Description
An issue was discovered in mm/mmap.c in the Linux kernel before 5.7.11. There is a race condition between certain expand functions (expand_downwards and expand_upwards) and page-table free operations from an munmap call, aka CID-246c320a8cfe.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 5.7.17-1 | — |
| Debian 13 | linux | 5.7.17-1 | — |
| Debian 12 | linux | 5.7.17-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-45.49 | — |
| Ubuntu 20.04 LTS | linux-aws +2 | 5.4.0-1022.22 | — |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1023.23 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1021.21 | — |
| Ubuntu 20.04 LTS | linux-oem-5.6 | 5.6.0-1048.52 | USN-4752-1 |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1016.17 | — |
| Ubuntu 20.04 LTS | linux-raspi2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv | 5.4.0-31.35 | — |
| Ubuntu 18.04 LTS | linux-aws-5.4 +2 | 5.4.0-1022.22~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1023.23~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +11 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-45.49~18.04.2 | — |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1016.17~18.04.1 | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-aws-fips +2 | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1069.73+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1073.76+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | kernel-azure +2 | 5.3.18-18.29.1 | SUSE-SU-2020:3713-1 |
| SLES 15 SP2 | kernel-default-base | 5.3.18-24.43.2.9.17.3 | SUSE-SU-2020:3748-1 |
| SLES 15 SP2 | kernel-docs +5 | 5.3.18-24.43.2 | SUSE-SU-2020:3748-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Live Patching 15 SP2 | kernel-default | 5.3.18-24.43.2 | SUSE-SU-2020:3748-1 |
| SLE Live Patching 15 SP2 | kernel-livepatch-SLE15-SP2_Update_0 | 6-5.2 | SUSE-SU-2020:3843-1 |
| SLE Live Patching 15 SP2 | kernel-livepatch-SLE15-SP2_Update_8 | 1-5.3.3 | SUSE-SU-2020:3748-1 |
| SUSE Real Time Module 15 SP2 | kernel-rt +3 | 5.3.18-19.1 | SUSE-SU-2020:3764-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | kernel-default-base | 5.3.18-lp152.54.1.lp152.8.12.1 | openSUSE-SU-2020:2260-1, openSUSE-SU-2020:2161-1 |
| openSUSE Leap 15.2 | kernel-docs | 5.3.18-lp152.54.2 | openSUSE-SU-2020:2161-1 |
| openSUSE Leap 15.2 | kernel-rt +3 | 5.3.18-lp152.3.5.1 | openSUSE-SU-2021:0242-1 |
| openSUSE Leap 15.2 | kernel-syms +7 | 5.3.18-lp152.54.1 | openSUSE-SU-2020:2161-1 |
Advisories 8
- USN-4752-1 linux-oem-5.6 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- openSUSE-SU-2020:2260-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3764-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0242-1 Security update for RT kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3843-1 Security update for the Linux Kernel (Live Patch 0 for SLE 15 SP2) SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:2161-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3713-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3748-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.11
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=246c320a8cfe0b11d81a4af38fa9985ef0cc9a4c
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2056
- https://security.netapp.com/advisory/ntap-20210115-0001/
- [oss-security] 20210210 Re: CVE-2021-20200: Linux kernel: close race between munmap() and expand_upwards()/downwards() mailing-list
- [oss-security] 20210219 Re: CVE-2021-20200: Linux kernel: close race between munmap() and expand_upwards()/downwards() mailing-list