CVE-2020-27675: Race Condition

Published Oct 22, 2020
·
Updated

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/eventsbase.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5.

Affected Software

83 affected componentsFixes available
Linux Linux kernel<=5.9.1
Fedoraproject Fedora=31
Fedoraproject Fedora=32
Fedoraproject Fedora=33
Debian Debian Linux=9.0
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.25-16.12.27-1
ubuntu/linux-aws<4.4.0-1083.87
4.4.0-1083.87
ubuntu/linux-azure<4.15.0-1103.114~14.04.1
4.15.0-1103.114~14.04.1
ubuntu/linux-lts-xenial<4.4.0-198.230~14.04.1
4.4.0-198.230~14.04.1
ubuntu/linux*
ubuntu/linux<4.4.0-198.230
4.4.0-198.230
ubuntu/linux-aws<4.4.0-1119.133
4.4.0-1119.133
ubuntu/linux-aws-hwe<4.15.0-1091.96~16.04.1
4.15.0-1091.96~16.04.1
ubuntu/linux-azure<4.15.0-1103.114~16.04.1
4.15.0-1103.114~16.04.1
ubuntu/linux-gcp<4.15.0-1091.104~16.04.1
4.15.0-1091.104~16.04.1
ubuntu/linux-hwe<4.15.0-129.132~16.04.1
4.15.0-129.132~16.04.1
ubuntu/linux-kvm<4.4.0-1085.94
4.4.0-1085.94
ubuntu/linux-oracle<4.15.0-1062.68~16.04.1
4.15.0-1062.68~16.04.1
ubuntu/linux-raspi2<4.4.0-1143.153
4.4.0-1143.153
ubuntu/linux-snapdragon<4.4.0-1147.157
4.4.0-1147.157
ubuntu/linux-hwe-edge*
ubuntu/linux-fips<4.4.0-1052.58
4.4.0-1052.58
ubuntu/linux-fips*
ubuntu/linux<4.15.0-129.132
4.15.0-129.132
ubuntu/linux-aws<4.15.0-1091.96
4.15.0-1091.96
ubuntu/linux-aws-5.4<5.4.0-1034.35~18.04.1
5.4.0-1034.35~18.04.1
ubuntu/linux-azure-4.15<4.15.0-1103.114
4.15.0-1103.114
ubuntu/linux-azure-5.4<5.4.0-1035.36~18.04.1
5.4.0-1035.36~18.04.1
ubuntu/linux-dell300x<4.15.0-1010.14
4.15.0-1010.14
ubuntu/linux-gcp-4.15<4.15.0-1091.104
4.15.0-1091.104
ubuntu/linux-gcp-5.4<5.4.0-1033.35~18.04.1
5.4.0-1033.35~18.04.1
ubuntu/linux-gke-4.15<4.15.0-1077.82
4.15.0-1077.82
ubuntu/linux-gke-5.4<5.4.0-1033.35~18.04.1
5.4.0-1033.35~18.04.1
ubuntu/linux-gkeop-5.4<5.4.0-1008.9~18.04.1
5.4.0-1008.9~18.04.1
ubuntu/linux-hwe-5.4<5.4.0-59.65~18.04.1
5.4.0-59.65~18.04.1
ubuntu/linux-kvm<4.15.0-1082.84
4.15.0-1082.84
ubuntu/linux-oracle<4.15.0-1062.68
4.15.0-1062.68
ubuntu/linux-oracle-5.4<5.4.0-1034.36~18.04.1
5.4.0-1034.36~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1026.29~18.04.1
5.4.0-1026.29~18.04.1
ubuntu/linux-raspi2<4.15.0-1077.82
4.15.0-1077.82
ubuntu/linux-snapdragon<4.15.0-1094.103
4.15.0-1094.103
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-gcp-edge*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-fips<4.15.0-2034.35
4.15.0-2034.35
ubuntu/linux-azure-fips<4.15.0-2016.18
4.15.0-2016.18
ubuntu/linux-fips<4.15.0-1049.56
4.15.0-1049.56
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.4.0-59.65
5.4.0-59.65
ubuntu/linux-aws<5.4.0-1034.35
5.4.0-1034.35
ubuntu/linux-azure<5.4.0-1035.36
5.4.0-1035.36
ubuntu/linux-gcp<5.4.0-1033.35
5.4.0-1033.35
ubuntu/linux-hwe-5.8<5.8.0-44.50~20.04.1
5.8.0-44.50~20.04.1
ubuntu/linux-kvm<5.4.0-1031.32
5.4.0-1031.32
ubuntu/linux-oem-5.6<5.6.0-1050.54
5.6.0-1050.54
ubuntu/linux-oracle<5.4.0-1034.36
5.4.0-1034.36
ubuntu/linux-raspi<5.4.0-1026.29
5.4.0-1026.29
ubuntu/linux-riscv<5.4.0-40.45
5.4.0-40.45
ubuntu/linux-riscv-5.8<5.8.0-17.19~20.04.1
5.8.0-17.19~20.04.1
ubuntu/linux-azure-fde-5.15<5.15.0-1114.123~20.04.1
5.15.0-1114.123~20.04.1
ubuntu/linux-raspi2*
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-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-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 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 6.12.25-1Fixed in 6.12.27-1
  2. Upgrade

