BID:40867

Linux Kernel 'tty_fasync()' Race Condition Null Pointer Dereference Vulnerability

Info

Linux Kernel 'tty_fasync()' Race Condition Null Pointer Dereference Vulnerability

Bugtraq ID:	40867
Class:	Design Error
CVE:
Remote:	Yes
Local:	Yes
Published:	Nov 14 2009 12:00AM
Updated:	Oct 20 2010 07:49AM
Credit:	Kyle Bader
Vulnerable:	Ubuntu Ubuntu Linux 9.10 sparc Ubuntu Ubuntu Linux 9.10 powerpc Ubuntu Ubuntu Linux 9.10 lpia Ubuntu Ubuntu Linux 9.10 i386 Ubuntu Ubuntu Linux 9.10 amd64 Ubuntu Ubuntu Linux 9.04 sparc Ubuntu Ubuntu Linux 9.04 powerpc Ubuntu Ubuntu Linux 9.04 lpia Ubuntu Ubuntu Linux 9.04 i386 Ubuntu Ubuntu Linux 9.04 amd64 Ubuntu Ubuntu Linux 8.04 LTS sparc Ubuntu Ubuntu Linux 8.04 LTS powerpc Ubuntu Ubuntu Linux 8.04 LTS lpia Ubuntu Ubuntu Linux 8.04 LTS i386 Ubuntu Ubuntu Linux 8.04 LTS amd64 Ubuntu Ubuntu Linux 6.06 LTS sparc Ubuntu Ubuntu Linux 6.06 LTS powerpc Ubuntu Ubuntu Linux 6.06 LTS i386 Ubuntu Ubuntu Linux 6.06 LTS amd64 Ubuntu Ubuntu Linux 10.10 powerpc Ubuntu Ubuntu Linux 10.10 i386 Ubuntu Ubuntu Linux 10.10 amd64 Ubuntu Ubuntu Linux 10.04 sparc Ubuntu Ubuntu Linux 10.04 powerpc Ubuntu Ubuntu Linux 10.04 i386 Ubuntu Ubuntu Linux 10.04 amd64 Linux kernel 2.6.33 Linux kernel 2.6.32 Linux kernel 2.6.31 5 Linux kernel 2.6.31 .2 Linux kernel 2.6.31 .11 Linux kernel 2.6.31 -rc7 Linux kernel 2.6.31 -rc6 + Trustix Secure Enterprise Linux 2.0 + Trustix Secure Linux 2.2 + Trustix Secure Linux 2.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.31 -rc3 + Trustix Secure Enterprise Linux 2.0 + Trustix Secure Linux 2.2 + Trustix Secure Linux 2.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.31 -rc1 Linux kernel 2.6.31 Linux kernel 2.6.30 .10 Linux kernel 2.6.30 .1 Linux kernel 2.6.30 -rc6 Linux kernel 2.6.30 -rc5 Linux kernel 2.6.30 -rc3 Linux kernel 2.6.30 -rc2 Linux kernel 2.6.30 -rc1 Linux kernel 2.6.30 Linux kernel 2.6.27 6 Linux kernel 2.6.27 3 Linux kernel 2.6.27 12 Linux kernel 2.6.27 .5 Linux kernel 2.6.27 .5 Linux kernel 2.6.27 .24 Linux kernel 2.6.27 .14 Linux kernel 2.6.27 .13 Linux kernel 2.6.27 .12 Linux kernel 2.6.27 -rc8-git5 Linux kernel 2.6.27 -rc8 Linux kernel 2.6.27 -rc6-git6 Linux kernel 2.6.27 -rc6 Linux kernel 2.6.27 -rc5 Linux kernel 2.6.27 -rc4 Linux kernel 2.6.27 -rc2 Linux kernel 2.6.27 -rc1 Linux kernel 2.6.27 Linux kernel 2.6.26 7 Linux kernel 2.6.26 .6 Linux kernel 2.6.26 .4 Linux kernel 2.6.26 .3 Linux kernel 2.6.26 -rc6 Linux kernel 2.6.26 Linux kernel 2.6.25 19 Linux kernel 2.6.25 .9 Linux kernel 2.6.25 .8 Linux kernel 2.6.25 .7 Linux kernel 2.6.25 .6 Linux kernel 2.6.25 .5 Linux kernel 2.6.25 .15 Linux kernel 2.6.25 .13 Linux kernel 2.6.25 .12 Linux kernel 2.6.25 .11 Linux kernel 2.6.25 .10 Linux kernel 2.6.25 Linux kernel 2.6.24 .2 Linux kernel 2.6.24 .1 Linux kernel 2.6.24 -rc5 Linux kernel 2.6.24 -rc4 Linux kernel 2.6.24 -rc3 Linux kernel 2.6.24 -git13 Linux kernel 2.6.24 Linux kernel 2.6.23 .7 Linux kernel 2.6.23 .6 Linux kernel 2.6.23 .5 Linux kernel 2.6.23 .4 Linux kernel 2.6.23 .3 Linux kernel 2.6.23 .2 Linux kernel 2.6.23 -rc2 Linux kernel 2.6.23 -rc1 Linux kernel 2.6.23 Linux kernel 2.6.22 .8 Linux kernel 2.6.22 .7 Linux kernel 2.6.22 .6 Linux kernel 2.6.22 .5 Linux kernel 2.6.22 .4 Linux kernel 2.6.22 .3 Linux kernel 2.6.22 .2 Linux kernel 2.6.22 .17 Linux kernel 2.6.22 .16 Linux kernel 2.6.22 .15 Linux kernel 2.6.22 .14 Linux kernel 2.6.22 .13 Linux kernel 2.6.22 .12 Linux kernel 2.6.22 .11 Linux kernel 2.6.22 .1 Linux kernel 2.6.22 Linux kernel 2.6.21 4 Linux kernel 2.6.21 .7 Linux kernel 2.6.21 .6 Linux kernel 2.6.21 .3 Linux kernel 2.6.21 .2 Linux kernel 2.6.21 .1 Linux kernel 2.6.21 -git8 Linux kernel 2.6.21 Linux kernel 2.6.3 Linux kernel 2.6.33-rc7 Linux kernel 2.6.33-rc6-git5 Linux kernel 2.6.33-rc6 Linux kernel 2.6.33-rc5 + Trustix Secure Enterprise Linux 2.0 + Trustix Secure Linux 2.2 + Trustix Secure Linux 2.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.33-rc4 + Trustix Secure Enterprise Linux 2.0 + Trustix Secure Linux 2.2 + Trustix Secure Linux 2.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.32.8 Linux kernel 2.6.32.7 Linux kernel 2.6.32.4 Linux kernel 2.6.32.3 Linux kernel 2.6.32.12 Linux kernel 2.6.32.11 Linux kernel 2.6.32-rc8 Linux kernel 2.6.32-rc7 Linux kernel 2.6.32-rc5 Linux kernel 2.6.32-rc4 Linux kernel 2.6.32-rc3 Linux kernel 2.6.32-rc2 Linux kernel 2.6.32-rc1 Linux kernel 2.6.31.6 Linux kernel 2.6.31.4 Linux kernel 2.6.31.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.31-rc9 Linux kernel 2.6.31-rc8 + Trustix Secure Enterprise Linux 2.0 + Trustix Secure Linux 2.2 + Trustix Secure Linux 2.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.31-rc5-git3 Linux kernel 2.6.31-rc4 Linux kernel 2.6.31-rc2 Linux kernel 2.6.31-git11 + Trustix Secure Enterprise Linux 2.0 + Trustix Secure Linux 2.2 + Trustix Secure Linux 2.1 + Trustix Secure Linux 2.0 Linux kernel 2.6.30.5 Linux kernel 2.6.30.4 Linux kernel 2.6.30.3 Linux kernel 2.6.27-git3 Linux kernel 2.6.26.1 Linux kernel 2.6.26-rc5-git1 Linux kernel 2.6.25.4 Linux kernel 2.6.25.3 Linux kernel 2.6.25.2 Linux kernel 2.6.25.1 Linux kernel 2.6.25-rc1 Linux kernel 2.6.24.6 Linux kernel 2.6.24-rc2 Linux kernel 2.6.24-rc1 Linux kernel 2.6.23.14 Linux kernel 2.6.23.10 Linux kernel 2.6.23.1 Linux kernel 2.6.23.09 Linux kernel 2.6.22-rc7 Linux kernel 2.6.22-rc1 Linux kernel 2.6.21-RC6 Linux kernel 2.6.21-RC5 Linux kernel 2.6.21-RC4 Linux kernel 2.6.21-RC3

