Description
An issue was discovered in the Linux kernel through 5.6.2. mpol_parse_str in mm/mempolicy.c has a stack-based out-of-bounds write because an empty nodelist is mishandled during mount option parsing, aka CID-aa9f7d5172fa. NOTE: Someone in the security community disagrees that this is a vulnerability because the issue “is a bug in parsing mount options which can only be specified by a privileged user, so triggering the bug does not grant any powers not already held.”
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 | 5.5.17-1 | — |
| Debian 13 | linux | 5.5.17-1 | — |
| Debian 12 | linux | 5.5.17-1 | — |
| Debian 10 | linux | 4.19.98-1+deb10u1 | DSA-4667-1 |
| Debian 9 | linux | 4.9.210-1+deb9u1 | DSA-4698-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 8 | linux | 3.16.84-1 | DLA-2241-1 |
| Debian 8 | linux-4.9 | 4.9.210-1+deb9u1~deb8u1 | DLA-2242-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-31.35 | USN-4367-1 |
| Ubuntu 20.04 LTS | linux-aws +4 | 5.4.0-1011.11 | USN-4367-1 |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1012.12 | USN-4367-1 |
| Ubuntu 20.04 LTS | linux-gke +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-oem-5.6 | 5.6.0-1008.8 | — |
| Ubuntu 20.04 LTS | linux-riscv | 5.4.0-26.30 | USN-4367-1 |
| Ubuntu 18.04 LTS | linux | 4.15.0-101.102 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1067.71 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-aws-5.3 | 5.3.0-1019.21~18.04.1 | USN-4369-1 |
| Ubuntu 18.04 LTS | linux-azure-4.15 | 4.15.0-1083.93 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-azure-5.3 | 5.3.0-1022.23~18.04.1 | USN-4369-1 |
| Ubuntu 18.04 LTS | linux-gcp +6 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-5.3 +1 | 5.3.0-1020.22~18.04.1 | USN-4369-1 |
| Ubuntu 18.04 LTS | linux-gke-4.15 | 4.15.0-1059.62 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-gke-5.0 | 5.0.0-1037.38 | USN-4368-1 |
| Ubuntu 18.04 LTS | linux-hwe | 5.3.0-53.47~18.04.1 | USN-4369-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1060.61 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1081.91 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-oem-osp1 | 5.0.0-1052.57 | USN-4368-1 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1039.43 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-oracle-5.3 | 5.3.0-1018.20~18.04.1 | USN-4369-1 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1062.66 | USN-4363-1 |
| Ubuntu 18.04 LTS | linux-raspi2-5.3 | 5.3.0-1026.28~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1079.86 | USN-4363-1 |
| Ubuntu 16.04 LTS | linux | 4.4.0-179.209 | USN-4364-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1107.118 | USN-4364-1 |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1067.71~16.04.1 | USN-4363-1 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1083.93~16.04.1 | USN-4363-1 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1071.81~16.04.1 | USN-4363-1 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-101.102~16.04.1 | USN-4363-1 |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1071.78 | USN-4364-1 |
| Ubuntu 16.04 LTS | linux-oracle | 4.15.0-1039.43~16.04.1 | USN-4363-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1133.142 | USN-4364-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1137.145 | USN-4364-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 18.04 LTS | linux-aws-fips +2 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-aws-fips | 4.15.0-2018.18 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-azure-fips | 4.15.0-2006.7 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips | 4.15.0-1029.34 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1034.39 | — |
| Ubuntu Pro 14.04 LTS | linux | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws | 4.4.0-1067.71 | USN-4364-1 |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1083.93~14.04.1 | — |
| Ubuntu Pro 14.04 LTS | linux-lts-xenial | 4.4.0-179.209~14.04.1 | USN-4364-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | kernel-rt +12 | 4.18.0-240.rt7.54.el8 | RHSA-2020:4609 |
| RHEL 8 | perf +26 | 4.18.0-240.el8 | RHSA-2020:4431 |
| RHEL 7 | kernel-alt | 4.14.0-115.26.1.el7a | RHSA-2020:2854 |
| RHEL 7 | kernel-rt +10 | 3.10.0-1160.rt56.1131.el7 | RHSA-2020:4062 |
| RHEL 7 | perf +18 | 3.10.0-1160.el7 | RHSA-2020:4060, RHSA-2020:2854 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | kernel-tools-libs-devel | 4.18.0-240.el8 | ALSA-2020:4431 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | perf +19 | 4.18.0-240.el8 | ELSA-2020-4431 |
| Oracle Linux 7 | perf +12 | 3.10.0-1160.el7 | ELSA-2020-4060 |
Advisories 17
- ALSA-2020:4431 Moderate: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2020:4431 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2020:4062 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- RHSA-2020:4060 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- RHSA-2020:4609 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2020:2854 Red Hat Security Advisory: kernel-alt security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- USN-4368-1 linux-gke-5.0, linux-oem-osp1 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4369-1 linux, linux-aws, linux-aws-5.3, linux-azure, linux-azure-5.3, linux-gcp, linux-gcp-5.3, linux-gke-5.3, linux-hwe, linux-kvm, linux-oracle, linux-oracle-5.3, linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4364-1 linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4363-1 linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gke-4.15, linux-hwe, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4367-1 linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oracle, linux-raspi, linux-riscv vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- DSA-4667-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4698-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2242-1 linux-4.9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2241-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- ELSA-2020-4431 Moderate: kernel security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
- ELSA-2020-4060 Important: kernel security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 6, 2020
References
- https://github.com/torvalds/linux/commit/aa9f7d5172fac9bf1f09e678c35e287a40a7b7dd
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=aa9f7d5172fac9bf1f09e678c35e287a40a7b7dd
- DSA-4667 vendor-advisory
- USN-4364-1 vendor-advisory
- USN-4367-1 vendor-advisory
- USN-4368-1 vendor-advisory
- USN-4363-1 vendor-advisory
- USN-4369-1 vendor-advisory
- [debian-lts-announce] 20200609 [SECURITY] [DLA 2241-1] linux security update mailing-list
- [debian-lts-announce] 20200610 [SECURITY] [DLA 2242-1] linux-4.9 security update mailing-list
- [debian-lts-announce] 20200610 [SECURITY] [DLA 2241-2] linux security update mailing-list
- DSA-4698 vendor-advisory