Description
The (1) real_lookup and (2) __lookup_hash functions in fs/namei.c in the vfs implementation in the Linux kernel before 2.6.25.15 do not prevent creation of a child dentry for a deleted (aka S_DEAD) directory, which allows local users to cause a denial of service ("overflow" of the UBIFS orphan area) via a series of attempted file creations within deleted directories.
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.22etch2 | DSA-1630-1 |
| Debian 4.0 | linux-2.6 | 2.6.18.dfsg.1-22etch2 | DSA-1630-1 |
| Debian 4.0 | linux-2.6.24 | 2.6.24-6~etchnhalf.5 | DSA-1636-1 |
| Debian 4.0 | user-mode-linux | 2.6.18-1um-2etch.22etch2 | DSA-1630-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +12 | 2.6.18-92.1.13.el5 | RHSA-2008:0885 |
| RHEL 4 | kernel +10 | 2.6.9-78.0.13.EL | RHSA-2009:0014 |
| RHEL 3 | kernel +8 | 2.4.21-58.EL | RHSA-2008:0973 |
| RHEL 2 | kernel +8 | 2.4.9-e.74 | RHSA-2009:0001, RHSA-2008:0787 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat MRG 1 | kernel-rt +9 | 2.6.24.7-81.el5rt | RHSA-2008:0857 |
Advisories 8
- RHSA-2008:0885 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2009:0001 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2009:0014 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2008:0973 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1630-1 fai-kernels linux-2.6 user-mode-linux - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1636-1 linux-2.6.24 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- RHSA-2008:0787 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2008:0857 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Nov 22, 2025
References
- DSA-1630 vendor-advisory
- RHSA-2008:0885 vendor-advisory
- USN-637-1 vendor-advisory
- [linux-kernel] 20080702 Is VFS behavior fine? mailing-list
- 32190 third-party-advisory
- oval:org.mitre.oval:def:6551 vdb-entry signature
- DSA-1636 vendor-advisory
- 31614 third-party-advisory
- 31881 third-party-advisory
- 32104 third-party-advisory
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=d70b67c8bc72ee23b55381bd6a884f4796692f77
- 31551 third-party-advisory
- ADV-2008-2430 vdb-entry
- RHSA-2008:0857 vendor-advisory
- RHSA-2009:0014 vendor-advisory
- SUSE-SA:2008:048 vendor-advisory
- 1020739 vdb-entry
- 33280 third-party-advisory
- 33556 third-party-advisory
- 30647 vdb-entry
- 32023 third-party-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=457858
- MDVSA-2008:220 vendor-advisory
- 32344 third-party-advisory
- linux-kernel-ubifs-dos(44410) vdb-entry
- RHSA-2008:0973 vendor-advisory
- 31836 third-party-advisory
- http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.25.15
- RHSA-2008:0787 vendor-advisory
- SUSE-SA:2008:049 vendor-advisory
- 33201 third-party-advisory
- oval:org.mitre.oval:def:10744 vdb-entry signature