Description
The sanity_check_ckpt function in fs/f2fs/super.c in the Linux kernel before 4.12.4 does not validate the blkoff and segno arrays, which allows local users to gain privileges via unspecified vectors.
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 | 4.12.6-1 | — |
| Debian 13 | linux | 4.12.6-1 | — |
| Debian 12 | linux | 4.12.6-1 | — |
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 +4 | No fix yet | — |
| Ubuntu 16.04 LTS | linux | 4.4.0-96.119 | USN-3420-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1035.44 | USN-3420-1 |
| Ubuntu 16.04 LTS | linux-azure | 4.13.0-1005.7 | — |
| Ubuntu 16.04 LTS | linux-gcp | 4.10.0-1008.8 | USN-3468-3 |
| Ubuntu 16.04 LTS | linux-gke | 4.4.0-1031.31 | USN-3420-1 |
| Ubuntu 16.04 LTS | linux-hwe | 4.13.0-32.35~16.04.1 | USN-3468-2 |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1007.12 | USN-3420-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1074.82 | USN-3420-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1076.81 | USN-3420-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux | 3.13.0-135.184 | USN-3470-1 |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-96.119~14.04.1 | USN-3420-2 |
Advisories 5
- USN-3470-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3420-1 linux, linux-aws, linux-gke, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3468-2 linux-hwe vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3468-3 linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3420-2 linux-lts-xenial vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
References
- 100215 vdb-entry
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=15d3042a937c13f5d9244241c7a9c8416ff6e82a
- https://bugzilla.redhat.com/show_bug.cgi?id=1481149
- https://github.com/torvalds/linux/commit/15d3042a937c13f5d9244241c7a9c8416ff6e82a
- https://source.android.com/security/bulletin/2017-08-01
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.12.4