CVE-2017-18202 Use after free in n/a

High 7.0 Published 27 Feb 2018 Updated 5 Aug 2024

Attackers can trigger a use-after-free in the Linux kernel OOM reaper, causing denial of service or potential code execution.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2017-18202?

CVE-2017-18202 is a high-severity use after free vulnerability in Linux kernel, published on 27 Feb 2018. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

The __oom_reap_task_mm function in mm/oom_kill.c in the Linux kernel before 4.14.4 mishandles gather operations, which allows attackers to cause a denial of service (TLB entry leak or use-after-free) or possibly have unspecified other impact by triggering a copy_to_user call within a certain time window.

Weakness: CWE-416

Which versions are affected by CVE-2017-18202?

It affects 1 product.

Linux distribution packages (25)

`kernel` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-abi-whitelists` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-alt` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-bootwrapper` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debug` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debug-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debug-devel` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debuginfo-common-aarch64` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debuginfo-common-ppc64le` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-debuginfo-common-s390x` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-devel` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-doc` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-headers` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-kdump` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-kdump-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-kdump-devel` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-tools` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-tools-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-tools-libs` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`kernel-tools-libs-devel` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`perf` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`perf-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`python-perf` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`
`python-perf-debuginfo` Red Hat:enterprise_linux:7::server	All versions	`0:4.14.0-49.13.1.el7a`

Products include Linux kernel.

How do I fix CVE-2017-18202?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2017-18202 being exploited?

There is no known exploitation of CVE-2017-18202 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as DEBIAN-CVE-2017-18202, GHSA-wrf2-jc8v-7g96, RHSA-2018:2772, UBUNTU-CVE-2017-18202.