Updated kernel-rt packages that fix several security issues, multiple bugs, and add enhancements are now available for Red Hat Enterprise MRG 1.1. This update has been rated as having important security impact by the Red Hat Security Response Team.
The kernel-rt packages contain the Linux kernel, the core of any Linux operating system. Security fixes: * the ADDR_COMPAT_LAYOUT and MMAP_PAGE_ZERO flags were not cleared when a setuid or setgid program was executed. A local, unprivileged user could use this flaw to bypass the mmap_min_addr protection mechanism and perform a NULL pointer dereference attack, or bypass the Address Space Layout Randomization (ASLR) security feature. (CVE-2009-1895, Important) * a system with SELinux enforced was more permissive in allowing local users in the unconfined_t domain to map low memory areas even if the mmap_min_addr restriction was enabled. This could aid in the local exploitation of NULL pointer dereference bugs. (CVE-2009-2695, Important) * missing initialization flaws were found in getname() implementations in numerous network protocol implementations in the Linux kernel. Certain data structures in these getname() implementations were not initialized properly before being copied to user-space. These flaws could lead to an information leak. (CVE-2009-3002, Important) * a NULL pointer dereference flaw was found in each of the following functions in the Linux kernel: pipe_read_open(), pipe_write_open(), and pipe_rdwr_open(). When the mutex lock is not held, the i_pipe pointer could be released by other processes before it is used to update the pipe's reader and writer counters. This could lead to a local denial of service or privilege escalation. (CVE-2009-3547, Important) * a flaw was found in the Realtek r8169 Ethernet driver in the Linux kernel. pci_unmap_single() presented a memory leak that could lead to IOMMU space exhaustion and a system crash. An attacker on the local network could abuse this flaw by using jumbo frames for large amounts of network traffic. (CVE-2009-3613, Important) * NULL pointer dereference flaws were found in the r128 driver in the Linux kernel. Checks to test if the Concurrent Command Engine state was initialized were missing in private IOCTL functions. An attacker could use these flaws to cause a local denial of service or escalate their privileges. (CVE-2009-3620, Important) * Kees Cook and Steve Beattie discovered a race condition in the /proc code in the Linux kernel. This could lead to information in the "/proc/[pid]/maps" and "/proc/[pid]/smaps" files being leaked to users (who would otherwise not have access to this information) during ELF loading. This could help a local attacker bypass the ASLR security feature. (CVE-2009-2691, Moderate) * a NULL pointer dereference flaw was found in the md driver in the Linux kernel. If the suspend_lo or suspend_hi file in "/sys/" is modified when the disk array is inactive, it could lead to a local denial of service or privilege escalation. By default, only root can write to these two files. (CVE-2009-2849, Moderate) * an information leak was found in the Linux kernel. On AMD64 systems, 32-bit processes could access and read certain 64-bit registers by temporarily switching themselves to 64-bit mode. (CVE-2009-2910, Moderate) * padding data in several core network structures was not initialized properly before being sent to user-space, possibly leading to information leaks. (CVE-2009-3228, CVE-2009-3612, Moderate) * the unix_stream_connect() function in the Linux kernel did not check if a UNIX domain socket was in the shutdown state. This could lead to a deadlock. A local, unprivileged user could use this flaw to cause a denial of service. (CVE-2009-3621, Moderate) These updated packages also include bug fixes and enhancements. Users are directed to the Realtime Security Update Release Notes for version 1.1 for information on these changes, which will be available shortly from: http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/ Users should upgrade to these updated packages, which contain backported patches to correct these issues and add enhancements. The system must be rebooted for this update to take effect.