A number of vulnerabilities have been discovered in the Linux kernel.

  - CAN-2003-0461: /proc/tty/driver/serial in Linux 2.4.x     reveals the exact number of characters used in serial     links, which could allow local users to obtain     potentially sensitive information such as the length of     passwords. This bug has been fixed by restricting access     to /proc/tty/driver/serial.
  - CAN-2003-0462: A race condition in the way env_start and     env_end pointers are initialized in the execve system     call and used in fs/proc/base.c on Linux 2.4 allows     local users to cause a denial of service (crash).

  - CAN-2003-0476: The execve system call in Linux 2.4.x     records the file descriptor of the executable process in     the file table of the calling process, which allows     local users to gain read access to restricted file     descriptors.

  - CAN-2003-0501: The /proc filesystem in Linux allows     local users to obtain sensitive information by opening     various entries in /proc/self before executing a setuid     program, which causes the program to fail to change the     ownership and permissions of those entries.

  - CAN-2003-0550: The STP protocol, as enabled in Linux     2.4.x, does not provide sufficient security by design,     which allows attackers to modify the bridge topology.
    This bug has been fixed by disabling STP by default.

  - CAN-2003-0551: The STP protocol, as enabled in Linux     2.4.x, does not provide sufficient security by design,     which allows attackers to modify the bridge topology.

  - CAN-2003-0552: Linux 2.4.x allows remote attackers to     spoof the bridge forwarding table via forged packets     whose source addresses are the same as the target.

  - CAN-2003-0018: Linux kernel 2.4.10 through 2.4.21-pre4     does not properly handle the O_DIRECT feature, which     allows local attackers with write privileges to read     portions of previously deleted files, or cause file     system corruption. This bug has been fixed by disabling     O_DIRECT.

  - CAN-2003-0619: Integer signedness error in the decode_fh     function of nfs3xdr.c in Linux kernel before 2.4.21     allows remote attackers to cause a denial of service     (kernel panic) via a negative size value within XDR data     of an NFSv3 procedure call.

This advisory covers only the i386 and alpha architectures. Other architectures will be covered by separate advisories.

The IA-64 maintainers fixed several security related bugs in the Linux kernel 2.4.17 used for the IA-64 architecture, mostly by backporting fixes from 2.4.18. The corrections are listed below with the identification from the Common Vulnerabilities and Exposures (CVE) project :

  - CAN-2003-0001 :
    Multiple ethernet network interface card (NIC) device     drivers do not pad frames with null bytes, which allows     remote attackers to obtain information from previous     packets or kernel memory by using malformed packets, as     demonstrated by Etherleak.

  - CAN-2003-0018 :

    Linux kernel 2.4.10 through 2.4.21-pre4 does not     properly handle the O_DIRECT feature, which allows local     attackers with write privileges to read portions of     previously deleted files, or cause file system     corruption.

  - CAN-2003-0127 :

    The kernel module loader in Linux kernel 2.2.x before     2.2.25, and 2.4.x before 2.4.21, allows local users to     gain root privileges by using ptrace to attach to a     child process which is spawned by the kernel.

  - CAN-2003-0461 :

    The virtual file /proc/tty/driver/serial in Linux 2.4.x     reveals the exact number of characters used in serial     links, which could allow local users to obtain     potentially sensitive information such as the length of     passwords.

  - CAN-2003-0462 :

    A race condition in the way env_start and env_end     pointers are initialized in the execve system call and     used in fs/proc/base.c on Linux 2.4 allows local users     to cause a denial of service (crash).

  - CAN-2003-0476 :

    The execve system call in Linux 2.4.x records the file     descriptor of the executable process in the file table     of the calling process, which allows local users to gain     read access to restricted file descriptors.

  - CAN-2003-0501 :

    The /proc filesystem in Linux allows local users to     obtain sensitive information by opening various entries     in /proc/self before executing a setuid program, which     causes the program to fail to change the ownership and     permissions of those entries.

  - CAN-2003-0550 :

    The STP protocol, as enabled in Linux 2.4.x, does not     provide sufficient security by design, which allows     attackers to modify the bridge topology.

  - CAN-2003-0551 :

    The STP protocol implementation in Linux 2.4.x does not     properly verify certain lengths, which could allow     attackers to cause a denial of service.

  - CAN-2003-0552 :

    Linux 2.4.x allows remote attackers to spoof the bridge     Forwarding table via forged packets whose source     addresses are the same as the target.

  - CAN-2003-0961 :

    An integer overflow in brk system call (do_brk function)     for Linux kernel 2.4.22 and earlier allows local users     to gain root privileges.

