UBUNTU-CVE-2021-28714: High severity ubuntu/linux-azure vulnerability

Published Jan 6, 2022
·
Updated

Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default). Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time. (CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. (CVE-2021-28714)

Affected Software

99 affected componentsFixes available
ubuntu/linux-azure<4.15.0-1131.144~14.04.1
4.15.0-1131.144~14.04.1
ubuntu/linux-aws<4.4.0-1161.167
4.4.0-1161.167
ubuntu/linux-lts-xenial<4.4.0-290.324~14.04.1
4.4.0-290.324~14.04.1
ubuntu/linux-aws-hwe<4.15.0-1120.128~16.04.1
4.15.0-1120.128~16.04.1
ubuntu/linux-azure<4.15.0-1131.144~16.04.1
4.15.0-1131.144~16.04.1
ubuntu/linux-gcp<4.15.0-1116.130~16.04.1
4.15.0-1116.130~16.04.1
ubuntu/linux-hwe<4.15.0-169.177~16.04.1
4.15.0-169.177~16.04.1
ubuntu/linux-oracle<4.15.0-1087.95~16.04.1
4.15.0-1087.95~16.04.1
ubuntu/linux<4.4.0-290.324
4.4.0-290.324
ubuntu/linux-aws<4.4.0-1199.214
4.4.0-1199.214
ubuntu/linux-hwe-edge*
ubuntu/linux-kvm<4.4.0-1162.173
4.4.0-1162.173
ubuntu/linux-fips<4.4.0-1131.138
4.4.0-1131.138
ubuntu/linux-fips*
ubuntu/linux<4.15.0-169.177
4.15.0-169.177
ubuntu/linux-aws<4.15.0-1121.129
4.15.0-1121.129
ubuntu/linux-aws-5.4<5.4.0-1069.73~18.04.1
5.4.0-1069.73~18.04.1
ubuntu/linux-azure-4.15<4.15.0-1131.144
4.15.0-1131.144
ubuntu/linux-azure-5.4<5.4.0-1073.76~18.04.1
5.4.0-1073.76~18.04.1
ubuntu/linux-dell300x<4.15.0-1035.40
4.15.0-1035.40
ubuntu/linux-gcp-4.15<4.15.0-1116.130
4.15.0-1116.130
ubuntu/linux-gcp-5.4<5.4.0-1068.72~18.04.1
5.4.0-1068.72~18.04.1
ubuntu/linux-gke-5.4<5.4.0-1066.69~18.04.1
5.4.0-1066.69~18.04.1
ubuntu/linux-gkeop-5.4<5.4.0-1037.38~18.04.1
5.4.0-1037.38~18.04.1
ubuntu/linux-hwe-5.4<5.4.0-105.119~18.04.1
5.4.0-105.119~18.04.1
ubuntu/linux-ibm-5.4<5.4.0-1018.20~18.04.1
5.4.0-1018.20~18.04.1
ubuntu/linux-kvm<4.15.0-1107.109
4.15.0-1107.109
ubuntu/linux-oracle<4.15.0-1087.95
4.15.0-1087.95
ubuntu/linux-oracle-5.4<5.4.0-1067.72~18.04.1
5.4.0-1067.72~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1056.63~18.04.1
5.4.0-1056.63~18.04.1
ubuntu/linux-raspi2<4.15.0-1103.110
4.15.0-1103.110
ubuntu/linux-snapdragon<4.15.0-1120.129
4.15.0-1120.129
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-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-fips<4.15.0-2061.63
4.15.0-2061.63
ubuntu/linux-azure-fips<4.15.0-2043.47
4.15.0-2043.47
ubuntu/linux-fips<4.15.0-1078.87
4.15.0-1078.87
ubuntu/linux-gcp-fips<4.15.0-2026.28
4.15.0-2026.28
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.4.0-105.119
5.4.0-105.119
ubuntu/linux-aws<5.4.0-1069.73
5.4.0-1069.73
ubuntu/linux-aws-5.13<5.13.0-1019.21~20.04.1
5.13.0-1019.21~20.04.1
ubuntu/linux-azure<5.4.0-1073.76
5.4.0-1073.76
ubuntu/linux-azure-5.13<5.13.0-1021.24~20.04.1
5.13.0-1021.24~20.04.1
ubuntu/linux-bluefield<5.4.0-1032.35
5.4.0-1032.35
ubuntu/linux-gcp<5.4.0-1068.72
5.4.0-1068.72
ubuntu/linux-gcp-5.13<5.13.0-1021.25~20.04.1
5.13.0-1021.25~20.04.1
ubuntu/linux-gke<5.4.0-1066.69
5.4.0-1066.69
ubuntu/linux-gkeop<5.4.0-1037.38
5.4.0-1037.38
ubuntu/linux-hwe-5.13<5.13.0-37.42~20.04.1
5.13.0-37.42~20.04.1
ubuntu/linux-ibm<5.4.0-1018.20
5.4.0-1018.20
ubuntu/linux-kvm<5.4.0-1059.62
5.4.0-1059.62
ubuntu/linux-oem-5.14<5.14.0-1022.24
5.14.0-1022.24
ubuntu/linux-oracle<5.4.0-1067.72
5.4.0-1067.72
ubuntu/linux-oracle-5.13<5.13.0-1025.30~20.04.1
5.13.0-1025.30~20.04.1
ubuntu/linux-raspi<5.4.0-1056.63
5.4.0-1056.63
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.8*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.8*
ubuntu/linux-hwe-5.11*
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-5.8*
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<5.4.0-1046.52
5.4.0-1046.52
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-intel-iot-realtime*
ubuntu/linux-realtime*
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 4.15.0-1131.144~14.04.1
  2. Upgrade

