Description
The epoll implementation in the Linux kernel 2.6.37.2 and earlier does not properly traverse a tree of epoll file descriptors, which allows local users to cause a denial of service (CPU consumption) via a crafted application that makes epoll_create and epoll_ctl system calls.
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.
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | perf +14 | 2.6.32-279.el6 | RHSA-2012:0862 |
| RHEL 5 | kernel +11 | 2.6.18-308.el5 | RHSA-2012:0150 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6.2 EUS | perf +14 | 2.6.32-220.24.1.el6 | RHSA-2012:1129 |
| Red Hat MRG 2 | kernel-rt +10 | 3.0.25-rt44.57.el6rt | RHBA-2012:0496 |
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.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- Linux Kernel 2.6.x - epoll Nested Structures Local Denial of Service EDB-35403 · dos · Mar 2, 2011 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 4
- RHSA-2012:1129 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2012:0862 Red Hat Security Advisory: Red Hat Enterprise Linux 6 kernel security, bug fix and enhancement update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2012:0150 Red Hat Security Advisory: Red Hat Enterprise Linux 5.8 kernel update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHBA-2012:0496 Red Hat Bug Fix Advisory: Red Hat Enterprise MRG Realtime 2.1 kernel bug fix update Red Hat Security Advisories (RHSA) · Nov 22, 2025
References
- [linux-kernel] 20110226 Re: [PATCH] optimize epoll loop detection mailing-list
- 43522 third-party-advisory
- SUSE-SU-2012:0554 vendor-advisory
- [oss-security] 20110302 Re: CVE request: kernel: Multiple DoS issues in epoll mailing-list
- [linux-kernel] 20110228 Re: [PATCH] optimize epoll loop detection mailing-list
- 48898 third-party-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=681578
- 48410 third-party-advisory
- [linux-kernel] 20110225 [PATCH] optimize epoll loop detection mailing-list
- 48964 third-party-advisory
- [oss-security] 20110301 CVE request: kernel: Multiple DoS issues in epoll mailing-list
- SUSE-SU-2012:0616 vendor-advisory
- 48115 third-party-advisory
- RHSA-2012:0862 vendor-advisory
- 71265 vdb-entry