Description
The freelist-randomization feature in mm/slab.c in the Linux kernel 4.8.x and 4.9.x before 4.9.5 allows local users to cause a denial of service (duplicate freelist entries and system crash) or possibly have unspecified other impact in opportunistic circumstances by leveraging the selection of a large value for a random number.
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 | 4.9.6-1 | — |
| Debian 13 | linux | 4.9.6-1 | — |
| Debian 12 | linux | 4.9.6-1 | — |
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-gke +3 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +2 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe | 4.10.0-32.36~16.04.1 | USN-3361-1 |
Advisories 1
- USN-3361-1 linux-hwe vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
References
- https://github.com/torvalds/linux/commit/c4e490cf148e85ead0d1b1c2caaba833f1d5b29f
- [oss-security] 20170120 Re: CVE REQUEST: linux kernel: process with pgid zero able to crash kernel mailing-list
- https://bugzilla.redhat.com/show_bug.cgi?id=1415733
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c4e490cf148e85ead0d1b1c2caaba833f1d5b29f
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.5
- 95711 vdb-entry