linux Linux kernel=5.13-rc4
ubuntu/linux-azure<4.15.0-1123.136~14.04.1
4.15.0-1123.136~14.04.1
ubuntu/linux-aws<4.4.0-1153.159
4.4.0-1153.159
ubuntu/linux-lts-xenial<4.4.0-279.313~14.04.1
4.4.0-279.313~14.04.1
ubuntu/linux<4.4.0-279.313
4.4.0-279.313
ubuntu/linux-aws<4.4.0-1191.206
4.4.0-1191.206
ubuntu/linux-aws-hwe<4.15.0-1111.118~16.04.1
4.15.0-1111.118~16.04.1
ubuntu/linux-azure<4.15.0-1123.136~16.04.1
4.15.0-1123.136~16.04.1
ubuntu/linux-gcp<4.15.0-1108.122~16.04.1
4.15.0-1108.122~16.04.1
ubuntu/linux-hwe<4.15.0-156.163~16.04.1
4.15.0-156.163~16.04.1
ubuntu/linux-kvm<4.4.0-1154.165
4.4.0-1154.165
ubuntu/linux-oracle<4.15.0-1080.88~16.04.1
4.15.0-1080.88~16.04.1
ubuntu/linux-hwe-edge*
ubuntu/linux-fips<4.4.0-1123.130
4.4.0-1123.130
ubuntu/linux-fips*
ubuntu/linux<4.15.0-156.163
4.15.0-156.163
ubuntu/linux-aws<4.15.0-1111.118
4.15.0-1111.118
ubuntu/linux-aws-5.4<5.4.0-1055.58~18.04.1
5.4.0-1055.58~18.04.1
ubuntu/linux-azure-4.15<4.15.0-1123.136
4.15.0-1123.136
ubuntu/linux-azure-5.4<5.4.0-1056.58~18.04.1
5.4.0-1056.58~18.04.1
ubuntu/linux-gcp-4.15<4.15.0-1108.122
4.15.0-1108.122
ubuntu/linux-gcp-5.4<5.4.0-1051.55~18.04.1
5.4.0-1051.55~18.04.1
ubuntu/linux-hwe-5.4<5.4.0-81.91~18.04.1
5.4.0-81.91~18.04.1
ubuntu/linux-kvm<4.15.0-1099.101
4.15.0-1099.101
ubuntu/linux-oracle<4.15.0-1080.88
4.15.0-1080.88
ubuntu/linux-oracle-5.4<5.4.0-1053.57~18.04.1
5.4.0-1053.57~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1042.46~18.04.3
5.4.0-1042.46~18.04.3
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<4.15.0-2053.55
4.15.0-2053.55
ubuntu/linux-azure-fips<4.15.0-2035.39
4.15.0-2035.39
ubuntu/linux-fips<4.15.0-1069.78
4.15.0-1069.78
ubuntu/linux-gcp-fips<4.15.0-2018.20
4.15.0-2018.20
ubuntu/linux-fips*
ubuntu/linux<5.4.0-81.91
5.4.0-81.91
ubuntu/linux-aws<5.4.0-1055.58
5.4.0-1055.58
ubuntu/linux-azure<5.4.0-1056.58
5.4.0-1056.58
ubuntu/linux-bluefield<5.4.0-1019.22
5.4.0-1019.22
ubuntu/linux-gcp<5.4.0-1051.55
5.4.0-1051.55
ubuntu/linux-gkeop<5.4.0-1022.23
5.4.0-1022.23
ubuntu/linux-kvm<5.4.0-1045.47
5.4.0-1045.47
ubuntu/linux-oracle<5.4.0-1053.57
5.4.0-1053.57
ubuntu/linux-raspi<5.4.0-1042.46
5.4.0-1042.46
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<5.4.0-1032.37
5.4.0-1032.37
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.

  1. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.15.0-1123.136~14.04.1
  2. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 4.4.0-1153.159
  3. Upgrade

    Upgrade ubuntu/linux-lts-xenial to a version that resolves this vulnerability.

    Fixed in 4.4.0-279.313~14.04.1
  4. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 4.4.0-279.313
  5. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 4.4.0-1191.206
  6. Upgrade

    Upgrade ubuntu/linux-aws-hwe to a version that resolves this vulnerability.

    Fixed in 4.15.0-1111.118~16.04.1
  7. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.15.0-1123.136~16.04.1
  8. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 4.15.0-1108.122~16.04.1
  9. Upgrade

    Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.

    Fixed in 4.15.0-156.163~16.04.1
  10. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 4.4.0-1154.165
  11. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 4.15.0-1080.88~16.04.1
  12. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 4.4.0-1123.130
  13. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 4.15.0-156.163
  14. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 4.15.0-1111.118
  15. Upgrade

    Upgrade ubuntu/linux-aws-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1055.58~18.04.1
  16. Upgrade

    Upgrade ubuntu/linux-azure-4.15 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1123.136
  17. Upgrade

    Upgrade ubuntu/linux-azure-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1056.58~18.04.1
  18. Upgrade

    Upgrade ubuntu/linux-gcp-4.15 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1108.122
  19. Upgrade

    Upgrade ubuntu/linux-gcp-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1051.55~18.04.1
  20. Upgrade

    Upgrade ubuntu/linux-hwe-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-81.91~18.04.1
  21. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 4.15.0-1099.101
  22. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 4.15.0-1080.88
  23. Upgrade

    Upgrade ubuntu/linux-oracle-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1053.57~18.04.1
  24. Upgrade

    Upgrade ubuntu/linux-raspi-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1042.46~18.04.3
  25. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2053.55
  26. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2035.39
  27. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-1069.78
  28. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 4.15.0-2018.20
  29. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 5.4.0-81.91
  30. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 5.4.0-1055.58
  31. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.4.0-1056.58
  32. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 5.4.0-1019.22
  33. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.4.0-1051.55
  34. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 5.4.0-1022.23
  35. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 5.4.0-1045.47
  36. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 5.4.0-1053.57
  37. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 5.4.0-1042.46
  38. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 5.4.0-1069.73+fips2
  39. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 5.4.0-1073.76+fips1
  40. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 5.4.0-1032.37
  41. 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

May 21, 2024
CVE Published
via MITRE·02:19 PM
Data Sourced
via MITRE·02:19 PM
DescriptionSeverity
Data Sourced
via OSV·03:15 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·03:15 PM
RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2021-47254?

CVE-2021-47254 has not been assigned a specific CVSS score, but it is categorized as a use-after-free vulnerability in the Linux kernel.

2

How do I fix CVE-2021-47254?

To fix CVE-2021-47254, you should upgrade to a patched version of the Linux kernel that addresses this vulnerability.

3

Which versions of the Linux kernel are affected by CVE-2021-47254?

CVE-2021-47254 affects several Linux kernel versions, specifically those below 5.13-rc4.

4

What type of vulnerability is CVE-2021-47254?

CVE-2021-47254 is classified as a use-after-free vulnerability in the GFS2 file system of the Linux kernel.

5

Is CVE-2021-47254 exploitable remotely?

The details regarding the exploitability of CVE-2021-47254 have not been disclosed, so potential remote exploitation is unclear.

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