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

    Fixed in 4.4.0-1161.167
  3. Upgrade

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

    Fixed in 4.4.0-290.324~14.04.1
  4. Upgrade

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

    Fixed in 4.15.0-1120.128~16.04.1
  5. Upgrade

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

    Fixed in 4.15.0-1131.144~16.04.1
  6. Upgrade

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

    Fixed in 4.15.0-1116.130~16.04.1
  7. Upgrade

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

    Fixed in 4.15.0-169.177~16.04.1
  8. Upgrade

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

    Fixed in 4.15.0-1087.95~16.04.1
  9. Upgrade

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

    Fixed in 4.4.0-290.324
  10. Upgrade

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

    Fixed in 4.4.0-1199.214
  11. Upgrade

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

    Fixed in 4.4.0-1162.173
  12. Upgrade

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

    Fixed in 4.4.0-1131.138
  13. Upgrade

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

    Fixed in 4.15.0-169.177
  14. Upgrade

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

    Fixed in 4.15.0-1121.129
  15. Upgrade

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

    Fixed in 5.4.0-1069.73~18.04.1
  16. Upgrade

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

    Fixed in 4.15.0-1131.144
  17. Upgrade

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

    Fixed in 5.4.0-1073.76~18.04.1
  18. Upgrade

    Upgrade ubuntu/linux-dell300x to a version that resolves this vulnerability.

    Fixed in 4.15.0-1035.40
  19. Upgrade

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

    Fixed in 4.15.0-1116.130
  20. Upgrade

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

    Fixed in 5.4.0-1068.72~18.04.1
  21. Upgrade

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

    Fixed in 5.4.0-1066.69~18.04.1
  22. Upgrade

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

    Fixed in 5.4.0-1037.38~18.04.1
  23. Upgrade

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

    Fixed in 5.4.0-105.119~18.04.1
  24. Upgrade

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

    Fixed in 5.4.0-1018.20~18.04.1
  25. Upgrade

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

    Fixed in 4.15.0-1107.109
  26. Upgrade

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

    Fixed in 4.15.0-1087.95
  27. Upgrade

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

    Fixed in 5.4.0-1067.72~18.04.1
  28. Upgrade

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

    Fixed in 5.4.0-1056.63~18.04.1
  29. Upgrade

    Upgrade ubuntu/linux-raspi2 to a version that resolves this vulnerability.

    Fixed in 4.15.0-1103.110
  30. Upgrade

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

    Fixed in 4.15.0-1120.129
  31. Upgrade

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

    Fixed in 4.15.0-2061.63
  32. Upgrade

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

    Fixed in 4.15.0-2043.47
  33. Upgrade

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

    Fixed in 4.15.0-1078.87
  34. Upgrade

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

    Fixed in 4.15.0-2026.28
  35. Upgrade

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

    Fixed in 5.4.0-105.119
  36. Upgrade

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

    Fixed in 5.4.0-1069.73
  37. Upgrade

    Upgrade ubuntu/linux-aws-5.13 to a version that resolves this vulnerability.

    Fixed in 5.13.0-1019.21~20.04.1
  38. Upgrade

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

    Fixed in 5.4.0-1073.76
  39. Upgrade

    Upgrade ubuntu/linux-azure-5.13 to a version that resolves this vulnerability.

    Fixed in 5.13.0-1021.24~20.04.1
  40. Upgrade

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

    Fixed in 5.4.0-1032.35
  41. Upgrade

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

    Fixed in 5.4.0-1068.72
  42. Upgrade

    Upgrade ubuntu/linux-gcp-5.13 to a version that resolves this vulnerability.

    Fixed in 5.13.0-1021.25~20.04.1
  43. Upgrade

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

    Fixed in 5.4.0-1066.69
  44. Upgrade

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

    Fixed in 5.4.0-1037.38
  45. Upgrade

    Upgrade ubuntu/linux-hwe-5.13 to a version that resolves this vulnerability.

    Fixed in 5.13.0-37.42~20.04.1
  46. Upgrade

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

    Fixed in 5.4.0-1018.20
  47. Upgrade

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

    Fixed in 5.4.0-1059.62
  48. Upgrade

    Upgrade ubuntu/linux-oem-5.14 to a version that resolves this vulnerability.

    Fixed in 5.14.0-1022.24
  49. Upgrade

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

    Fixed in 5.4.0-1067.72
  50. Upgrade

    Upgrade ubuntu/linux-oracle-5.13 to a version that resolves this vulnerability.

    Fixed in 5.13.0-1025.30~20.04.1
  51. Upgrade

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

    Fixed in 5.4.0-1056.63
  52. Upgrade

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

    Fixed in 5.4.0-1069.73+fips2
  53. Upgrade

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

    Fixed in 5.4.0-1073.76+fips1
  54. Upgrade

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

    Fixed in 5.4.0-1046.52
  55. 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

Jan 6, 2022
CVE Published
via OSV·06:15 PM
Data Sourced
via OSV·06:15 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

Which systems are exposed to this issue?

Systems using the Linux netback driver for guest networking are exposed. The affected Ubuntu kernel package families listed are linux-fips, linux-azure, linux-aws, linux-aws-fips, linux-azure-fips, linux-gcp-fips, linux-gcp, and linux-oracle.

2

What must a guest do to trigger the memory exhaustion condition?

A guest needs to stop or constrain consumption of incoming packets so that its RX queue has only one free slot while the next packet requires multiple slots. The description identifies GSO, XDP, or software hashing as cases in which a packet may require more than one free slot, preventing the stall timeout from triggering.

3

What is the practical impact on the host?

A guest can cause the Linux netback driver to retain large amounts of kernel memory. This can result in host availability impact through kernel-memory exhaustion.

Company

Resources

Contact

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