USN-38-1: Linux kernel vulnerabilities
15 December 2004
Linux kernel vulnerabilities
Vitaly V. Bursov discovered a Denial of Service vulnerability in the "serio"
code; opening the same tty device twice and doing some particular operations on
it caused a kernel panic and/or a system lockup.
Fixing this vulnerability required a change in the Application Binary
Interface (ABI) of the kernel. This means that third party user installed
modules might not work any more with the new kernel, so this fixed kernel got
a new ABI version number. You have to recompile and reinstall all third party
Paul Starzetz discovered a buffer overflow vulnerability in the "__scm_send"
function which handles the sending of UDP network packets. A wrong validity
check of the cmsghdr structure allowed a local attacker to modify kernel
memory, thus causing an endless loop (Denial of Service) or possibly even
root privilege escalation.
Thomas Hellström discovered a Denial of Service vulnerability in the Direct
Rendering Manager (DRM) drivers. Due to an insufficient DMA lock checking,
any authorized client could send arbitrary values to the video card, which
could cause an X server crash or modification of the video output.
Rob Landley discovered a race condition in the handling of /proc/.../cmdline.
Under very rare circumstances an user could read the environment variables of
another process that was still spawning. Environment variables are often used
to pass passwords and other private information to other processes.
A race condition was discovered in the handling of AF_UNIX network packets.
This reportedly allowed local users to modify arbitrary kernel memory,
facilitating privilege escalation, or possibly allowing code execution in the
context of the kernel.
Ross Kendall Axe discovered a possible kernel panic (causing a Denial of
Service) while sending AF_UNIX network packages if the kernel options
CONFIG_SECURITY_NETWORK and CONFIG_SECURITY_SELINUX are enabled. This is not
the case in the kernel packages shipped in Warty Warthog; however, if you
recompiled the kernel using SELinux, you are affected by this flaw.
Paul Starzetz discovered several flaws in the IGMP handling code. This
allowed users to provoke a Denial of Service, read kernel memory, and execute
arbitrary code with root privileges. This flaw is also exploitable remotely
if an application has bound a multicast socket.
Jeremy Fitzhardinge discovered two buffer overflows in the sys32_ni_syscall()
and sys32_vm86_warning() functions. This could possibly be exploited to
overwrite kernel memory with attacker-supplied code and cause root privilege
This vulnerability only affects the amd64 architecture.
The problem can be corrected by updating your system to the following package versions:
In general, a standard system update will make all the necessary changes.