Integer overflow in the hrtimer_forward function (hrtimer.c) in Linux kernel 2.6.21-rc4, when running on 64-bit systems, allows local users to cause a denial of service (infinite loop) via a timer with a large expiry value, which causes the timer to always be expired.

The remote OracleVM system is missing necessary patches to address critical security updates :

  - fix utrace dead_engine ops race

  - fix ptrace_attach leak

  - CVE-2007-5093: kernel PWC driver DoS

  - CVE-2007-6282: IPSec ESP kernel panics

  - CVE-2007-6712: kernel: infinite loop in highres timers     (kernel hang)

  - CVE-2008-1615: kernel: ptrace: Unprivileged crash on     x86_64 %cs corruption

  - CVE-2008-1294: kernel: setrlimit(RLIMIT_CPUINFO) with     zero value doesn't inherit properly across children

  - CVE-2008-2136: kernel: sit memory leak

  - CVE-2008-2812: kernel: NULL ptr dereference in multiple     network drivers due to missing checks in tty code

  - restore     linux-2.6-x86-clear-df-flag-for-signal-handlers.patch

  - restore linux-2.6-utrace.patch /     linux-2.6-xen-utrace.patch

  - Kernel security erratas for OVM 2.1.2 from bz#5932 :

  - CVE-2007-6063: isdn: fix possible isdn_net buffer     overflows

  - CVE-2007-3104 Null pointer to an inode in a dentry can     cause an oops in sysfs_readdir

  - CVE-2008-0598: write system call vulnerability

  - CVE-2008-1375: kernel: race condition in dnotify

  - CVE-2008-0001: kernel: filesystem corruption by     unprivileged user via directory truncation

  - CVE-2008-2358: dccp: sanity check feature length

  - CVE-2007-5938: NULL dereference in iwl driver

  - RHSA-2008:0508: kernel: [x86_64] The string instruction     version didn't zero the output on exception.

  - kernel: clear df flag for signal handlers

  - fs: missing dput in do_lookup error leaks dentries

  - sysfs: fix condition check in sysfs_drop_dentry

  - sysfs: fix race condition around sd->s_dentry

  - ieee80211: off-by-two integer underflow

From Red Hat Security Advisory 2008:0275 :

Updated kernel packages that fix various security issues and several 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.

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

These updated packages fix the following security issues :

* on AMD64 architectures, the possibility of a kernel crash was discovered by testing the Linux kernel process-trace ability. This could allow a local unprivileged user to cause a denial of service (kernel crash). (CVE-2008-1615, Important)

* on 64-bit architectures, the possibility of a timer-expiration value overflow was found in the Linux kernel high-resolution timers functionality, hrtimer. This could allow a local unprivileged user to setup a large interval value, forcing the timer expiry value to become negative, causing a denial of service (kernel hang). (CVE-2007-6712, Important)

* the possibility of a kernel crash was found in the Linux kernel IPsec protocol implementation, due to improper handling of fragmented ESP packets. When an attacker controlling an intermediate router fragmented these packets into very small pieces, it would cause a kernel crash on the receiving node during packet reassembly.
(CVE-2007-6282, Important)

* a potential denial of service attack was discovered in the Linux kernel PWC USB video driver. A local unprivileged user could use this flaw to bring the kernel USB subsystem into the busy-waiting state, causing a denial of service. (CVE-2007-5093, Low)

As well, these updated packages fix the following bugs :

* in certain situations, a kernel hang and a possible panic occurred when disabling the cpufreq daemon. This may have prevented system reboots from completing successfully.

* continual 'softlockup' messages, which occurred on the guest's console after a successful save and restore of a Red Hat Enterprise Linux 5 para-virtualized guest, have been resolved.

* in the previous kernel packages, the kernel may not have reclaimed NFS locks after a system reboot.

Red Hat Enterprise Linux 5 users are advised to upgrade to these updated packages, which contain backported patches to resolve these issues.

Updated kernel packages that fix various security issues and several 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.

