Linux kernel before 2.6.16.5 does not properly handle uncanonical return addresses on Intel EM64T CPUs, which reports an exception in the SYSRET instead of the next instruction, which causes the kernel exception handler to run on the user stack with the wrong GS.

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

  - x86-64: detect processors subject to AMD erratum #121     and refuse to boot(CVE-2006-0744)

  - guest denial of service on syscall/sysenter exception     generation (CVE-2012-0217),(CVE-2012-0218)

  - Remove unnecessary balloon retries on vm create. This is     a backport from fix for bug 14143327.

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

  - x86-64: detect processors subject to AMD erratum #121     and refuse to boot(CVE-2006-0744)

  - guest denial of service on syscall/sysenter exception     generation (CVE-2012-0217)

  - Remove unnecessary balloon retries on vm create. This is     a backport from fix for bug 14143327.

  - This backport from 3.1.1: Author: amisherf Put back the     patch that prevent older guest that uses kudzu from     hanging on a reboot. Fixed the patch to prevent     excessive watcher writes which causes xend, xenstored to     run at a 100% cpu usage. Now the watch is written only     if console in Initialising, InitWait, Initialised states     which happen once at boot time. [bug 13523487]

  - Backport from upstream changeset 20968 xend: notify     xenpv device model that console info is ready Sometimes     PV domain with vfb doesn't boot up. /sbin/kudzu is     stuck. After investigation, I've found that the evtchn     for console is not bound at all. Normal sequence of     evtchn initialization in qemu-dm for xenpv is: 1) watch     xenstore backpath     (/local/domain/0/backend/console/<domid>/0) 2) read     console info (/local/domain/<domid>/console/[type,     ring-ref, port..= ]) 3) bind the evtchn to the port. But     in some case, xend writes to the backpath before the     console info is prepared, and never write to the     backpath again. So the qemu-dm fails at 2) and never     reach to 3). When this happens, manually xenstore-write     command on Domain-0 resumes the guest.

  - Set max cstate to 1. This is a backport requirement for     bug 13703504. We have several bugs that cstate made     system unstable, both for ovm2 and ovm3: For OVM3.x: Bug     13703504 - unexplained network disconnect causes ocfs to     fence the server For OVM2.x

An integer overflow was discovered in the do_replace() function. A local user process with the CAP_NET_ADMIN capability could exploit this to execute arbitrary commands with full root privileges. However, none of Ubuntu's supported packages use this capability with any non-root user, so this only affects you if you use some third party software like the OpenVZ virtualization system. (CVE-2006-0038)

On EMT64 CPUs, the kernel did not properly handle uncanonical return addresses. A local user could exploit this to trigger a kernel crash.
(CVE-2006-0744)

Al Viro discovered a local Denial of Service in the sysfs write buffer handling. By writing a block with a length exactly equal to the processor's page size to any writable file in /sys, a local attacker could cause a kernel crash. (CVE-2006-1055)

Jan Beulich discovered an information leak in the handling of registers for the numeric coprocessor when running on AMD processors.
This allowed processes to see the coprocessor execution state of other processes, which could reveal sensitive data in the case of cryptographic computations. (CVE-2006-1056)

Marcel Holtmann discovered that the sys_add_key() did not check that a new user key is added to a proper keyring. By attempting to add a key to a normal user key (which is not a keyring), a local attacker could exploit this to crash the kernel. (CVE-2006-1522)

Ingo Molnar discovered that the SCTP protocol connection tracking module in netfilter got stuck in an infinite loop on certain empty packet chunks. A remote attacker could exploit this to cause the computer to hang. (CVE-2006-1527)

The SCSI I/O driver did not correctly handle the VM_IO flag for memory mapped pages used for data transfer. A local user could exploit this to cause a kernel crash. (CVE-2006-1528)

The choose_new_parent() contained obsolete debugging code. A local user could exploit this to cause a kernel crash. (CVE-2006-1855)

