7.1 - RHSA-2008:0957

Problem Description:

Updated kernel packages that resolve several security issues and fix various bugs are now available for Red Hat Enterprise Linux 5.

This update has been rated as having important security impact by the Red Hat Security Response Team.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 5 client) - i386, noarch, x86_64 Red Hat Enterprise Linux (v. 5 server) - i386, ia64, noarch, ppc, s390x, x86_64

3. Description:

The kernel packages contain the Linux kernel, the core of any Linux operating system.

* the Xen implementation did not prevent applications running in a para-virtualized guest from modifying CR4 TSC. This could cause a local denial of service. (CVE-2007-5907, Important)

* Tavis Ormandy reported missing boundary checks in the Virtual Dynamic Shared Objects (vDSO) implementation. This could allow a local unprivileged user to cause a denial of service or escalate privileges. (CVE-2008-3527, Important)

* the do_truncate() and generic_file_splice_write() functions did not clear the setuid and setgid bits. This could allow a local unprivileged user to obtain access to privileged information. (CVE-2008-4210, CVE-2008-3833, Important)

* a flaw was found in the Linux kernel splice implementation. This could cause a local denial of service when there is a certain failure in the add_to_page_cache_lru() function. (CVE-2008-4302, Important)

* a flaw was found in the Linux kernel when running on AMD64 systems. During a context switch, EFLAGS were being neither saved nor restored. This could allow a local unprivileged user to cause a denial of service. (CVE-2006-5755, Low)

* a flaw was found in the Linux kernel virtual memory implementation. This could allow a local unprivileged user to cause a denial of service. (CVE-2008-2372, Low)

* an integer overflow was discovered in the Linux kernel Datagram Congestion Control Protocol (DCCP) implementation. This could allow a remote attacker to cause a denial of service. By default, remote DCCP is blocked by SELinux. (CVE-2008-3276, Low)

In addition, these updated packages fix the following bugs:

* random32() seeding has been improved.

* in a multi-core environment, a race between the QP async event-handler and the destro_qp() function could occur. This led to unpredictable results during invalid memory access, which could lead to a kernel crash.

* a format string was omitted in the call to the request_module() function.

* a stack overflow caused by an infinite recursion bug in the binfmt_misc kernel module was corrected.

* the ata_scsi_rbuf_get() and ata_scsi_rbuf_put() functions now check for scatterlist usage before calling kmap_atomic().

* a sentinel NUL byte was added to the device_write() function to ensure that lspace.name is NUL-terminated.

* in the character device driver, a range_is_allowed() check was added to the read_mem() and write_mem() functions. It was possible for an illegitimate application to bypass these checks, and access /dev/mem beyond the 1M limit by calling mmap_mem() instead. Also, the parameters of range_is_allowed() were changed to cleanly handle greater than 32-bits of physical address on 32-bit architectures.

* some of the newer Nehalem-based systems declare their CPU DSDT entries as type "Alias". During boot, this caused an "Error attaching device data" message to be logged.

* the evtchn event channel device lacked locks and memory barriers. This has led to xenstore becoming unresponsive on the Itanium® architecture.

* sending of gratuitous ARP packets in the Xen frontend network driver is now delayed until the backend signals that its carrier status has been processed by the stack.

* on forcedeth devices, whenever setting ethtool parameters for link speed, the device could stop receiving interrupts.

* the CIFS 'forcedirectio' option did not allow text to be appended to files.

* the gettimeofday() function returned a backwards time on Intel® 64.

* residual-count corrections during UNDERRUN handling were added to the qla2xxx driver.

* the fix for a small quirk was removed for certain Adaptec controllers for which it caused problems.

* the "xm trigger init" command caused a domain panic if a userland application was running on a guest on the Intel® 64 architecture.

Users of kernel should upgrade to these updated packages, which contain backported patches to correct these issues.

4. Solution:

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

This update is available via Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at http://kbase.redhat.com/faq/FAQ_58_10188

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

377561 - CVE-2007-5907 kernel-xen 3.1.1 does not prevent modification of the CR4 TSC from applications (DoS possible) 452666 - CVE-2008-2372 kernel: Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP 457718 - CVE-2006-5755 kernel: local denial of service due to NT bit leakage 458021 - kernel: random32: seeding improvement [rhel-5.2.z] 458759 - kernel: dlm: dlm/user.c input validation fixes [rhel-5.2.z] 458781 - LTC44618-Race possibility between QP async handler and destroy_qp() 459226 - CVE-2008-3276 Linux kernel dccp_setsockopt_change() integer overflow 459461 - kernel: cpufreq: fix format string bug [rhel-5.2.z] 459464 - kernel: binfmt_misc.c: avoid potential kernel stack overflow [rhel-5.2.z] 460251 - CVE-2008-3527 kernel: missing boundary checks in syscall/syscall32_nopage() 460638 - [REG][5.3] The system crashed by the NULL pointer access with kmap_atomic() of ata_scsi_rbuf_get(). 460858 - kernel: devmem: add range_is_allowed() check to mmap_mem() [rhel-5.2.z] 460868 - RHEL5.2 ACPI core bug 461099 - evtchn device lacks lock and barriers 461457 - Coordinate gratuitous ARP with backend network status 461894 - nVidia MCP55 MCP55 Ethernet (rev a3) not functional on kernel 2.6.18-53.1.4 462434 - CVE-2008-4302 kernel: splice: fix bad unlock_page() in error case 462591 - CIFS option forcedirectio fails to allow the appending of text to files. 462860 - RHEL5.3: Fix time of gettimeofday() going backward (EM64T) (*) 463661 - CVE-2008-4210 kernel: open() call allows setgid bit when user is not in new file's group 464450 - CVE-2008-3833 kernel: remove SUID when splicing into an inode 465741 - [QLogic 5.2.z bug] qla2xxx - Additional residual-count corrections during UNDERRUN handling. 466427 - Significant regression in time() performance 466885 - [aacraid 5.2.z] aac_srb: aac_fib_send failed with status 8195 467105 - xm trigger <domain> init causes kernel panic.