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

These updated packages fix the following security issues :

* on AMD64 architectures, the possibility of a kernel crash was discovered by testing the Linux kernel process-trace ability. This could allow a local unprivileged user to cause a denial of service (kernel crash). (CVE-2008-1615, Important)

* on 64-bit architectures, the possibility of a timer-expiration value overflow was found in the Linux kernel high-resolution timers functionality, hrtimer. This could allow a local unprivileged user to setup a large interval value, forcing the timer expiry value to become negative, causing a denial of service (kernel hang). (CVE-2007-6712, Important)

* the possibility of a kernel crash was found in the Linux kernel IPsec protocol implementation, due to improper handling of fragmented ESP packets. When an attacker controlling an intermediate router fragmented these packets into very small pieces, it would cause a kernel crash on the receiving node during packet reassembly.
(CVE-2007-6282, Important)

* a potential denial of service attack was discovered in the Linux kernel PWC USB video driver. A local unprivileged user could use this flaw to bring the kernel USB subsystem into the busy-waiting state, causing a denial of service. (CVE-2007-5093, Low)

As well, these updated packages fix the following bugs :

* in certain situations, a kernel hang and a possible panic occurred when disabling the cpufreq daemon. This may have prevented system reboots from completing successfully.

* continual 'softlockup' messages, which occurred on the guest's console after a successful save and restore of a Red Hat Enterprise Linux 5 para-virtualized guest, have been resolved.

* in the previous kernel packages, the kernel may not have reclaimed NFS locks after a system reboot.

Red Hat Enterprise Linux 5 users are advised to upgrade to these updated packages, which contain backported patches to resolve these issues.

Dirk Nehring discovered that the IPsec protocol stack did not correctly handle fragmented ESP packets. A remote attacker could exploit this to crash the system, leading to a denial of service.
(CVE-2007-6282)

Johannes Bauer discovered that the 64bit kernel did not correctly handle hrtimer updates. A local attacker could request a large expiration value and cause the system to hang, leading to a denial of service. (CVE-2007-6712)

Tavis Ormandy discovered that the ia32 emulation under 64bit kernels did not fully clear uninitialized data. A local attacker could read private kernel memory, leading to a loss of privacy. (CVE-2008-0598)

Jan Kratochvil discovered that PTRACE did not correctly handle certain calls when running under 64bit kernels. A local attacker could exploit this to crash the system, leading to a denial of service.
(CVE-2008-1615)

Wei Wang discovered that the ASN.1 decoding routines in CIFS and SNMP NAT did not correctly handle certain length values. Remote attackers could exploit this to execute arbitrary code or crash the system.
(CVE-2008-1673)

Paul Marks discovered that the SIT interfaces did not correctly manage allocated memory. A remote attacker could exploit this to fill all available memory, leading to a denial of service. (CVE-2008-2136)

David Miller and Jan Lieskovsky discovered that the Sparc kernel did not correctly range-check memory regions allocated with mmap. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2008-2137)

The sys_utimensat system call did not correctly check file permissions in certain situations. A local attacker could exploit this to modify the file times of arbitrary files which could lead to a denial of service. (CVE-2008-2148)

Brandon Edwards discovered that the DCCP system in the kernel did not correctly check feature lengths. A remote attacker could exploit this to execute arbitrary code. (CVE-2008-2358)

A race condition was discovered between ptrace and utrace in the kernel. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2008-2365)

The copy_to_user routine in the kernel did not correctly clear memory destination addresses when running on 64bit kernels. A local attacker could exploit this to gain access to sensitive kernel memory, leading to a loss of privacy. (CVE-2008-2729)

The PPP over L2TP routines in the kernel did not correctly handle certain messages. A remote attacker could send a specially crafted packet that could crash the system or execute arbitrary code.
(CVE-2008-2750)

Gabriel Campana discovered that SCTP routines did not correctly check for large addresses. A local user could exploit this to allocate all available memory, leading to a denial of service. (CVE-2008-2826).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This kernel update fixes the following security problems :

CVE-2008-1615: On x86_64 a denial of service attack could be used by local attackers to immediately panic / crash the machine.

