Description
The mq_open system call in Linux kernel 2.6.9, in certain situations, can decrement a counter twice ("double decrement") as a result of multiple calls to the mntput function when the dentry_open function call fails, which allows local users to cause a denial of service (panic) via unspecified attack vectors.
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 3.1 | kernel-source-2.6.8 | 2.6.8-16sarge2 | DSA-1017-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 4 | kernel +6 | 2.6.9-22.0.2.EL | RHSA-2006:0101 |
Advisories 2
- RHSA-2006:0101 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1017-1 kernel-source-2.6.8 - several Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=7c7dce9209161eb260cdf9e9172f72c3a02379e6
- 18788 third-party-advisory
- 19038 third-party-advisory
- http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=169130
- MDKSA-2006:040 vendor-advisory
- oval:org.mitre.oval:def:10731 vdb-entry signature
- RHSA-2006:0101 vendor-advisory
- linux-double-decrement-dos(25302) vdb-entry
- SUSE-SA:2006:006 vendor-advisory
- FLSA:157459-4 vendor-advisory
- 18510 third-party-advisory
- 16283 vdb-entry
- SUSE-SA:2006:012 vendor-advisory
- FLSA:157459-3 vendor-advisory
- DSA-1017 vendor-advisory
- USN-244-1 vendor-advisory
- 18527 third-party-advisory
- 19374 third-party-advisory