Public Date:
547251: CVE-2009-4307 kernel: ext4: avoid divide by zero when trying to mount a corrupted file system

The MITRE CVE dictionary describes this issue as:

The ext4_fill_flex_info function in fs/ext4/super.c in the Linux kernel before 2.6.32-git6 allows user-assisted remote attackers to cause a denial of service (divide-by-zero error and panic) via a malformed ext4 filesystem containing a super block with a large FLEX_BG group size (aka s_log_groups_per_flex value).

Find out more about CVE-2009-4307 from the MITRE CVE dictionary dictionary and NIST NVD.


Red Hat is aware of this issue and is tracking it via the following bug: The Linux kernel packages as shipped with Red Hat Enterprise Linux 3, 4 and Red Hat Enterprise MRG do not include support for EXT4, and therefore are not affected by this issue. A future kernel update for Red Hat Enterprise Linux 5 will address this flaw.

CVSS v2 metrics

NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.

Base Score 4.9
Base Metrics AV:L/AC:L/Au:N/C:N/I:N/A:C
Access Vector Local
Access Complexity Low
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Complete

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux EUS (v. 5.4 server) (kernel) RHSA-2010:0380 2010-04-27
Red Hat Enterprise Linux version 5 (kernel) RHSA-2010:0178 2010-03-29