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

    Fixed in 4.4.0-1083.87
  3. Upgrade

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

    Fixed in 4.15.0-1103.114~14.04.1
  4. Upgrade

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

    Fixed in 4.4.0-198.230~14.04.1
  5. Upgrade

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

    Fixed in 4.4.0-198.230
  6. Upgrade

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

    Fixed in 4.4.0-1119.133
  7. Upgrade

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

    Fixed in 4.15.0-1091.96~16.04.1
  8. Upgrade

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

    Fixed in 4.15.0-1103.114~16.04.1
  9. Upgrade

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

    Fixed in 4.15.0-1091.104~16.04.1
  10. Upgrade

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

    Fixed in 4.15.0-129.132~16.04.1
  11. Upgrade

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

    Fixed in 4.4.0-1085.94
  12. Upgrade

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

    Fixed in 4.15.0-1062.68~16.04.1
  13. Upgrade

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

    Fixed in 4.4.0-1143.153
  14. Upgrade

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

    Fixed in 4.4.0-1147.157
  15. Upgrade

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

    Fixed in 4.4.0-1052.58
  16. Upgrade

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

    Fixed in 4.15.0-129.132
  17. Upgrade

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

    Fixed in 4.15.0-1091.96
  18. Upgrade

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

    Fixed in 5.4.0-1034.35~18.04.1
  19. Upgrade

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

    Fixed in 4.15.0-1103.114
  20. Upgrade

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

    Fixed in 5.4.0-1035.36~18.04.1
  21. Upgrade

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

    Fixed in 4.15.0-1010.14
  22. Upgrade

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

    Fixed in 4.15.0-1091.104
  23. Upgrade

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

    Fixed in 5.4.0-1033.35~18.04.1
  24. Upgrade

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

    Fixed in 4.15.0-1077.82
  25. Upgrade

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

    Fixed in 5.4.0-1033.35~18.04.1
  26. Upgrade

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

    Fixed in 5.4.0-1008.9~18.04.1
  27. Upgrade

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

    Fixed in 5.4.0-59.65~18.04.1
  28. Upgrade

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

    Fixed in 4.15.0-1082.84
  29. Upgrade

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

    Fixed in 4.15.0-1062.68
  30. Upgrade

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

    Fixed in 5.4.0-1034.36~18.04.1
  31. Upgrade

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

    Fixed in 5.4.0-1026.29~18.04.1
  32. Upgrade

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

    Fixed in 4.15.0-1077.82
  33. Upgrade

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

    Fixed in 4.15.0-1094.103
  34. Upgrade

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

    Fixed in 4.15.0-2034.35
  35. Upgrade

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

    Fixed in 4.15.0-2016.18
  36. Upgrade

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

    Fixed in 4.15.0-1049.56
  37. Upgrade

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

    Fixed in 5.4.0-59.65
  38. Upgrade

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

    Fixed in 5.4.0-1034.35
  39. Upgrade

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

    Fixed in 5.4.0-1035.36
  40. Upgrade

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

    Fixed in 5.4.0-1033.35
  41. Upgrade

    Upgrade ubuntu/linux-hwe-5.8 to a version that resolves this vulnerability.

    Fixed in 5.8.0-44.50~20.04.1
  42. Upgrade

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

    Fixed in 5.4.0-1031.32
  43. Upgrade

    Upgrade ubuntu/linux-oem-5.6 to a version that resolves this vulnerability.

    Fixed in 5.6.0-1050.54
  44. Upgrade

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

    Fixed in 5.4.0-1034.36
  45. Upgrade

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

    Fixed in 5.4.0-1026.29
  46. Upgrade

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

    Fixed in 5.4.0-40.45
  47. Upgrade

    Upgrade ubuntu/linux-riscv-5.8 to a version that resolves this vulnerability.

    Fixed in 5.8.0-17.19~20.04.1
  48. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.123~20.04.1
  49. Upgrade

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

    Fixed in 5.4.0-1069.73+fips2
  50. Upgrade

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

    Fixed in 5.4.0-1073.76+fips1
  51. 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

Oct 22, 2020
CVE Published
via MITRE·08:32 PM
Data Sourced
via MITRE·08:32 PM
Description
Data Sourced
via OSV·09:15 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2020-27675?

CVE-2020-27675 has a severe impact due to the potential for a use-after-free or NULL pointer dereference leading to system crashes.

2

How do I fix CVE-2020-27675?

To remediate CVE-2020-27675, upgrade your Linux kernel to version 5.10.223-1 or later, or applicable patched versions.

3

Which Linux versions are affected by CVE-2020-27675?

CVE-2020-27675 affects Linux kernels up to version 5.9.1 and certain Fedora and Debian releases.

4

What kind of issues can CVE-2020-27675 cause?

CVE-2020-27675 can lead to race conditions, causing unexpected behavior like crashes during event-handling in virtualization.

5

Is CVE-2020-27675 related to virtualization?

Yes, CVE-2020-27675 specifically affects the Linux kernel's handling of event channels in Xen virtualization.

Company

Resources

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