Description
The BPF subsystem in the Linux kernel before 4.5.5 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted application on (1) a system with more than 32 Gb of memory, related to the program reference count or (2) a 1 Tb system, related to the map reference count.
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 | 4.5.3-1 | — |
| Debian 13 | linux | 4.5.3-1 | — |
| Debian 12 | linux | 4.5.3-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux | 4.4.0-24.43 | USN-3006-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1012.16 | USN-3007-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1015.18 | — |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-24.43~14.04.1 | USN-3005-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 4.8.13-1.1 | openSUSE-SU-2024:10128-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Exploit-DB 1
- Linux Kernel (Ubuntu 16.04) - Reference Count Overflow Using BPF Maps EDB-39773 · dos · May 4, 2016 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 4
- USN-3006-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3005-1 linux-lts-xenial vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3007-1 linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- openSUSE-SU-2024:10128-1 kernel-debug-4.8.13-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- USN-3006-1 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1334303
- USN-3005-1 vendor-advisory
- https://github.com/torvalds/linux/commit/92117d8443bc5afacc8d5ba82e541946310f106e
- USN-3007-1 vendor-advisory
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.5.5
- [oss-security] 20160506 CVE Requests: Linux: BPF flaws (one use-after-free / local root privilege escalation) mailing-list
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=92117d8443bc5afacc8d5ba82e541946310f106e