CVE-2021-47294: netrom: Decrease sock refcount when sock timers expire

Published May 21, 2024
·
Updated

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

netrom: Decrease sock refcount when sock timers expire

Commit 63346650c1a9 ("netrom: switch to sock timer API") switched to use sock timer API. It replaces modtimer() by skresettimer(), and deltimer() by skstoptimer().

Function skresettimer() will increase the refcount of sock if it is called on an inactive timer, hence, in case the timer expires, we need to decrease the refcount ourselves in the handler, otherwise, the sock refcount will be unbalanced and the sock will never be freed.

Affected Software

126 affected componentsFixes available
Linux Linux kernel
Linux Linux kernel>=4.4.173<4.4.277
Linux Linux kernel>=4.9.155<4.9.277
Linux Linux kernel>=4.14.98<4.14.241
Linux Linux kernel>=4.19.20<4.19.199
Linux Linux kernel>=5.0<5.4.136
Linux Linux kernel>=5.5<5.10.54
Linux Linux kernel>=5.11<5.13.6
Linux Linux kernel=3.18.134
Linux Linux kernel=4.20.7
Linux Linux kernel=5.14-rc1
Linux Linux kernel=5.14-rc2
ubuntu/linux-azure<4.15.0-1124.137~14.04.1
4.15.0-1124.137~14.04.1
ubuntu/linux-aws<4.4.0-1149.155
4.4.0-1149.155
ubuntu/linux-lts-xenial<4.4.0-274.308~14.04.1
4.4.0-274.308~14.04.1
ubuntu/linux<4.4.0-274.308
4.4.0-274.308
ubuntu/linux-aws<4.4.0-1187.202
4.4.0-1187.202
ubuntu/linux-aws-hwe<4.15.0-1112.119~16.04.1
4.15.0-1112.119~16.04.1
ubuntu/linux-azure<4.15.0-1124.137~16.04.1
4.15.0-1124.137~16.04.1
ubuntu/linux-gcp<4.15.0-1109.123~16.04.1
4.15.0-1109.123~16.04.1
ubuntu/linux-hwe<4.15.0-159.167~16.04.1
4.15.0-159.167~16.04.1
ubuntu/linux-kvm<4.4.0-1150.161
4.4.0-1150.161
ubuntu/linux-oracle<4.15.0-1081.89~16.04.1
4.15.0-1081.89~16.04.1
ubuntu/linux-hwe-edge*
ubuntu/linux-fips<4.4.0-1119.126
4.4.0-1119.126
ubuntu/linux-fips*
ubuntu/linux<4.15.0-159.167
4.15.0-159.167
ubuntu/linux-aws<4.15.0-1112.119
4.15.0-1112.119
ubuntu/linux-aws-5.4<5.4.0-1057.60~18.04.1
5.4.0-1057.60~18.04.1
ubuntu/linux-azure-4.15<4.15.0-1124.137
4.15.0-1124.137
ubuntu/linux-azure-5.4<5.4.0-1059.62~18.04.1
5.4.0-1059.62~18.04.1
ubuntu/linux-gcp-4.15<4.15.0-1109.123
4.15.0-1109.123
ubuntu/linux-gcp-5.4<5.4.0-1053.57~18.04.1
5.4.0-1053.57~18.04.1
ubuntu/linux-hwe-5.4<5.4.0-87.98~18.04.1
5.4.0-87.98~18.04.1
ubuntu/linux-kvm<4.15.0-1100.102
4.15.0-1100.102
ubuntu/linux-oracle<4.15.0-1081.89
4.15.0-1081.89
ubuntu/linux-oracle-5.4<5.4.0-1055.59~18.04.1
5.4.0-1055.59~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1044.48~18.04.1
5.4.0-1044.48~18.04.1
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<4.15.0-2054.56
4.15.0-2054.56
ubuntu/linux-azure-fips<4.15.0-2036.40
4.15.0-2036.40
ubuntu/linux-fips<4.15.0-1070.79
4.15.0-1070.79
ubuntu/linux-gcp-fips<4.15.0-2019.21
4.15.0-2019.21
ubuntu/linux-fips*
ubuntu/linux<5.4.0-88.99
5.4.0-88.99
ubuntu/linux-aws<5.4.0-1057.60
5.4.0-1057.60
ubuntu/linux-azure<5.4.0-1059.62
5.4.0-1059.62
ubuntu/linux-bluefield<5.4.0-1019.22
5.4.0-1019.22
ubuntu/linux-gcp<5.4.0-1053.57
5.4.0-1053.57
ubuntu/linux-gkeop<5.4.0-1024.25
5.4.0-1024.25
ubuntu/linux-ibm<5.4.0-1005.6
5.4.0-1005.6
ubuntu/linux-kvm<5.4.0-1047.49
5.4.0-1047.49
ubuntu/linux-oracle<5.4.0-1055.59
5.4.0-1055.59
ubuntu/linux-raspi<5.4.0-1044.48
5.4.0-1044.48
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<5.4.0-1034.40
5.4.0-1034.40
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*

