Description
The Linux Kernel versions 4.14, 4.15, and 4.16 has a null pointer dereference which can result in an out of memory (OOM) killing of large mlocked processes. The issue arises from an oom killed process's final thread calling exit_mmap(), which calls munlock_vma_pages_all() for mlocked vmas.This can happen synchronously with the oom reaper's unmap_page_range() since the vma's VM_LOCKED bit is cleared before munlocking (to determine if any other vmas share the memory and are mlocked).
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 | 4.16.12-1 | — |
| Debian 13 | linux | 4.16.12-1 | — |
| Debian 12 | linux | 4.16.12-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux | 4.15.0-33.36 | USN-3752-1 |
| Ubuntu 18.04 LTS | linux-aws +1 | 4.15.0-1020.20 | USN-3752-1 |
| Ubuntu 18.04 LTS | linux-azure | 4.15.0-1022.23 | USN-3752-3 |
| Ubuntu 18.04 LTS | linux-gcp | 4.15.0-1018.19 | USN-3752-1 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1017.20 | USN-3752-3 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1021.23 | USN-3752-1 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1022.22~16.04.1 | USN-3752-3 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1018.19~16.04.2 | USN-3752-3 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-33.36~16.04.1 | USN-3752-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | perf +14 | 4.14.0-115.el7a | RHSA-2018:2948 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | kernel-docs +6 | 4.12.14-25.3.1 | SUSE-SU-2018:2092-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Live Patching 15 | kernel-default | 4.12.14-25.3.1 | SUSE-SU-2018:2092-1 |
| SLE Live Patching 15 | kernel-livepatch-SLE15_Update_1 | 1-1.3.1 | SUSE-SU-2018:2092-1 |
Advisories 5
- RHSA-2018:2948 Red Hat Security Advisory: kernel-alt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- USN-3752-1 linux, linux-aws, linux-gcp, linux-kvm, linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-3752-3 linux-azure, linux-oem, linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-3752-2 linux-hwe vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- SUSE-SU-2018:2092-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- USN-3752-2 vendor-advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=27ae357fa82be5ab73b2ef8d39dcb8ca2563483a
- USN-3752-3 vendor-advisory
- https://access.redhat.com/security/cve/cve-2018-1000200
- [linux-kernel] 20180424 [patch v3 for-4.17] mm, oom: fix concurrent munlock and oom reaper unmap mailing-list
- RHSA-2018:2948 vendor-advisory
- 104397 vdb-entry
- [linux-kernel] 20180417 [patch] mm, oom: fix concurrent munlock and oom reaper unmap mailing-list
- USN-3752-1 vendor-advisory
- [oss-security] 20180424 CVE-2018-1000200 (Linux): Bad memory access on oom kill of large mlocked process mailing-list