The ext4_isize function in fs/ext4/ext4.h in the Linux kernel 2.6.27 before 2.6.27.19 and 2.6.28 before 2.6.28.7 uses the i_size_high structure member during operations on arbitrary types of files, which allows local users to cause a denial of service (CPU consumption and error-message flood) by attempting to mount a crafted ext4 filesystem.

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-0747
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8585
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9200
• http://bugzilla.kernel.org/show_bug.cgi?id=12375
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=06a279d636734da32bb62dd2f7b0ade666f65d7c
• http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.27.19
• http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.28.7
• http://rhn.redhat.com/errata/RHSA-2009-1243.html
• http://secunia.com/advisories/34394
• http://secunia.com/advisories/36562
• http://secunia.com/advisories/37471
• http://www.debian.org/security/2009/dsa-1749
• http://www.securityfocus.com/archive/1/507985/100/0/threaded
• http://www.ubuntu.com/usn/usn-751-1
• http://www.vmware.com/security/advisories/VMSA-2009-0016.html
• http://www.vupen.com/english/advisories/2009/0509
• http://www.vupen.com/english/advisories/2009/3316