  - CAN-2003-0985 :

    The mremap system call (do_mremap) in Linux kernel 2.4     and 2.6 does not properly perform boundary checks, which     allows local users to cause a denial of service and     possibly gain privileges by causing a remapping of a     virtual memory area (VMA) to create a zero length VMA.

The kernel in Red Hat Linux Advanced Server 2.1 is vulnerable to a local denial of service attack. Updated packages are available which address this vulnerability.

[Updated 28 August 2003] Added CVE-2003-0461 to the list of security issues that were fixed by this advisory (there are no changes to the packages themselves).

The Linux kernel handles the basic functions of the operating system.
A vulnerability in the Linux kernel has been discovered in which a non-root user can cause the machine to freeze. This kernel addresses the vulnerability.

Note: This bug is specific to the x86 architecture kernels only, and does not affect ia64 or other architectures.

In addition, /proc/tty/driver/serial reveals the exact number of characters used in serial links, which could allow local users to obtain potentially sensitive information such as password lengths.

All users should upgrade to these errata packages, which are not vulnerable to these issues.

Thanks go to Christopher Devine for reporting the vulnerability on Bugtraq, and Petr Vandrovec for being the first to supply a fix to the community.

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

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

This is the second regular kernel update to Red Hat Enterprise Linux version 3. It contains several minor security fixes, many bug fixes, device driver updates, new hardware support, and the introduction of Linux Syscall Auditing support.

There were bug fixes in many different parts of the kernel, the bulk of which addressed unusual situations such as error handling, race conditions, and resource starvation. The combined effect of the approximately 140 fixes is a strong improvement in the reliability and durability of Red Hat Enterprise Linux. Some of the key areas affected are disk drivers, network drivers, USB support, x86_64 and ppc64 platform support, ia64 32-bit emulation layer enablers, and the VM, NFS, IPv6, and SCSI subsystems.

A significant change in the SCSI subsystem (the disabling of the scsi-affine-queue patch) should significantly improve SCSI disk driver performance in many scenarios. There were 10 Bugzillas against SCSI performance problems addressed by this change.

The following drivers have been upgraded to new versions :

bonding ---- 2.4.1 cciss ------ 2.4.50.RH1 e1000 ------ 5.2.30.1-k1 fusion ----- 2.05.11.03 ipr -------- 1.0.3 ips -------- 6.11.07 megaraid2 -- 2.10.1.1 qla2x00 ---- 6.07.02-RH1 tg3 -------- 3.1 z90crypt --- 1.1.4

This update introduces support for the new Intel EM64T processor. A new 'ia32e' architecture has been created to support booting on platforms based on either the original AMD Opteron CPU or the new Intel EM64T CPU. The existing 'x86_64' architecture has remained optimized for Opteron systems. Kernels for both types of systems are built from the same x86_64-architecture sources and share a common kernel source RPM (kernel-source-2.4.21-15.EL.x86_64.rpm).

Other highlights in this update include a major upgrade to the SATA infrastructure, addition of IBM JS20 Power Blade support, and creation of an optional IBM eServer zSeries On-Demand Timer facility for reducing idle CPU overhead.

The following security issues were addressed in this update :

A minor flaw was found where /proc/tty/driver/serial reveals the exact character counts for serial links. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0461 to this issue.

The kernel strncpy() function in Linux 2.4 and 2.5 does not pad the target buffer with null bytes on architectures other than x86, as opposed to the expected libc behavior, which could lead to information leaks. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0465 to this issue.

A minor data leak was found in two real time clock drivers (for /dev/rtc). The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2003-0984 to this issue.

A flaw in the R128 Direct Render Infrastructure (dri) driver could allow local privilege escalation. This driver is part of the kernel-unsupported package. The Common Vulnera- bilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0003 to this issue.

A flaw in ncp_lookup() in ncpfs could allow local privilege escalation. The ncpfs module allows a system to mount volumes of NetWare servers or print to NetWare printers and is in the kernel-unsupported package. The Common Vulnera- bilities and Exposures project (cve.mitre.org) has assigned the name CVE-2004-0010 to this issue.

(Note that the kernel-unsupported package contains drivers and other 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 are now available as part of ongoing support
and maintenance of Red Hat Enterprise Linux version 3. This is the
second regular update.

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

This is the second regular kernel update to Red Hat Enterprise Linux
version 3. It contains several minor security fixes, many bug fixes,
device driver updates, new hardware support, and the introduction of
Linux Syscall Auditing support.

There were bug fixes in many different parts of the kernel, the bulk
of which addressed unusual situations such as error handling, race
conditions, and resource starvation. The combined effect of the
approximately 140 fixes is a strong improvement in the reliability and
durability of Red Hat Enterprise Linux. Some of the key areas affected
are disk drivers, network drivers, USB support, x86_64 and ppc64
platform support, ia64 32-bit emulation layer enablers, and the VM,
NFS, IPv6, and SCSI subsystems.

