Description
The do_fork function in Linux 2.4.x before 2.4.26, and 2.6.x before 2.6.6, does not properly decrement the mm_count counter when an error occurs after the mm_struct for a child process has been activated, which triggers a memory leak that allows local users to cause a denial of service (memory exhaustion) via the clone (CLONE_VM) system call.
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 3.0 | kernel-image-sparc-2.4 | 26woody1 | DSA-1070-1 |
| Debian 3.0 | kernel-patch-2.4.19-mips | 2.4.19-0.020911.1.woody5 | DSA-1070-1 |
| Debian 3.0 | kernel-source-2.4.16 | 2.4.16-1woody2 | DSA-1067-1 |
| Debian 3.0 | kernel-source-2.4.17 | 2.4.17-1woody4 | DSA-1082-1 |
| Debian 3.0 | kernel-source-2.4.18 | 2.4.18-14.4 | DSA-1069-1 |
| Debian 3.0 | kernel-source-2.4.19 | 2.4.19-4.woody3 | DSA-1070-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 3 | kernel +8 | 2.4.21-15.0.2.EL | RHSA-2004:255 |
Advisories 5
- RHSA-2004:255 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1082-1 kernel-source-2.4.17 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1067-1 kernel-source-2.4.16 - several Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1069-1 kernel-source-2.4.18 - several Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1070-1 kernel-source-2.4.19 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- 20163 third-party-advisory
- RHSA-2004:327 vendor-advisory
- 11464 third-party-advisory
- http://linux.bkbits.net:8080/linux-2.6/cset%40407b1217x4jtqEkpFW2g_-RcF0726A
- linux-dofork-memory-leak(16002) vdb-entry
- DSA-1082 vendor-advisory
- RHSA-2004:255 vendor-advisory
- FEDORA-2004-111 vendor-advisory
- 11861 third-party-advisory
- [linux-kernel] 20040408 [PATCH]: 2.4/2.6 do_fork() error path memory leak mailing-list
- RHSA-2004:260 vendor-advisory
- SuSE-SA:2004:010 vendor-advisory
- DSA-1070 vendor-advisory
- oval:org.mitre.oval:def:10297 vdb-entry signature
- 20162 third-party-advisory
- MDKSA-2004:037 vendor-advisory
- 11891 third-party-advisory
- 11486 third-party-advisory
- TLSA-2004-14 vendor-advisory
- 11541 third-party-advisory
- http://linux.bkbits.net:8080/linux-2.4/cset%40407bf20eDeeejm8t36_tpvSE-8EFHA
- DSA-1067 vendor-advisory
- CLA-2004:846 vendor-advisory
- 10221 vdb-entry
- DSA-1069 vendor-advisory
- 11429 third-party-advisory
- oval:org.mitre.oval:def:2819 vdb-entry signature
- O-164 third-party-advisory government-resource
- 20202 third-party-advisory
- GLSA-200407-02 vendor-advisory
- 11892 third-party-advisory
- 20338 third-party-advisory