Description
net/unix/af_unix.c in the Linux kernel 2.6.31.4 and earlier allows local users to cause a denial of service (system hang) by creating an abstract-namespace AF_UNIX listening socket, performing a shutdown operation on this socket, and then performing a series of connect operations to this socket.
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 5.0 | linux-2.6 | 2.6.26-19lenny2 | DSA-1927-1 |
| Debian 4.0 | linux-2.6 | 2.6.18.dfsg.1-26etch1 | DSA-1929-1 |
| Debian 4.0 | linux-2.6.24 | 2.6.24-6~etchnhalf.9etch1 | DSA-1928-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +12 | 2.6.18-164.9.1.el5 | RHSA-2009:1670 |
| RHEL 4 | kernel +10 | 2.6.9-89.0.18.EL | RHSA-2009:1671 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat MRG 1 | kernel-rt +9 | 2.6.24.7-137.el5rt | RHSA-2009:1540 |
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 2.6.31.4 - 'unix_stream_connect()' Local Denial of Service EDB-10022 · dos · Nov 10, 2009 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 6
- RHSA-2009:1671 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2009:1540 Red Hat Security Advisory: kernel-rt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2009:1670 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- DSA-1929-1 linux-2.6 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1927-1 linux-2.6 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1928-1 linux-2.6.24 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- [oss-security] 20091019 CVE request: kernel: AF_UNIX: Fix deadlock on connecting to shutdown socket mailing-list
- https://bugzilla.redhat.com/show_bug.cgi?id=529626
- [linux-kernel] 20091019 Re: [PATCH] AF_UNIX: Fix deadlock on connecting to shutdown socket mailing-list
- RHSA-2009:1671 vendor-advisory
- [oss-security] 20091019 Re: CVE request: kernel: AF_UNIX: Fix deadlock on connecting to shutdown socket mailing-list
- RHSA-2009:1540 vendor-advisory
- SUSE-SA:2009:061 vendor-advisory
- USN-864-1 vendor-advisory
- 38794 third-party-advisory
- [security-announce] 20100303 VMSA-2010-0004 ESX Service Console and vMA third party updates mailing-list
- SUSE-SA:2010:001 vendor-advisory
- MDVSA-2009:329 vendor-advisory
- SUSE-SA:2010:012 vendor-advisory
- http://git.kernel.org/?p=linux/kernel/git/davem/net-2.6.git%3Ba=commit%3Bh=77238f2b942b38ab4e7f3aced44084493e4a8675
- 37909 third-party-advisory
- oval:org.mitre.oval:def:9921 vdb-entry signature
- http://patchwork.kernel.org/patch/54678/
- RHSA-2009:1670 vendor-advisory
- SUSE-SA:2009:064 vendor-advisory
- 38834 third-party-advisory
- oval:org.mitre.oval:def:6895 vdb-entry signature
- SUSE-SA:2010:013 vendor-advisory
- 37086 third-party-advisory
- 38017 third-party-advisory
- FEDORA-2009-11038 vendor-advisory
- ADV-2010-0528 vdb-entry