CVE-2008-2358: A security problem in DCCP was fixed, which could be used by remote attackers to crash the machine.

CVE-2007-6206: An information leakage during coredumping of root processes was fixed.

CVE-2007-6712: A integer overflow in the hrtimer_forward function (hrtimer.c) in Linux kernel, when running on 64-bit systems, allows local users to cause a denial of service (infinite loop) via a timer with a large expiry value, which causes the timer to always be expired.

CVE-2008-2136: A problem in SIT IPv6 tunnel handling could be used by remote attackers to immediately crash the machine.

CVE-2008-1669: Fixed a SMP ordering problem in fcntl_setlk could potentially allow local attackers to execute code by timing file locking.

CVE-2008-1367: Clear the 'direction' flag before calling signal handlers. For specific not yet identified programs under specific timing conditions this could potentially have caused memory corruption or code execution.

CVE-2008-1375: Fixed a dnotify race condition, which could be used by local attackers to potentially execute code.

CVE-2007-6282: A remote attacker could crash the IPSec/IPv6 stack by sending a bad ESP packet. This requires the host to be able to receive such packets (default filtered by the firewall).

CVE-2007-5500: A ptrace bug could be used by local attackers to hang their own processes indefinitely.

CVE-2007-5904: A remote buffer overflow in CIFS was fixed which could be used by remote attackers to crash the machine or potentially execute code.

And the following bugs (numbers are https://bugzilla.novell.com/ references) :

  - patches.arch/x86-nosmp-implies-noapic.patch: When     booting with nosmp or maxcpus=0 on i386 or x86-64, we     must disable the I/O APIC, otherwise the system won't     boot in most cases (bnc#308540).

  - patches.arch/i386-at-sysinfo-ehdr: i386: make     AT_SYSINFO_EHDR consistent with AT_SYSINFO (bnc#289641).

  - patches.suse/bonding-workqueue: Update to fix a hang     when closing a bonding device (342994).

  - patches.fixes/mptspi-dv-renegotiate-oops: mptlinux     crashes on kernel 2.6.22 (bnc#271749).

Several vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2007-6712     Johannes Bauer discovered an integer overflow condition     in the hrtimer subsystem on 64-bit systems. This can be     exploited by local users to trigger a denial of service     (DoS) by causing the kernel to execute an infinite loop.

  - CVE-2008-1615     Jan Kratochvil reported a local denial of service     condition that permits local users on systems running     the amd64 flavor kernel to cause a system crash.

  - CVE-2008-2136     Paul Harks discovered a memory leak in the Simple     Internet Transition (SIT) code used for IPv6 over IPv4     tunnels. This can be exploited by remote users to cause     a denial of service condition.

  - CVE-2008-2137     David Miller and Jan Lieskovsky discovered issues with     the virtual address range checking of mmaped regions on     the sparc architecture that may be exploited by local     users to cause a denial of service.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2008-0275.

ID	Name	Product	Family	Severity
79447	OracleVM 2.1 : kernel (OVMSA-2008-2005)	Nessus	OracleVM Local Security Checks	high
67691	Oracle Linux 5 : kernel (ELSA-2008-0275)	Nessus	Oracle Linux Local Security Checks	high
43685	CentOS 5 : kernel (CESA-2008:0275)	Nessus	CentOS Local Security Checks	high
33531	Ubuntu 6.06 LTS / 7.04 / 7.10 / 8.04 LTS : linux, linux-source-2.6.15/20/22 vulnerabilities (USN-625-1)	Nessus	Ubuntu Local Security Checks	critical
33252	openSUSE 10 Security Update : kernel (kernel-5336)	Nessus	SuSE Local Security Checks	high
32448	Debian DSA-1588-1 : linux-2.6 - denial of service	Nessus	Debian Local Security Checks	high
32391	RHEL 5 : kernel (RHSA-2008:0275)	Nessus	Red Hat Local Security Checks	high
801452	CentOS RHSA-2008-0275 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2007-6712

medium

Tenable Plugins

high

high

high

critical

high

high

high

high