oss-security - CVE-2008-3832 kernel: null pointer dereference in utrace

Openwall Project		/home Owl JtR Pro crypt pam_passwdqc tcb phpass scanlogd popa3d msulogin / Linux BIND / advisories presentations / services donations / wordlists passwords / news community lists wiki CVSweb mirrors signatures
bringing security into open environments

Password Recovery Resources on the Net

[<prev] [next>] [month] [year] [list]

Date: Thu, 02 Oct 2008 09:22:54 +0800
From: Eugene Teo <eteo@...hat.com>
To: oss-security@...ts.openwall.com
Subject: CVE-2008-3832 kernel: null pointer dereference in utrace_control

Michael Simms reported that it is possible for an unprivileged user to
crash the machine by running gdb on a running process with pid 1.

This affects the version of utrace as shipped with Fedora 8 and 9. This
is addressed in kernel-2.6.26.5-28 for Fedora 8, and kernel-2.6.26.5-45
for Fedora 9. This issue is specific to Fedora, and does not affect
upstream or any of the Red Hat Enterprise Linux kernels.

References:
http://kerneloops.org/oops.php?number=56705
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2008-3832

Thanks, Eugene
-- 
Eugene Teo / Red Hat Security Response Team

Index: linux-2.6-utrace.patch
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/F-9/linux-2.6-utrace.patch,v
retrieving revision 1.78
retrieving revision 1.79
diff -u -b -p -r1.78 -r1.79
--- linux-2.6-utrace.patch	4 Aug 2008 22:20:04 -0000	1.78
+++ linux-2.6-utrace.patch	15 Sep 2008 23:50:37 -0000	1.79
@@ -1994,7 +1994,7 @@ index ef66127..dcf30f5 100644  
 +	if (IS_ERR(engine))
 +		return engine;
 +	if (likely(!ptrace_update_utrace(child, engine)))
-+		return 0;
++		return engine;
 +	ptrace_detach_utrace(child, engine);
 +	return ERR_PTR(-ESRCH);
 +}

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.