USN-395-1: Linux kernel vulnerabilities

14 December 2006

Linux kernel vulnerabilities

Releases

Details

Mark Dowd discovered that the netfilter iptables module did not
correcly handle fragmented packets. By sending specially crafted
packets, a remote attacker could exploit this to bypass firewall
rules. This has only be fixed for Ubuntu 6.10; the corresponding fix
for Ubuntu 5.10 and 6.06 will follow soon. (CVE-2006-4572)

Dmitriy Monakhov discovered an information leak in the
__block_prepare_write() function. During error recovery, this function
did not properly clear memory buffers which could allow local users to
read portions of unlinked files. This only affects Ubuntu 5.10.
(CVE-2006-4813)

ADLab Venustech Info Ltd discovered that the ATM network driver
referenced an already released pointer in some circumstances. By
sending specially crafted packets to a host over ATM, a remote
attacker could exploit this to crash that host. This does not affect
Ubuntu 6.10. (CVE-2006-4997)

Matthias Andree discovered that the NFS locking management daemon
(lockd) did not correctly handle mixing of 'lock' and 'nolock' option
mounts on the same client. A remote attacker could exploit this to
crash lockd and thus rendering the NFS imports inaccessible. This only
affects Ubuntu 5.10. (CVE-2006-5158)

The task switching code did not save and restore EFLAGS of processes.
By starting a specially crafted executable, a local attacker could
exploit this to eventually crash many other running processes. This
does not affect Ubuntu 6.10. (CVE-2006-5173)

James Morris discovered that the ip6fl_get_n() function incorrectly
handled flow labels. A local attacker could exploit this to crash the
kernel. (CVE-2006-5619)

Fabio Massimo Di Nitto discovered that the sys_get_robust_list and
sys_set_robust_list system calls lacked proper lock handling on the
powerpc platform. A local attacker could exploit this to create
unkillable processes, drain all available CPU/memory, and render the
machine unrebootable. This only affects Ubuntu 6.10. (CVE-2006-5648)

Fabio Massimo Di Nitto discovered a flaw in the alignment check
exception handling on the powerpc platform. A local attacker could
exploit this to cause a kernel panic and crash the machine.
(CVE-2006-5649)

Certain corrupted squashfs file system images caused a memory
allocation to be freed twice. By mounting a specially crafted squashfs
file system, a local attacker could exploit this to crash the kernel.
This does not affect Ubuntu 5.10. (CVE-2006-5701)

An integer overflow was found in the get_fdb_entries() function of the
network bridging code. By executing a specially crafted ioctl, a local
attacker could exploit this to execute arbitrary code with root
privileges. (CVE-2006-5751)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 6.10
  • linux-image-2.6.17-10-386 - 2.6.17.1-10.34
  • linux-image-2.6.17-10-generic - 2.6.17.1-10.34
  • linux-image-2.6.17-10-powerpc - 2.6.17.1-10.34
  • linux-image-2.6.17-10-powerpc-smp - 2.6.17.1-10.34
  • linux-image-2.6.17-10-powerpc64-smp - 2.6.17.1-10.34
  • linux-image-2.6.17-10-server - 2.6.17.1-10.34
  • linux-image-2.6.17-10-server-bigiron - 2.6.17.1-10.34
  • linux-image-2.6.17-10-sparc64 - 2.6.17.1-10.34
  • linux-image-2.6.17-10-sparc64-smp - 2.6.17.1-10.34
Ubuntu 6.06
  • linux-image-2.6.15-27-386 - 2.6.15-27.50
  • linux-image-2.6.15-27-686 - 2.6.15-27.50
  • linux-image-2.6.15-27-amd64-generic - 2.6.15-27.50
  • linux-image-2.6.15-27-amd64-k8 - 2.6.15-27.50
  • linux-image-2.6.15-27-amd64-server - 2.6.15-27.50
  • linux-image-2.6.15-27-amd64-xeon - 2.6.15-27.50
  • linux-image-2.6.15-27-k7 - 2.6.15-27.50
  • linux-image-2.6.15-27-powerpc - 2.6.15-27.50
  • linux-image-2.6.15-27-powerpc-smp - 2.6.15-27.50
  • linux-image-2.6.15-27-powerpc64-smp - 2.6.15-27.50
  • linux-image-2.6.15-27-server - 2.6.15-27.50
  • linux-image-2.6.15-27-server-bigiron - 2.6.15-27.50
  • linux-image-2.6.15-27-sparc64 - 2.6.15-27.50
  • linux-image-2.6.15-27-sparc64-smp - 2.6.15-27.50
  • linux-source-2.6.15 - 2.6.15-27.50
Ubuntu 5.10
  • linux-image-2.6.12-10-386 - 2.6.12-10.42
  • linux-image-2.6.12-10-686 - 2.6.12-10.42
  • linux-image-2.6.12-10-686-smp - 2.6.12-10.42
  • linux-image-2.6.12-10-amd64-generic - 2.6.12-10.42
  • linux-image-2.6.12-10-amd64-k8 - 2.6.12-10.42
  • linux-image-2.6.12-10-amd64-k8-smp - 2.6.12-10.42
  • linux-image-2.6.12-10-amd64-xeon - 2.6.12-10.42
  • linux-image-2.6.12-10-k7 - 2.6.12-10.42
  • linux-image-2.6.12-10-k7-smp - 2.6.12-10.42
  • linux-image-2.6.12-10-powerpc - 2.6.12-10.42
  • linux-image-2.6.12-10-powerpc-smp - 2.6.12-10.42
  • linux-image-2.6.12-10-powerpc64-smp - 2.6.12-10.42
  • linux-image-2.6.12-10-sparc64 - 2.6.12-10.42
  • linux-image-2.6.12-10-sparc64-smp - 2.6.12-10.42
  • linux-patch-ubuntu-2.6.12 - 2.6.12-10.42

After a standard system upgrade you need to reboot your computer to
effect the necessary changes.

Related notices

  • USN-416-1: linux-image-2.6.12-10-amd64-k8-smp, linux-image-2.6.17-11-powerpc-smp, linux-image-2.6.15-28-386, linux-image-2.6.15-28-server-bigiron, linux-image-2.6.17-11-server-bigiron, linux-image-2.6.17-11-powerpc64-smp, linux-image-2.6.15-28-powerpc, linux-image-2.6.15-28-server, linux-image-2.6.17-11-sparc64-smp, linux-image-2.6.12-10-k7, linux-patch-ubuntu-2.6.12, linux-image-2.6.15-28-amd64-server, linux-image-2.6.12-10-amd64-k8, linux-image-2.6.15-28-amd64-generic, linux-image-2.6.15-28-powerpc-smp, linux-image-2.6.17-11-sparc64, linux-image-2.6.12-10-686, linux-image-2.6.12-10-powerpc64-smp, linux-image-2.6.15-28-686, linux-image-2.6.12-10-686-smp, linux-image-2.6.12-10-powerpc, linux-image-2.6.12-10-386, linux-image-2.6.15-28-sparc64-smp, linux-image-2.6.15-28-powerpc64-smp, linux-image-2.6.15-28-amd64-k8, linux-image-2.6.17-11-386, linux-image-2.6.17-11-server, linux-image-2.6.17-11-powerpc, linux-image-2.6.12-10-powerpc-smp, linux-image-2.6.15-28-sparc64, linux-image-2.6.17-11-generic, linux-image-2.6.12-10-amd64-generic, linux-image-2.6.15-28-k7, linux-image-2.6.12-10-k7-smp, linux-image-2.6.15-28-amd64-xeon, linux-image-2.6.12-10-amd64-xeon