Kostik Belousov discovered that the readv() and writev() functions did not query LSM modules for access permission. This could be exploited to circumvent access restrictions defined by LSM modules such as SELinux or AppArmor. (CVE-2006-1856)

The SCTP driver did not properly verify certain parameters when receiving a HB-ACK chunk. By sending a specially crafted packet to an SCTP socket, a remote attacker could exploit this to trigger a buffer overflow, which could lead to a crash or possibly even arbitrary code execution. (CVE-2006-1857)

The sctp_walk_params() function in the SCTP driver incorrectly used rounded values for bounds checking instead of the precise values. By sending a specially crafted packet to an SCTP socket, a remote attacker could exploit this to crash the kernel. (CVE-2006-1858)

Bjoern Steinbrink reported a memory leak in the __setlease() function.
A local attacker could exploit this to exhaust kernel memory and render the computer unusable (Denial of Service). (CVE-2006-1859)

Daniel Hokka Zakrisson discovered that the lease_init() did not properly handle locking. A local attacker could exploit this to cause a kernel deadlock (Denial of Service). (CVE-2006-1860)

Mark Moseley discovered that the CIFS file system driver did not filter out '..\\' path components. A local attacker could exploit this to break out of a chroot environment on a mounted SMB share.
(CVE-2006-1863) The same vulnerability applies to the older smb file system. (CVE-2006-1864)

Hugh Dickins discovered that the mprotect() function allowed an user to change a read-only shared memory attachment to become writable, which bypasses IPC (inter-process communication) permissions.
(CVE-2006-2071)

The SCTP (Stream Control Transmission Protocol) driver triggered a kernel panic on unexpected packets while the session was in the CLOSED state, instead of silently ignoring the packets. A remote attacker could exploit this to crash the computer. (CVE-2006-2271)

The SCTP driver did not handle control chunks if they arrived in fragmented packets. By sending specially crafted packets to an SCTP socket, a remote attacker could exploit this to crash the target machine. (CVE-2006-2272)

The SCTP driver did not correctly handle packets containing more than one DATA fragment. By sending specially crafted packets to an SCTP socket, a remote attacker could exploit this to crash the target machine. (CVE-2006-2274)

The SCTP driver did not correcly buffer incoming packets. By sending a large number of small messages to a receiver application that cannot process the messages quickly enough, a remote attacker could exploit this to cause a deadlock in the target machine (Denial of Service).
(CVE-2006-2275)

Patrick McHardy discovered that the snmp_trap_decode() function did not correctly handle memory allocation in some error conditions. By sending specially crafted packets to a machine which uses the SNMP network address translation (NAT), a remote attacker could exploit this to crash that machine. (CVE-2006-2444)

In addition, the Ubuntu 6.06 LTS update fixes a range of bugs.

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.

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

  - CVE-2005-3359     Franz Filz discovered that some socket calls permit     causing inconsistent reference counts on loadable     modules, which allows local users to cause a denial of     service.

  - CVE-2006-0038     'Solar Designer' discovered that arithmetic computations     in netfilter's do_replace() function can lead to a     buffer overflow and the execution of arbitrary code.
    However, the operation requires CAP_NET_ADMIN     privileges, which is only an issue in virtualization     systems or fine grained access control systems.

  - CVE-2006-0039     'Solar Designer' discovered a race condition in     netfilter's do_add_counters() function, which allows     information disclosure of kernel memory by exploiting a     race condition. Likewise, it requires CAP_NET_ADMIN     privileges. 

  - CVE-2006-0456     David Howells discovered that the s390 assembly version     of the strnlen_user() function incorrectly returns some     string size values.

  - CVE-2006-0554     It was discovered that the ftruncate() function of XFS     can expose unallocated blocks, which allows information     disclosure of previously deleted files.

  - CVE-2006-0555     It was discovered that some NFS file operations on     handles mounted with O_DIRECT can force the kernel into     a crash.

