CVE-2020-29368
Publication date 28 November 2020
Last updated 24 July 2024
Ubuntu priority
An issue was discovered in __split_huge_pmd in mm/huge_memory.c in the Linux kernel before 5.7.5. The copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check, aka CID-c444eb564fb1.
From the Ubuntu Security Team
Jann Horn discovered a race condition in the copy-on-write implementation in the Linux kernel when handling hugepages. A local attacker could use this to gain unintended write access to read-only memory pages.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| linux | ||
| 20.04 LTS focal |
Fixed 5.4.0-45.49
|
|
| 18.04 LTS bionic |
Fixed 4.15.0-115.116
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Ignored | |
| linux-aws | ||
| 20.04 LTS focal |
Fixed 5.4.0-1022.22
|
|
| 18.04 LTS bionic |
Fixed 4.15.0-1080.84
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Ignored | |
| linux-aws-5.0 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-aws-5.3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-aws-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.4.0-1022.22~18.04.1
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-aws-hwe | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial |
Fixed 4.15.0-1080.84~16.04.1
|
|
| 14.04 LTS trusty | Not in release | |
| linux-azure | ||
| 20.04 LTS focal |
Fixed 5.4.0-1023.23
|
|
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial |
Fixed 4.15.0-1093.103~16.04.1
|
|
| 14.04 LTS trusty | Ignored | |
| linux-azure-4.15 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 4.15.0-1093.103
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-azure-5.3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-azure-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.4.0-1023.23~18.04.1
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-azure-edge | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-dell300x | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gcp | ||
| 20.04 LTS focal |
Fixed 5.4.0-1022.22
|
|
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial |
Fixed 4.15.0-1081.92~16.04.1
|
|
| 14.04 LTS trusty | Not in release | |
| linux-gcp-4.15 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 4.15.0-1081.92
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gcp-5.3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gcp-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.4.0-1022.22~18.04.1
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gcp-edge | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gke-4.15 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 4.15.0-1067.70
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gke-5.0 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.0.0-1045.46
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gke-5.3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.3.0-1032.34~18.04.1
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gke-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gkeop | ||
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-gkeop-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-hwe | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial |
Fixed 4.15.0-115.116~16.04.1
|
|
| 14.04 LTS trusty | Not in release | |
| linux-hwe-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.4.0-45.49~18.04.2
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-hwe-5.8 | ||
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-hwe-edge | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Ignored | |
| 14.04 LTS trusty | Not in release | |
| linux-kvm | ||
| 20.04 LTS focal |
Fixed 5.4.0-1021.21
|
|
| 18.04 LTS bionic |
Fixed 4.15.0-1072.73
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Not in release | |
| linux-lts-trusty | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-lts-xenial | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Ignored | |
| linux-oem | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 4.15.0-1094.104
|
|
| 16.04 LTS xenial | Ignored | |
| 14.04 LTS trusty | Not in release | |
| linux-oem-5.10 | ||
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-oem-5.6 | ||
| 20.04 LTS focal |
Fixed 5.6.0-1048.52
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-oem-osp1 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-oracle | ||
| 20.04 LTS focal |
Fixed 5.4.0-1022.22
|
|
| 18.04 LTS bionic |
Fixed 4.15.0-1051.55
|
|
| 16.04 LTS xenial |
Fixed 4.15.0-1051.55~16.04.1
|
|
| 14.04 LTS trusty | Not in release | |
| linux-oracle-5.0 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-oracle-5.3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-oracle-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.4.0-1022.22~18.04.1
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-raspi | ||
| 20.04 LTS focal |
Fixed 5.4.0-1016.17
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-raspi-5.4 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.4.0-1016.17~18.04.1
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-raspi2 | ||
| 20.04 LTS focal | Ignored | |
| 18.04 LTS bionic |
Fixed 4.15.0-1068.72
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Not in release | |
| linux-raspi2-5.3 | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 5.3.0-1030.32~18.04.2
|
|
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-riscv | ||
| 20.04 LTS focal |
Fixed 5.4.0-31.35
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| linux-snapdragon | ||
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic |
Fixed 4.15.0-1084.92
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Not in release |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
7.0 · High
|
| Attack vector | Local |
| Attack complexity | High |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
References
Related Ubuntu Security Notices (USN)
- USN-4752-1
- Linux kernel (OEM) vulnerabilities
- 25 February 2021
Other references
- https://git.kernel.org/linus/c444eb564fb16645c172d550359cb3d75fe8a040
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2045
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.5
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c444eb564fb16645c172d550359cb3d75fe8a040
- https://www.cve.org/CVERecord?id=CVE-2020-29368