Some futex functions in futex.c for Linux kernel 2.6.x perform get_user calls while holding the mmap_sem semaphore, which could allow local users to cause a deadlock condition in do_page_fault by triggering get_user faults while another thread is executing mmap or other functions.

Updated kernel packages are now available as part of ongoing support and maintenance of Red Hat Enterprise Linux version 4. This is the first regular update.

[Updated 9 August 2005] The advisory text has been updated to show that this update also contained fixes for the security issues named CVE-2005-0209 and CVE-2005-0937. No changes have been made to the packages associated with this advisory.

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

This is the first regular kernel update to Red Hat Enterprise Linux 4.

A flaw affecting the auditing code was discovered. On Itanium architectures a local user could use this flaw to cause a denial of service (crash). This issue is rated as having important security impact (CVE-2005-0136).

A flaw was discovered in the servicing of a raw device ioctl. A local user who has access to raw devices could use this flaw to write to kernel memory and cause a denial of service or potentially gain privileges. This issue is rated as having moderate security impact (CVE-2005-1264).

A flaw in fragment forwarding was discovered that affected the netfilter subsystem for certain network interface cards. A remote attacker could send a set of bad fragments and cause a denial of service (system crash). Acenic and SunGEM network interfaces were the only adapters affected, which are in widespread use. (CVE-2005-0209)

A flaw in the futex functions was discovered affecting the Linux 2.6 kernel. A local user could use this flaw to cause a denial of service (system crash). (CVE-2005-0937)

New features introduced by this update include: - Fixed TCP BIC congestion handling. - Diskdump support for more controllers (megaraid, SATA) - Device mapper multipath support - AMD64 dual core support. - Intel ICH7 hardware support.

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 4.

The following device drivers have been upgraded to new versions:
ata_piix -------- 1.03 bonding --------- 2.6.1 e1000 ----------- 5.6.10.1-k2-NAPI e100 ------------ 3.3.6-k2-NAPI ibmveth --------- 1.03 libata ---------- 1.02 to 1.10 lpfc ------------ 0:8.0.16 to 0:8.0.16.6_x2 megaraid_mbox --- 2.20.4.0 to 2.20.4.5 megaraid_mm ----- 2.20.2.0-rh1 to 2.20.2.5 sata_nv --------- 0.03 to 0.6 sata_promise
---- 1.00 to 1.01 sata_sil -------- 0.8 sata_sis -------- 0.5 sata_svw
-------- 1.05 sata_sx4 -------- 0.7 sata_via -------- 1.0 sata_vsc
-------- 1.0 tg3 ------------- 3.22-rh ipw2100 --------- 1.0.3 ipw2200
--------- 1.0.0

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.

Alexander Nyberg discovered an integer overflow in the sysfs_write_file() function. A local attacker could exploit this to crash the kernel or possibly even execute arbitrary code with root privileges by writing to an user-writable file in /sys under certain low-memory conditions. However, there are very few cases where a user-writeable sysfs file actually exists. (CAN-2005-0867)

Olof Johansson discovered a Denial of Service vulnerability in the futex functions, which provide semaphores for exclusive locking of resources. A local attacker could possibly exploit this to cause a kernel deadlock. (CAN-2005-0937)

In addition this update fixes two race conditions in the ext3 and jfs file system drivers, which could lead to a kernel crash under certain (unusual) conditions. However, these cannot easily be triggered by users, thus they are not security sensitive.
(http://linux.bkbits.net:8080/linux-2.5/gnupatch@4248d87aETPJX79hVXl4o wAUwu2SmQ, http://linux.bkbits.net:8080/linux-2.6/cset@1.2181.46.242)

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.

Multiple vulnerabilities in the Linux kernel have been discovered and fixed in this update. The following CVE names have been fixed in the LE2005 kernel :

Colin Percival discovered a vulnerability in Intel's Hyper-Threading technology could allow a local user to use a malicious thread to create covert channels, monitor the execution of other threads, and obtain sensitive information such as cryptographic keys via a timing attack on memory cache misses. This has been corrected by disabling HT support in all kernels (CVE-2005-0109).

