CVE-2008-3275: Medium severity linux kernel vulnerability
Description of problem: Zoltan Sogor noticed this VFS behaviour while testing UBIFS. Lookup can install a child dentry for a deleted directory. This keeps the directory dentry alive, and the inode pinned in the cache and on disk, even after all external references have gone away.
This isn't a big problem normally, since memory pressure or umount will clear out the directory dentry and its children, releasing the inode. But for UBIFS this causes problems because its orphan area can overflow.
http://lkml.org/lkml/2008/7/2/83 http://www.linux-mtd.infradead.org/doc/ubifs.html
Other sources
The (1) reallookup and (2) lookuphash 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 SDEAD) 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.
— MITRE
Affected Software
Remediation
Patch Available
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Event History
Frequently Asked Questions
What is the severity of CVE-2008-3275?
CVE-2008-3275 has a medium severity rating, as it involves the improper handling of deleted directory entries which can impact system stability.
How do I fix CVE-2008-3275?
To fix CVE-2008-3275, update the Linux kernel to versions later than 2.6.25.15 that address this vulnerability.
What are the affected operating systems for CVE-2008-3275?
Affected operating systems for CVE-2008-3275 include certain versions of the Linux kernel, Debian 4.0, and specific Ubuntu and SUSE Linux versions.
What is the impact of CVE-2008-3275?
CVE-2008-3275 can cause issues with system resource management, particularly by keeping deleted directory inodes alive in cache.
Who discovered CVE-2008-3275?
CVE-2008-3275 was discovered by Zoltan Sogor during testing of the UBIFS filesystem.