Description
The __qdisc_run function in net/sched/sch_generic.c in the Linux kernel before 2.6.25 on SMP machines allows local users to cause a denial of service (soft lockup) by sending a large amount of network traffic, as demonstrated by multiple simultaneous invocations of the Netperf benchmark application in UDP_STREAM mode.
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 4.0 | fai-kernels | 1.17+etch.24etch2 | DSA-1794-1 |
| Debian 4.0 | linux-2.6 | 2.6.18.dfsg.1-24etch2 | DSA-1794-1 |
| Debian 4.0 | user-mode-linux | 2.6.18-1um-2etch.24etch2 | DSA-1794-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +12 | 2.6.18-128.1.1.el5 | RHSA-2009:0264 |
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 2.6.x - 'qdisc_run()' Local Denial of Service EDB-32682 · dos · Dec 23, 2008 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- RHSA-2009:0264 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- DSA-1794-1 linux-2.6 - multiple vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- 33706 third-party-advisory
- [oss-security] 20081223 CVE request: kernel: soft lockup occurs when network load is very high mailing-list
- http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.27.y.git%3Ba=commit%3Bh=2ba2506ca7ca62c56edaa334b0fe61eb5eab6ab0
- DSA-1794 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=477744
- 35011 third-party-advisory
- oval:org.mitre.oval:def:9385 vdb-entry signature
- http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.25
- RHSA-2009:0264 vendor-advisory
- 33858 third-party-advisory
- 32985 vdb-entry
- USN-714-1 vendor-advisory