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 4.15.0-1124.137~14.04.1
  2. Upgrade

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

    Fixed in 4.4.0-1149.155
  3. Upgrade

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

    Fixed in 4.4.0-274.308~14.04.1
  4. Upgrade

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

    Fixed in 4.4.0-274.308
  5. Upgrade

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

    Fixed in 4.4.0-1187.202
  6. Upgrade

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

    Fixed in 4.15.0-1112.119~16.04.1
  7. Upgrade

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

    Fixed in 4.15.0-1124.137~16.04.1
  8. Upgrade

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

    Fixed in 4.15.0-1109.123~16.04.1
  9. Upgrade

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

    Fixed in 4.15.0-159.167~16.04.1
  10. Upgrade

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

    Fixed in 4.4.0-1150.161
  11. Upgrade

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

    Fixed in 4.15.0-1081.89~16.04.1
  12. Upgrade

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

    Fixed in 4.4.0-1119.126
  13. Upgrade

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

    Fixed in 4.15.0-159.167
  14. Upgrade

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

    Fixed in 4.15.0-1112.119
  15. Upgrade

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

    Fixed in 5.4.0-1057.60~18.04.1
  16. Upgrade

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

    Fixed in 4.15.0-1124.137
  17. Upgrade

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

    Fixed in 5.4.0-1059.62~18.04.1
  18. Upgrade

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

    Fixed in 4.15.0-1109.123
  19. Upgrade

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

    Fixed in 5.4.0-1053.57~18.04.1
  20. Upgrade

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

    Fixed in 5.4.0-87.98~18.04.1
  21. Upgrade

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

    Fixed in 4.15.0-1100.102
  22. Upgrade

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

    Fixed in 4.15.0-1081.89
  23. Upgrade

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

    Fixed in 5.4.0-1055.59~18.04.1
  24. Upgrade

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

    Fixed in 5.4.0-1044.48~18.04.1
  25. Upgrade

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

    Fixed in 4.15.0-2054.56
  26. Upgrade

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

    Fixed in 4.15.0-2036.40
  27. Upgrade

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

    Fixed in 4.15.0-1070.79
  28. Upgrade

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

    Fixed in 4.15.0-2019.21
  29. Upgrade

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

    Fixed in 5.4.0-88.99
  30. Upgrade

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

    Fixed in 5.4.0-1057.60
  31. Upgrade

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

    Fixed in 5.4.0-1059.62
  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 5.4.0-1053.57
  34. Upgrade

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

    Fixed in 5.4.0-1024.25
  35. Upgrade

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

    Fixed in 5.4.0-1005.6
  36. Upgrade

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

    Fixed in 5.4.0-1047.49
  37. Upgrade

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

    Fixed in 5.4.0-1055.59
  38. Upgrade

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

    Fixed in 5.4.0-1044.48
  39. Upgrade

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

    Fixed in 5.4.0-1069.73+fips2
  40. Upgrade

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

    Fixed in 5.4.0-1073.76+fips1
  41. Upgrade

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

    Fixed in 5.4.0-1034.40
  42. Upgrade

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

    Fixed in 5.4.0-1067.71~20.04.1
  43. Compensating control

    In the netrom socket timer expiration handler, explicitly decrease the socket reference count when a timer expires after using sk_reset_timer(), so the sock refcount remains balanced and the socket can be freed.

Event History

May 21, 2024
CVE Published
via MITRE·02:35 PM
Data Sourced
via MITRE·02:35 PM
Description
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-2021-47294?

CVE-2021-47294 has a severity rating of medium, indicating potential risk to system integrity.

2

How do I fix CVE-2021-47294?

To resolve CVE-2021-47294, update your Linux kernel to a version that is not affected by this vulnerability.

3

What versions of the Linux kernel are affected by CVE-2021-47294?

CVE-2021-47294 affects Linux kernel versions between 3.18.134 and 5.14-rc2.

4

What is the nature of the vulnerability in CVE-2021-47294?

CVE-2021-47294 concerns an issue with decreased socket reference counts when socket timers expire.

5

Is there a patch available for CVE-2021-47294?

Yes, patches have been released as part of newer Linux kernel updates that resolve CVE-2021-47294.

Company

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