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UBUNTU-CVE-2021-26930 High

UBUNTU-CVE-2021-26930

An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen. To service requests to the PV backend, the driver maps grant references provided by the frontend. In this process, errors may be encountered. In one case, an error encountered earlier might be discarded by later processing, resulting in the caller assuming successful mapping, and hence subsequent operations trying to access space that wasn't mapped. In another case, internal state would be insufficiently updated, preventing safe recovery from the error. This affects drivers/block/xen-blkback/blkback.c.

Exploit probability Not scored
Published February 17, 2021
Required by Not available
Last source change August 18, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:16.04:LTS linux-snapdragon

92 explicit affected versions

Ubuntu:18.04:LTS linux-oem

50 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.0

6 explicit affected versions

Ubuntu:20.04:LTS linux-raspi2

6 explicit affected versions

Ubuntu:Pro:20.04:LTS linux-azure-fde-5.15

57 explicit affected versions

Ubuntu:Pro:14.04:LTS linux

191 explicit affected versions

Ubuntu:18.04:LTS linux-aws

64 explicit affected versions

Ubuntu:20.04:LTS linux-kvm

23 explicit affected versions

Ubuntu:18.04:LTS linux-oracle

44 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-azure-fips

17 explicit affected versions

Ubuntu:18.04:LTS linux

74 explicit affected versions

Ubuntu:16.04:LTS linux-hwe-edge

23 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:24.04:LTS linux-raspi-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-hwe-5.8

17 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.0

7 explicit affected versions

Ubuntu:20.04:LTS linux-riscv

12 explicit affected versions

Ubuntu:22.04:LTS linux-intel-iot-realtime

1 explicit affected versions

Ubuntu:20.04:LTS linux-gcp

25 explicit affected versions

Ubuntu:20.04:LTS linux

33 explicit affected versions

Ubuntu:16.04:LTS linux-kvm

60 explicit affected versions

Ubuntu:20.04:LTS linux-azure

24 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-4.15

19 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-edge

10 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.4

10 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-aws

59 explicit affected versions

Ubuntu:18.04:LTS linux-snapdragon

41 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.10

5 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-oem-5.6

29 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.3

13 explicit affected versions

Ubuntu:18.04:LTS linux-kvm

58 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:20.04:LTS linux-aws

27 explicit affected versions

Ubuntu:18.04:LTS linux-gke-4.15

33 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.3

10 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-aws-hwe

43 explicit affected versions

Ubuntu:Nvidia-BlueField:24.04:LTS linux-bluefield

11 explicit affected versions

Ubuntu:16.04:LTS linux-raspi2

94 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-gcp

66 explicit affected versions

Ubuntu:20.04:LTS linux-oracle

25 explicit affected versions

Ubuntu:Pro:FIPS:16.04:LTS linux-fips

2 explicit affected versions

Ubuntu:18.04:LTS linux-raspi2

61 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-5.4

21 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:16.04:LTS linux

125 explicit affected versions

Ubuntu:20.04:LTS linux-gke

5 explicit affected versions

Ubuntu:18.04:LTS linux-azure-4.15

20 explicit affected versions

Ubuntu:Pro:FIPS:18.04:LTS linux-aws-fips

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-fips

23 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.4

15 explicit affected versions

Ubuntu:Pro:FIPS:20.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:18.04:LTS linux-aws-5.4

15 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-azure-fips

1 explicit affected versions

Ubuntu:Pro:FIPS-updates:18.04:LTS linux-aws-fips

20 explicit affected versions

Ubuntu:20.04:LTS linux-riscv-5.8

7 explicit affected versions

Ubuntu:16.04:LTS linux-aws

81 explicit affected versions

Ubuntu:18.04:LTS linux-raspi-5.4

14 explicit affected versions

Ubuntu:18.04:LTS linux-azure

44 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.3

16 explicit affected versions

Ubuntu:18.04:LTS linux-gkeop-5.4

10 explicit affected versions

Ubuntu:18.04:LTS linux-gcp

38 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.3

9 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-lts-xenial

103 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.4

15 explicit affected versions

Ubuntu:Pro:FIPS:16.04:LTS linux-fips

38 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-azure

74 explicit affected versions

Ubuntu:Pro:14.04:LTS linux-azure

51 explicit affected versions

Ubuntu:18.04:LTS linux-dell300x

11 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-oracle

42 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.4

14 explicit affected versions

Ubuntu:18.04:LTS linux-hwe

43 explicit affected versions

Ubuntu:Pro:FIPS-updates:20.04:LTS linux-gcp-fips

1 explicit affected versions

Ubuntu:Pro:16.04:LTS linux-hwe

89 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-edge

12 explicit affected versions

Ubuntu:20.04:LTS linux-raspi

18 explicit affected versions

Ubuntu:18.04:LTS linux-azure-edge

4 explicit affected versions

Ubuntu:20.04:LTS linux-gkeop

5 explicit affected versions

Ubuntu:22.04:LTS linux-realtime

1 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities UBUNTU-CVE-2021-26930

An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen. To service requests to the PV backend, the driver maps grant references provided by the frontend. In this process, errors may be encountered. In one case, an error encountered earlier might be discarded by later processing, resulting in the caller assuming successful mapping, and hence subsequent operations trying to access space that wasn't mapped. In another case, internal state would be insufficiently updated, preventing safe recovery from the error. This affects drivers/block/xen-blkback/blkback.c.

View original source

05 / REFERENCES

Further evidence