  - CVE-2006-0557     It was discovered that the code to configure memory     policies allows tricking the kernel into a crash, thus     allowing denial of service.

  - CVE-2006-0558     It was discovered by Cliff Wickman that perfmon for the     IA64 architecture allows users to trigger a BUG()     assert, which allows denial of service.

  - CVE-2006-0741     Intel EM64T systems were discovered to be susceptible to     a local DoS due to an endless recursive fault related to     a bad ELF entry address.

  - CVE-2006-0742     Alan and Gareth discovered that the ia64 platform had an     incorrectly declared die_if_kernel() function as 'does     never return' which could be exploited by a local     attacker resulting in a kernel crash.

  - CVE-2006-0744     The Linux kernel did not properly handle uncanonical     return addresses on Intel EM64T CPUs, reporting     exceptions in the SYSRET instead of the next     instruction, causing the kernel exception handler to run     on the user stack with the wrong GS. This may result in     a DoS due to a local user changing the frames.

  - CVE-2006-1056     AMD64 machines (and other 7th and 8th generation     AuthenticAMD processors) were found to be vulnerable to     sensitive information leakage, due to how they handle     saving and restoring the FOP, FIP, and FDP x87 registers     in FXSAVE/FXRSTOR when an exception is pending. This     allows a process to determine portions of the state of     floating point instructions of other processes.

  - CVE-2006-1242     Marco Ivaldi discovered that there was an unintended     information disclosure allowing remote attackers to     bypass protections against Idle Scans (nmap -sI) by     abusing the ID field of IP packets and bypassing the     zero IP ID in DF packet countermeasure. This was a     result of the ip_push_pending_frames function improperly     incremented the IP ID field when sending a RST after     receiving unsolicited TCP SYN-ACK packets.

  - CVE-2006-1368     Shaun Tancheff discovered a buffer overflow (boundary     condition error) in the USB Gadget RNDIS implementation     allowing remote attackers to cause a DoS. While creating     a reply message, the driver allocated memory for the     reply data, but not for the reply structure. The kernel     fails to properly bounds-check user-supplied data before     copying it to an insufficiently sized memory buffer.
    Attackers could crash the system, or possibly execute     arbitrary machine code.

  - CVE-2006-1523     Oleg Nesterov reported an unsafe BUG_ON call in signal.c     which was introduced by RCU signal handling. The BUG_ON     code is protected by siglock while the code in     switch_exit_pids() uses tasklist_lock. It may be     possible for local users to exploit this to initiate a     denial of service attack (DoS).

  - CVE-2006-1524     Hugh Dickins discovered an issue in the madvise_remove()     function wherein file and mmap restrictions are not     followed, allowing local users to bypass IPC permissions     and replace portions of readonly tmpfs files with     zeroes.

  - CVE-2006-1525     Alexandra Kossovsky reported a NULL pointer dereference     condition in ip_route_input() that can be triggered by a     local user by requesting a route for a multicast IP     address, resulting in a denial of service (panic).

  - CVE-2006-1857     Vlad Yasevich reported a data validation issue in the     SCTP subsystem that may allow a remote user to overflow     a buffer using a badly formatted HB-ACK chunk, resulting     in a denial of service.

  - CVE-2006-1858     Vlad Yasevich reported a bug in the bounds checking code     in the SCTP subsystem that may allow a remote attacker     to trigger a denial of service attack when rounded     parameter lengths are used to calculate parameter     lengths instead of the actual values.

  - CVE-2006-1863     Mark Mosely discovered that chroots residing on an CIFS     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-1864     Mark Mosely discovered that chroots residing on an SMB     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-2271     The 'Mu security team' discovered that carefully crafted     ECNE chunks can cause a kernel crash by accessing     incorrect state stable entries in the SCTP networking     subsystem, which allows denial of service.