An information leak in the ext2 filesystem code in kernels prior to 2.6.11.6 was found where when a new directory is created, the ext2 block written to disk is not initialized (CVE-2005-0400).

A flaw when freeing a pointer in load_elf_library was found in kernels prior to 2.6.11.6 that could be abused by a local user to potentially crash the machine causing a Denial of Service (CVE-2005-0749).

A problem with the Bluetooth kernel stack in kernels 2.4.6 through 2.4.30-rc1 and 2.6 through 2.6.11.5 could be used by a local attacker to gain root access or crash the machine (CVE-2005-0750).

Paul Starzetz found an integer overflow in the ELF binary format loader's code dump function in kernels prior to and including 2.4.31-pre1 and 2.6.12-rc4. By creating and executing a specially crafted ELF executable, a local attacker could exploit this to execute arbitrary code with root and kernel privileges (CVE-2005-1263).

The drivers for raw devices used the wrong function to pass arguments to the underlying block device in 2.6.x kernels. This made the kernel address space accessible to user-space applications allowing any local user with at least read access to a device in /dev/raw/* (usually only root) to execute arbitrary code with kernel privileges (CVE-2005-1264).

The it87 and via686a hardware monitor drivers in kernels prior to 2.6.11.8 and 2.6.12 prior to 2.6.12-rc2 created a sysfs file named 'alarms' with write permissions although they are not designed to be writable. This allowed a local user to crash the kernel by attempting to write to these files (CVE-2005-1369).

In addition to the above-noted CVE-2005-0109, CVE-2005-0400, CVE-2005-0749, CVE-2005-0750, and CVE-2005-1369 fixes, the following CVE names have been fixed in the 10.1 kernel :

The POSIX Capability Linux Security Module (LSM) for 2.6 kernels up to and including 2.6.8.1 did not properly handle the credentials of a process that is launched before the module is loaded, which could be used by local attackers to gain elevated privileges (CVE-2004-1337).

A flaw in the Linux PPP driver in kernel 2.6.8.1 was found where on systems allowing remote users to connect to a server via PPP, a remote client could cause a crash, resulting in a Denial of Service (CVE-2005-0384).

George Guninski discovered a buffer overflow in the ATM driver in kernels 2.6.10 and 2.6.11 before 2.6.11-rc4 where the atm_get_addr() function does not validate its arguments sufficiently which could allow a local attacker to overwrite large portions of kernel memory by supplying a negative length argument. This could potentially lead to the execution of arbitrary code (CVE-2005-0531).

The reiserfs_copy_from_user_to_file_region function in reiserfs/file.c before kernel 2.6.11, when running on 64-bit architectures, could allow local users to trigger a buffer overflow as a result of casting discrepancies between size_t and int data types. This could allow an attacker to overwrite kernel memory, crash the machine, or potentially obtain root access (CVE-2005-0532).

A race condition in the Radeon DRI driver in kernel 2.6.8.1 allows a local user with DRI privileges to execute arbitrary code as root (CVE-2005-0767).

Access was not restricted to the N_MOUSE discipline for a TTY in kernels prior to 2.6.11. This could allow local attackers to obtain elevated privileges by injecting mouse or keyboard events into other user's sessions (CVE-2005-0839).

Some futex functions in futex.c in 2.6 kernels performed get_user calls while holding the mmap_sem semaphore, which could allow a local attacker to cause a deadlock condition in do_page_fault by triggering get_user faults while another thread is executing mmap or other functions (CVE-2005-0937).

In addition to the above-noted CVE-2004-1337, CVE-2005-0109, CVE-2005-0384, CVE-2005-0400, CVE-2005-0531, CVE-2005-0532, CVE-2005-0749, CVE-2005-0750, CVE-2005-0767, CVE-2005-0839, CVE-2005-0937, CVE-2005-1263, CVE-2005-1264, and CVE-2005-1369 fixes, the following CVE names have been fixed in the 10.0/ Corporate 3.0 kernels :

A race condition in the setsid function in kernels before 2.6.8.1 could allow a local attacker to cause a Denial of Service and possibly access portions of kernel memory related to TTY changes, locking, and semaphores (CVE-2005-0178).

