DESCRIPTION
The Linux kernel is responsible for handling the basic functions of
the GNU/Linux operating system.
This announcement fixes the following vulnerabilities:
1. Integer overflow in netfilter's tcp_find_option function
(CAN-2004-0626[1])
Adam Osuchowski and Tomasz Dubinski noticed[2] that when using
iptables and TCP options rules, the tcp_find_option function of the
netfilter subsystem in Linux kernel 2.6 allows remote attackers to
cause a denial of service via a large option length that produces a
negative integer after a casting operation to the char type. They
also provided the corretion for this bug.
2. Missing DAC check's in inode_change_ok function
(CAN-2004-0497[3])
Missing Discretionary Access Control (DAC) checks in chown system
call allowed a local user to change the group ownership of arbitrary
files to a group that he or she belongs to, leading to a privileges
escalation vulnerability.
3. Integer overflow in ip_setsockopt function (CAN-2004-0424[4])
iSEC Security Research published[5] an integer overflow
vulnerability[4] in the ip_setsockopt function on Linux kernel 2.6.1
through 2.6.3 which allows local users to cause a denial of service
condition or execute arbitrary code via the MCAST_MSFILTER socket
option.
4. Incorrect usage of the fb_copy_cmap function in framebuffer
(CAN-2004-0229[6])
The framebuffer driver in Linux kernel 2.6.x did not properly use the
fb_copy_cmap function, possibly allowing privileges escalation for
local attackers.
5. Integer overflow in the cpufreq proc handler (CAN-2004-0228[7])
Brad Spender found an integer overflow bug in the Linux kernel
cpufreq code that allowed a local attacker to read arbitrary kernel
memory.
SOLUTION
It is recommended that all Conectiva Linux users upgrade the kernel
package.
IMPORTANT: exercise caution and preparation when upgrading the
kernel, since it will require a reboot after the new packages are
installed. In particular, Conectiva Linux 10 will most likely require
an initrd file (which is automatically created in the /boot directory
after the new packages are installed) and by default a new grub entry
will be added, not touching the old default option. Generic kernel
update instructions can be obtained in the manuals and in our
frequently asked questions page[8].