  - CVE-2006-2272     The 'Mu security team' discovered that fragmented SCTP     control chunks can trigger kernel panics, which allows     for denial of service attacks.

  - CVE-2006-2274     It was discovered that SCTP packets with two initial     bundled data packets can lead to infinite recursion,     which allows for denial of service attacks.

Updated kernel packages are now available as part of ongoing support and maintenance of Red Hat Enterprise Linux version 3. This is the eighth regular update.

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

The Linux kernel handles the basic functions of the operating system.

This is the eighth regular kernel update to Red Hat Enterprise Linux 3.

New features introduced by this update include :

  - addition of the adp94xx and dcdbas device drivers -     diskdump support on megaraid_sas, qlogic, and swap     partitions - support for new hardware via driver and     SCSI white-list updates

There were many bug fixes in various parts of the kernel. The ongoing effort to resolve these problems has resulted in a marked improvement in the reliability and scalability of Red Hat Enterprise Linux 3.

There were numerous driver updates and security fixes (elaborated below). Other key areas affected by fixes in this update include the networking subsystem, the NFS and autofs4 file systems, the SCSI and USB subsystems, and architecture-specific handling affecting AMD Opteron and Intel EM64T processors.

The following device drivers have been added or upgraded to new versions :

adp94xx -------- 1.0.8 (new) bnx2 ----------- 1.4.38 cciss ---------- 2.4.60.RH1 dcdbas --------- 5.6.0-1 (new) e1000 ---------- 7.0.33-k2 emulex --------- 7.3.6 forcedeth ------ 0.30 ipmi ----------- 35.13 qlogic --------- 7.07.04b6 tg3 ------------ 3.52RH

The following security bugs were fixed in this update :

  - a flaw in the USB devio handling of device removal that     allowed a local user to cause a denial of service     (crash) (CVE-2005-3055, moderate)

  - a flaw in the exec() handling of multi-threaded tasks     using ptrace() that allowed a local user to cause a     denial of service (hang of a user process)     (CVE-2005-3107, low)

  - a difference in 'sysretq' operation of EM64T (as opposed     to Opteron) processors that allowed a local user to     cause a denial of service (crash) upon return from     certain system calls (CVE-2006-0741 and CVE-2006-0744,     important)

  - a flaw in unaligned accesses handling on Intel Itanium     processors that allowed a local user to cause a denial     of service (crash) (CVE-2006-0742, important)

  - an info leak on AMD-based x86 and x86_64 systems that     allowed a local user to retrieve the floating point     exception state of a process run by a different user     (CVE-2006-1056, important)

  - a flaw in IPv4 packet output handling that allowed a     remote user to bypass the zero IP ID countermeasure on     systems with a disabled firewall (CVE-2006-1242, low)

  - a minor info leak in socket option handling in the     network code (CVE-2006-1343, low)

  - a flaw in IPv4 netfilter handling for the unlikely use     of SNMP NAT processing that allowed a remote user to     cause a denial of service (crash) or potential memory     corruption (CVE-2006-2444, moderate)

Note: The kernel-unsupported package contains various drivers and modules that are unsupported and therefore might contain security problems that have not been addressed.

All Red Hat Enterprise Linux 3 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

Updated kernel packages that fix several security issues in the Red Hat Enterprise Linux 4 kernel are now available.

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

The Linux kernel handles the basic functions of the operating system.

These new kernel packages contain fixes for the security issues described below :

* a flaw in the IPv6 implementation that allowed a local user to cause a denial of service (infinite loop and crash) (CVE-2005-2973, important)

* a flaw in the bridge implementation that allowed a remote user to cause forwarding of spoofed packets via poisoning of the forwarding table with already dropped frames (CVE-2005-3272, moderate)

* a flaw in the atm module that allowed a local user to cause a denial of service (panic) via certain socket calls (CVE-2005-3359, important)

* a flaw in the NFS client implementation that allowed a local user to cause a denial of service (panic) via O_DIRECT writes (CVE-2006-0555, important)