A significant change in the SCSI subsystem (the disabling of the
scsi-affine-queue patch) should significantly improve SCSI disk driver
performance in many scenarios. There were 10 Bugzillas against SCSI
performance problems addressed by this change.

The following drivers have been upgraded to new versions :

bonding ---- 2.4.1 cciss ------ 2.4.50.RH1 e1000 ------ 5.2.30.1-k1
fusion ----- 2.05.11.03 ipr -------- 1.0.3 ips -------- 6.11.07
megaraid2 -- 2.10.1.1 qla2x00 ---- 6.07.02-RH1 tg3 -------- 3.1
z90crypt --- 1.1.4

This update introduces support for the new Intel EM64T processor. A
new 'ia32e' architecture has been created to support booting on
platforms based on either the original AMD Opteron CPU or the new
Intel EM64T CPU. The existing 'x86_64' architecture has remained
optimized for Opteron systems. Kernels for both types of systems are
built from the same x86_64-architecture sources and share a common
kernel source RPM (kernel-source-2.4.21-15.EL.x86_64.rpm).

Other highlights in this update include a major upgrade to the SATA
infrastructure, addition of IBM JS20 Power Blade support, and creation
of an optional IBM eServer zSeries On-Demand Timer facility for
reducing idle CPU overhead.

The following security issues were addressed in this update :

A minor flaw was found where /proc/tty/driver/serial reveals the exact
character counts for serial links. The Common Vulnerabilities and
Exposures project (cve.mitre.org) has assigned the name CVE-2003-0461
to this issue.

The kernel strncpy() function in Linux 2.4 and 2.5 does not pad the
target buffer with null bytes on architectures other than x86, as
opposed to the expected libc behavior, which could lead to information
leaks. The Common Vulnerabilities and Exposures project
(cve.mitre.org) has assigned the name CVE-2003-0465 to this issue.

A minor data leak was found in two real time clock drivers (for
/dev/rtc). The Common Vulnerabilities and Exposures project
(cve.mitre.org) has assigned the name CVE-2003-0984 to this issue.

A flaw in the R128 Direct Render Infrastructure (dri) driver could
allow local privilege escalation. This driver is part of the
kernel-unsupported package. The Common Vulnera- bilities and Exposures
project (cve.mitre.org) has assigned the name CVE-2004-0003 to this
issue.

A flaw in ncp_lookup() in ncpfs could allow local privilege
escalation. The ncpfs module allows a system to mount volumes of
NetWare servers or print to NetWare printers and is in the
kernel-unsupported package. The Common Vulnera- bilities and Exposures
project (cve.mitre.org) has assigned the name CVE-2004-0010 to this
issue.

(Note that the kernel-unsupported package contains drivers and other
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.

The kernel in Red Hat Linux Advanced Server 2.1 is vulnerable to a
local denial of service attack. Updated packages are available which
address this vulnerability.

[Updated 28 August 2003] Added CVE-2003-0461 to the list of security
issues that were fixed by this advisory (there are no changes to the
packages themselves).

The Linux kernel handles the basic functions of the operating system.
A vulnerability in the Linux kernel has been discovered in which a
non-root user can cause the machine to freeze. This kernel addresses
the vulnerability.

Note: This bug is specific to the x86 architecture kernels only, and
does not affect ia64 or other architectures.

In addition, /proc/tty/driver/serial reveals the exact number of
characters used in serial links, which could allow local users to
obtain potentially sensitive information such as password lengths.

All users should upgrade to these errata packages, which are not
vulnerable to these issues.

Thanks go to Christopher Devine for reporting the vulnerability on
Bugtraq, and Petr Vandrovec for being the first to supply a fix to the
community.

ID	Name	Product	Family	Published	Updated	Severity
15195	Debian DSA-358-4 : linux-kernel-2.4.18 - several vulnerabilities	Nessus	Debian Local Security Checks	9/29/2004	1/4/2021	medium
15260	Debian DSA-423-1 : linux-kernel-2.4.17-ia64 - several vulnerabilities	Nessus	Debian Local Security Checks	9/29/2004	1/4/2021	high
12337	RHEL 2.1 : kernel (RHSA-2002:263)	Nessus	Red Hat Local Security Checks	7/6/2004	1/14/2021	low
12494	RHEL 3 : kernel (RHSA-2004:188)	Nessus	Red Hat Local Security Checks	7/6/2004	1/14/2021	high
801593	Red Hat 2004-188 Security Check	Log Correlation Engine	Generic			high
801576	Red Hat 2002-263 Security Check	Log Correlation Engine	Generic			high

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