Description
The Network Lock Manager (NLM) protocol implementation in the NFS client functionality in the Linux kernel before 3.0 allows local users to cause a denial of service (system hang) via a LOCK_UN flock 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 6.0 | linux-2.6 | 2.6.32-35squeeze1 | DSA-2303-1 |
| Debian 5.0 | linux-2.6 | 2.6.26-26lenny4 | DSA-2310-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | perf +14 | 2.6.32-131.12.1.el6 | RHSA-2011:1189 |
| RHEL 5 | kernel +11 | 2.6.18-274.3.1.el5 | RHSA-2011:1212 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5.6 EUS | kernel +11 | 2.6.18-238.31.1.el5 | RHSA-2011:1813 |
| Red Hat MRG 2 | kernel-rt +10 | 2.6.33.9-rt31.75.el6rt | RHSA-2011:1253 |
Advisories 6
- RHSA-2011:1813 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2011:1253 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2011:1212 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2011:1189 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- DSA-2303-1 linux-2.6 - several issues Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-2310-1 linux-2.6 - several issues Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://ftp.osuosl.org/pub/linux/kernel/v3.0/ChangeLog-3.0
- https://github.com/torvalds/linux/commit/0b760113a3a155269a3fba93a409c640031dd68f
- RHSA-2011:1212 vendor-advisory
- [oss-security] 20110623 Re: CVE request: kernel: NLM: Don't hang forever on NLM unlock requests mailing-list
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=0b760113a3a155269a3fba93a409c640031dd68f
- https://bugzilla.redhat.com/show_bug.cgi?id=709393