* a difference in 'sysretq' operation of EM64T (as opposed to Opteron) processors that allowed a local user to cause a denial of service (crash) upon return from certain system calls (CVE-2006-0741 and CVE-2006-0744, important)

* a flaw in the keyring implementation that allowed a local user to cause a denial of service (OOPS) (CVE-2006-1522, important)

* a flaw in IP routing implementation that allowed a local user to cause a denial of service (panic) via a request for a route for a multicast IP (CVE-2006-1525, important)

* a flaw in the SCTP-netfilter implementation that allowed a remote user to cause a denial of service (infinite loop) (CVE-2006-1527, important)

* a flaw in the sg driver that allowed a local user to cause a denial of service (crash) via a dio transfer to memory mapped (mmap) IO space (CVE-2006-1528, important)

* a flaw in the threading implementation that allowed a local user to cause a denial of service (panic) (CVE-2006-1855, important)

* two missing LSM hooks that allowed a local user to bypass the LSM by using readv() or writev() (CVE-2006-1856, moderate)

* a flaw in the virtual memory implementation that allowed local user to cause a denial of service (panic) by using the lsof command (CVE-2006-1862, important)

* a directory traversal vulnerability in smbfs that allowed a local user to escape chroot restrictions for an SMB-mounted filesystem via '..\\' sequences (CVE-2006-1864, moderate)

* a flaw in the ECNE chunk handling of SCTP that allowed a remote user to cause a denial of service (panic) (CVE-2006-2271, moderate)

* a flaw in the handling of COOKIE_ECHO and HEARTBEAT control chunks of SCTP that allowed a remote user to cause a denial of service (panic) (CVE-2006-2272, moderate)

* a flaw in the handling of DATA fragments of SCTP that allowed a remote user to cause a denial of service (infinite recursion and crash) (CVE-2006-2274, moderate)

All Red Hat Enterprise Linux 4 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

A number of vulnerabilities were discovered and corrected in the Linux 2.6 kernel :

Prior to Linux kernel 2.6.16.5, the kernel does not properly handle uncanonical return addresses on Intel EM64T CPUs which causes the kernel exception handler to run on the user stack with the wrong GS (CVE-2006-0744).

The selinux_ptrace logic hooks in SELinux for 2.6.6 allow local users with ptrace permissions to change the tracer SID to an SID of another process (CVE-2006-1052).

Prior to 2.6.16, the ip_push_pending_frames function increments the IP ID field when sending a RST after receiving unsolicited TCP SYN-ACK packets, which allows a remote attacker to conduct an idle scan attack, bypassing any intended protection against such an attack (CVE-2006-1242).

In kernel 2.6.16.1 and some earlier versions, the sys_add_key function in the keyring code allows local users to cause a DoS (OOPS) via keyctl requests that add a key to a user key instead of a keyring key, causing an invalid dereference (CVE-2006-1522).

Prior to 2.6.16.8, the ip_route_input function allows local users to cause a DoS (panic) via a request for a route for a multicast IP address, which triggers a null dereference (CVE-2006-1525).

Prior to 2.6.16.13, the SCTP-netfilter code allows remote attackers to cause a DoS (infinite loop) via unknown vectors that cause an invalid SCTP chunk size to be processed (CVE-2006-1527).

Prior to 2.6.16, local users can bypass IPC permissions and modify a read-only attachment of shared memory by using mprotect to give write permission to the attachment (CVE-2006-2071).

Prior to 2.6.17, the ECNE chunk handling in SCTP (lksctp) allows remote attackers to cause a DoS (kernel panic) via an unexpected chucnk when the session is in CLOSED state (CVE-2006-2271).

Prior to 2.6.17, SCTP (lksctp) allows remote attacker to cause a DoS (kernel panic) via incoming IP fragmented COOKIE_ECHO and HEARTBEAT SCTP control chunks (CVE-2006-2272).