Not Vulnerable:	Linux kernel 2.6.32 .9 Linux kernel 2.6.27 .46 Linux kernel 2.6.33-rc8

Discussion

Linux Kernel 'tty_fasync()' Race Condition Null Pointer Dereference Vulnerability

The Linux kernel is prone to a null-pointer dereference vulnerability.

An attacker can exploit this issue to crash the affected system. Due to the nature of the issue, code execution is possible; however, this has not been confirmed.

Exploit / POC

Linux Kernel 'tty_fasync()' Race Condition Null Pointer Dereference Vulnerability

Currently we are not aware of any working exploits. If you feel we are in error or if you are aware of more recent information, please mail us at: [email protected].

Solution / Fix

Linux Kernel 'tty_fasync()' Race Condition Null Pointer Dereference Vulnerability

Solution:
Updates are available; please see the references for more information.

References

Linux Kernel 'tty_fasync()' Race Condition Null Pointer Dereference Vulnerability

References:

Bug 14605 - NULL Pointer Dereference drivers/char/n_tty.c (Kyle Bader)
CVE Request - kernel: put_tty_queue NULL pointer deref (dann frazier)
Fix race in tty_fasync() properly (Linus Torvalds)
Linux kernel Homepage (kernel.org)
USN-1000-1: Linux kernel vulnerabilities (Ubuntu)