7.2 - RHSA-2013:0744

Problem Description:

Updated kernel packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - noarch, x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

Security:

* An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way the Intel i915 driver in the Linux kernel handled the allocation of the buffer used for relocation copies. A local user with console access could use this flaw to cause a denial of service or escalate their privileges. (CVE-2013-0913, Important)

* A buffer overflow flaw was found in the way UTF-8 characters were converted to UTF-16 in the utf8s_to_utf16s() function of the Linux kernel's FAT file system implementation. A local user able to mount a FAT file system with the "utf8=1" option could use this flaw to crash the system or, potentially, to escalate their privileges. (CVE-2013-1773, Important)

* A flaw was found in the way KVM handled guest time updates when the buffer the guest registered by writing to the MSR_KVM_SYSTEM_TIME machine state register (MSR) crossed a page boundary. A privileged guest user could use this flaw to crash the host or, potentially, escalate their privileges, allowing them to execute arbitrary code at the host kernel level. (CVE-2013-1796, Important)

* A potential use-after-free flaw was found in the way KVM handled guest time updates when the GPA (guest physical address) the guest registered by writing to the MSR_KVM_SYSTEM_TIME machine state register (MSR) fell into a movable or removable memory region of the hosting user-space process (by default, QEMU-KVM) on the host. If that memory region is deregistered from KVM using KVM_SET_USER_MEMORY_REGION and the allocated virtual memory reused, a privileged guest user could potentially use this flaw to escalate their privileges on the host. (CVE-2013-1797, Important)

* A flaw was found in the way KVM emulated IOAPIC (I/O Advanced Programmable Interrupt Controller). A missing validation check in the ioapic_read_indirect() function could allow a privileged guest user to crash the host, or read a substantial portion of host kernel memory. (CVE-2013-1798, Important)

* A race condition in install_user_keyrings(), leading to a NULL pointer dereference, was found in the key management facility. A local, unprivileged user could use this flaw to cause a denial of service. (CVE-2013-1792, Moderate)

* A NULL pointer dereference in the XFRM implementation could allow a local user who has the CAP_NET_ADMIN capability to cause a denial of service. (CVE-2013-1826, Moderate)

* A NULL pointer dereference in the Datagram Congestion Control Protocol (DCCP) implementation could allow a local user to cause a denial of service. (CVE-2013-1827, Moderate)

* Information leak flaws in the XFRM implementation could allow a local user who has the CAP_NET_ADMIN capability to leak kernel stack memory to user-space. (CVE-2012-6537, Low)

* Two information leak flaws in the Asynchronous Transfer Mode (ATM) subsystem could allow a local, unprivileged user to leak kernel stack memory to user-space. (CVE-2012-6546, Low)

* An information leak was found in the TUN/TAP device driver in the networking implementation. A local user with access to a TUN/TAP virtual interface could use this flaw to leak kernel stack memory to user-space. (CVE-2012-6547, Low)

* An information leak in the Bluetooth implementation could allow a local user who has the CAP_NET_ADMIN capability to leak kernel stack memory to user-space. (CVE-2013-0349, Low)

* A use-after-free flaw was found in the tmpfs implementation. A local user able to mount and unmount a tmpfs file system could use this flaw to cause a denial of service or, potentially, escalate their privileges. (CVE-2013-1767, Low)

* A NULL pointer dereference was found in the Linux kernel's USB Inside Out Edgeport Serial Driver implementation. An attacker with physical access to a system could use this flaw to cause a denial of service. (CVE-2013-1774, Low)

Red Hat would like to thank Andrew Honig of Google for reporting CVE-2013-1796, CVE-2013-1797, and CVE-2013-1798. CVE-2013-1792 was discovered by Mateusz Guzik of Red Hat EMEA GSS SEG Team.

4. Solution:

This update also fixes several bugs. Documentation for these changes will be available shortly from the Technical Notes document linked to in the References section.

Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/knowledge/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not use "rpm -Uvh" as that will remove the running kernel binaries from your system. You may use "rpm -e" to remove old kernels after determining that the new kernel functions properly on your system.

5. Bugs fixed (http://bugzilla.redhat.com/):

914298 - CVE-2013-0349 kernel: bluetooth HIDP implementation information disclosure 915592 - CVE-2013-1767 Kernel: tmpfs: fix use-after-free of mempolicy object 916115 - CVE-2013-1773 kernel: VFAT slab-based buffer overflow 916191 - CVE-2013-1774 Kernel: USB io_ti driver NULL pointer dereference in routine chase_port 916646 - CVE-2013-1792 Kernel: keys: race condition in install_user_keyrings() 917012 - CVE-2013-1796 kernel: kvm: buffer overflow in handling of MSR_KVM_SYSTEM_TIME 917013 - CVE-2013-1797 kernel: kvm: after free issue with the handling of MSR_KVM_SYSTEM_TIME 917017 - CVE-2013-1798 kernel: kvm: out-of-bounds access in ioapic indirect register reads 919164 - CVE-2013-1827 Kernel: dccp: check ccid before NULL poiter dereference 919384 - CVE-2013-1826 Kernel: xfrm_user: return error pointer instead of NULL 920471 - CVE-2013-0913 Kernel: drm/i915: heap writing overflow 922344 - CVE-2012-6547 Kernel: net/tun: ioctl() based information leaks 922383 - CVE-2012-6546 Kernel: atm: information leak in getsockopt & getsockname 922424 - CVE-2012-6537 Kernel: xfrm_user information leaks copy_to_user_