In addition to these security fixes, other fixes have been included such as :

  - fix a scheduler deadlock

    - Yenta oops fix

    - ftdi_sio: adds support for iPlus devices

    - enable kprobes on i386 and x86_64

    - avoid a panic on bind mount of autofs owned directory

    - fix a kernel OOPs when booting with 'console=ttyUSB0'       but without a USB-serial dongle plugged in

  - make dm-mirror not issue invalid resync requests

    - fix media change detection on scsi removable devices

    - add support for the realtek 8168 chipset

    - update hfsplus driver to 2.6.16 state

    - backport 'Gilgal' support from e1000 7.0.33

    - selected ACPI video fixes

    - update 3w-9xxx to 2.26.02.005 (9550SX support)

    - fix a deadlock in the ext2 filesystem

    - fix usbserial use-after-free bug

    - add i945GM DRI support

    - S3 resume fixes

    - add ECS PF22 hda model support

    - SMP suspend

    - CPU hotplug

    - miscellaneous AGP fixes

    - added sata-suspend patch for 2.6.12 for Napa platform

The provided packages are patched to fix these vulnerabilities. All users are encouraged to upgrade to these updated kernels.

As well, updated mkinitrd and bootsplash packages are provided to fix minor issues; users should upgrade both packages prior to installing a new kernel.

To update your kernel, please follow the directions located at :

http://www.mandriva.com/en/security/kernelupdate

This update includes a number of security issues that have been fixed upstream over the last week or so.

i386/x86-64: Fix x87 information leak between processes (CVE-2006-1056) ip_route_input panic fix (CVE-2006-1525) fix MADV_REMOVE vulnerability (CVE-2006-1524) shmat: stop mprotect from giving write permission to a readonly attachment (CVE-2006-1524) Fix MPBL0010 driver insecure sysfs permissions x86_64: When user could have changed RIP always force IRET (CVE-2006-0744) Fix RCU signal handling Keys: Fix oops when adding key to non-keyring (CVE-2006-1522) sysfs: zero terminate sysfs write buffers (CVE-2006-1055)

It also includes various other fixes from the -stable tree. Full changelogs are available from :

http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.9 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.8 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.7 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.6 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.5 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.4 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.3 http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.2

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

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2006-0493.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2006-0437.

ID	Name	Product	Family	Severity
79477	OracleVM 3.1 : xen (OVMSA-2012-0021)	Nessus	OracleVM Local Security Checks	high
79476	OracleVM 3.0 : xen (OVMSA-2012-0020)	Nessus	OracleVM Local Security Checks	high
27877	Ubuntu 5.04 / 5.10 / 6.06 LTS : linux-source-2.6.10/2.6.12/2.6.15 vulnerabilities (USN-302-1)	Nessus	Ubuntu Local Security Checks	high
22645	Debian DSA-1103-1 : kernel-source-2.6.8 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
22135	CentOS 3 : kernel (CESA-2006:0437)	Nessus	CentOS Local Security Checks	high
22086	RHEL 3 : kernel (RHSA-2006:0437)	Nessus	Red Hat Local Security Checks	high
21997	CentOS 4 : kernel (CESA-2006:0493)	Nessus	CentOS Local Security Checks	high
21592	RHEL 4 : kernel (RHSA-2006:0493)	Nessus	Red Hat Local Security Checks	high
21575	Mandrake Linux Security Advisory : kernel (MDKSA-2006:086)	Nessus	Mandriva Local Security Checks	high
21253	Fedora Core 4 : kernel-2.6.16-1.2096_FC4 (2006-423)	Nessus	Fedora Local Security Checks	medium
801418	CentOS RHSA-2006-0493 Security Check	Log Correlation Engine	Generic	high
801417	CentOS RHSA-2006-0437 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2006-0744

critical

Tenable Plugins

high

high

high

critical

high

high

high

high

high

medium

high

high