CVE-2009-4895: Null Pointer Dereference
Description of problem: Changes to tty to use struct pid happened here: ab521dc0f8e117fd808d3e425216864d60390500
mrg-1/rhel-6 are missing: 1) redo locking of tty->pgrp 47f86834bbd4193139d61d659bebf9ab9d691e37 2) tty: fix race in ttyfasync 703625118069f9f8960d356676662d3db5a9d116 3) fnctl: fmodown should call writelockirqsave/restore b04da8bfdfbbd79544cab2fadfdc12e87eb01600
Other sources
Race condition in the ttyfasync function in drivers/char/ttyio.c in the Linux kernel before 2.6.32.6 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via unknown vectors, related to the putttyqueue and fsetown functions. NOTE: the vulnerability was addressed in a different way in 2.6.32.9.
— Launchpad
Affected Software
Remediation
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2009-4895?
CVE-2009-4895 has a medium severity due to potential race conditions affecting tty devices.
How do I fix CVE-2009-4895?
To fix CVE-2009-4895, apply the relevant patches from your Linux distribution that address the tty locking issues.
Which versions of Linux are affected by CVE-2009-4895?
CVE-2009-4895 affects various versions of the Linux kernel including those prior to 2.6.32.6 and specific Debian and Ubuntu releases.
What impact does CVE-2009-4895 have on system security?
CVE-2009-4895 can lead to privilege escalation or denial of service due to improper handling of concurrent tty operations.
What types of systems are running vulnerable software for CVE-2009-4895?
Systems running affected versions of the Linux kernel, Debian Linux 5.0, or specific Ubuntu releases like 6.06 to 10.10 are vulnerable to CVE-2009-4895.