When forwarding fragmented packets in kernel 2.6.8.1, a hardware assisted checksum could only be used once which could lead to a Denial of Service attack or crash by remote users (CVE-2005-0209).

A signedness error in the copy_from_read_buf function in n_tty.c before kernel 2.6.11 allows local users to read kernel memory via a negative argument (CVE-2005-0530).

A vulnerability in the fib_seq_start() function allowed a local user to crash the system by readiung /proc/net/route in a certain way, causing a Denial of Service (CVE-2005-1041).

A vulnerability in the Direct Rendering Manager (DRM) driver in the 2.6 kernel does not properly check the DMA lock, which could allow remote attackers or local users to cause a Denial of Service (X Server crash) and possibly modify the video output (CVE-2004-1056).

The remote Redhat Enterprise Linux 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2005:420 advisory.

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

    This is the first regular kernel update to Red Hat Enterprise Linux 4.

    A flaw affecting the auditing code was discovered.  On Itanium     architectures a local user could use this flaw to cause a denial of service     (crash).  This issue is rated as having important security impact     (CAN-2005-0136).

    A flaw was discovered in the servicing of a raw device ioctl.  A local user     who has access to raw devices could use this flaw to write to kernel memory     and cause a denial of service or potentially gain privileges.  This issue     is rated as having moderate security impact (CAN-2005-1264).

    A flaw in fragment forwarding was discovered that affected the netfilter     subsystem for certain network interface cards. A remote attacker could send     a set of bad fragments and cause a denial of service (system crash). Acenic     and SunGEM network interfaces were the only adapters affected, which are in     widespread use. (CAN-2005-0209)

    A flaw in the futex functions was discovered affecting the Linux 2.6     kernel.  A local user could use this flaw to cause a denial of service     (system crash). (CAN-2005-0937)

    New features introduced by this update include:
    - Fixed TCP BIC congestion handling.
    - Diskdump support for more controllers (megaraid, SATA)
    - Device mapper multipath support
    - AMD64 dual core support.
    - Intel ICH7 hardware support.

    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 4.

    The following device drivers have been upgraded to new versions:
     ata_piix -------- 1.03      bonding --------- 2.6.1      e1000 ----------- 5.6.10.1-k2-NAPI      e100 ------------ 3.3.6-k2-NAPI      ibmveth --------- 1.03      libata ---------- 1.02 to 1.10      lpfc ------------ 0:8.0.16 to 0:8.0.16.6_x2      megaraid_mbox --- 2.20.4.0 to 2.20.4.5      megaraid_mm ----- 2.20.2.0-rh1 to 2.20.2.5      sata_nv --------- 0.03 to 0.6      sata_promise ---- 1.00 to 1.01      sata_sil -------- 0.8      sata_sis -------- 0.5      sata_svw -------- 1.05      sata_sx4 -------- 0.7      sata_via -------- 1.0      sata_vsc -------- 1.0      tg3 ------------- 3.22-rh      ipw2100 --------- 1.0.3      ipw2200 --------- 1.0.0

    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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2005-420.

ID	Name	Product	Family	Severity
21937	CentOS 4 : kernel (CESA-2005:420)	Nessus	CentOS Local Security Checks	high
20497	Ubuntu 4.10 : linux-source-2.6.8.1 vulnerabilities (USN-110-1)	Nessus	Ubuntu Local Security Checks	high
18598	Mandrake Linux Security Advisory : kernel (MDKSA-2005:110)	Nessus	Mandriva Local Security Checks	high
18444	RHEL 4 : Updated kernel packages available for Red Hat Enterprise Linux 4 Update 1 (Important) (RHSA-2005:420)	Nessus	Red Hat Local Security Checks	medium
801407	CentOS RHSA-2005-420 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2005-0937

critical

Tenable Plugins

high

high

high

medium

high