The mm_for_maps function in fs/proc/base.c in the Linux kernel 2.6.30.4 and earlier allows local users to read (1) maps and (2) smaps files under proc/ via vectors related to ELF loading, a setuid process, and a race condition.

From Red Hat Security Advisory 2009:1550 :

Updated kernel packages that fix several security issues and multiple bugs are now available for Red Hat Enterprise Linux 3.

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.

Security fixes :

* when fput() was called to close a socket, the __scm_destroy() function in the Linux kernel could make indirect recursive calls to itself. This could, potentially, lead to a denial of service issue.
(CVE-2008-5029, Important)

* the sendmsg() function in the Linux kernel did not block during UNIX socket garbage collection. This could, potentially, lead to a local denial of service. (CVE-2008-5300, Important)

* the exit_notify() function in the Linux kernel did not properly reset the exit signal if a process executed a set user ID (setuid) application before exiting. This could allow a local, unprivileged user to elevate their privileges. (CVE-2009-1337, Important)

* a flaw was found in the Intel PRO/1000 network driver in the Linux kernel. Frames with sizes near the MTU of an interface may be split across multiple hardware receive descriptors. Receipt of such a frame could leak through a validation check, leading to a corruption of the length check. A remote attacker could use this flaw to send a specially crafted packet that would cause a denial of service or code execution. (CVE-2009-1385, Important)

* the ADDR_COMPAT_LAYOUT and MMAP_PAGE_ZERO flags were not cleared when a setuid or setgid program was executed. A local, unprivileged user could use this flaw to bypass the mmap_min_addr protection mechanism and perform a NULL pointer dereference attack, or bypass the Address Space Layout Randomization (ASLR) security feature.
(CVE-2009-1895, Important)

* it was discovered that, when executing a new process, the clear_child_tid pointer in the Linux kernel is not cleared. If this pointer points to a writable portion of the memory of the new program, the kernel could corrupt four bytes of memory, possibly leading to a local denial of service or privilege escalation. (CVE-2009-2848, Important)

* missing initialization flaws were found in getname() implementations in the IrDA sockets, AppleTalk DDP protocol, NET/ROM protocol, and ROSE protocol implementations in the Linux kernel. Certain data structures in these getname() implementations were not initialized properly before being copied to user-space. These flaws could lead to an information leak. (CVE-2009-3002, Important)

* a NULL pointer dereference flaw was found in each of the following functions in the Linux kernel: pipe_read_open(), pipe_write_open(), and pipe_rdwr_open(). When the mutex lock is not held, the i_pipe pointer could be released by other processes before it is used to update the pipe's reader and writer counters. This could lead to a local denial of service or privilege escalation. (CVE-2009-3547, Important)

Bug fixes :

* this update adds the mmap_min_addr tunable and restriction checks to help prevent unprivileged users from creating new memory mappings below the minimum address. This can help prevent the exploitation of NULL pointer dereference bugs. Note that mmap_min_addr is set to zero (disabled) by default for backwards compatibility. (BZ#512642)

* a bridge reference count problem in IPv6 has been fixed. (BZ#457010)

* enforce null-termination of user-supplied arguments to setsockopt().
(BZ#505514)

* the gcc flag '-fno-delete-null-pointer-checks' was added to the kernel build options. This prevents gcc from optimizing out NULL pointer checks after the first use of a pointer. NULL pointer bugs are often exploited by attackers. Keeping these checks is a safety measure. (BZ#511185)

* a check has been added to the IPv4 code to make sure that rt is not NULL, to help prevent future bugs in functions that call ip_append_data() from being exploitable. (BZ#520300)

Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

From Red Hat Security Advisory 2009:1541 :

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

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.

This update fixes the following security issues :

* a NULL pointer dereference flaw was found in each of the following functions in the Linux kernel: pipe_read_open(), pipe_write_open(), and pipe_rdwr_open(). When the mutex lock is not held, the i_pipe pointer could be released by other processes before it is used to update the pipe's reader and writer counters. This could lead to a local denial of service or privilege escalation. (CVE-2009-3547, Important)

Users should upgrade to these updated packages, which contain a backported patch to correct these issues. The system must be rebooted for this update to take effect.

Updated kernel packages that fix several security issues and multiple bugs are now available for Red Hat Enterprise Linux 3.

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.

Security fixes :

* when fput() was called to close a socket, the __scm_destroy() function in the Linux kernel could make indirect recursive calls to itself. This could, potentially, lead to a denial of service issue.
(CVE-2008-5029, Important)

* the sendmsg() function in the Linux kernel did not block during UNIX socket garbage collection. This could, potentially, lead to a local denial of service. (CVE-2008-5300, Important)

* the exit_notify() function in the Linux kernel did not properly reset the exit signal if a process executed a set user ID (setuid) application before exiting. This could allow a local, unprivileged user to elevate their privileges. (CVE-2009-1337, Important)

* a flaw was found in the Intel PRO/1000 network driver in the Linux kernel. Frames with sizes near the MTU of an interface may be split across multiple hardware receive descriptors. Receipt of such a frame could leak through a validation check, leading to a corruption of the length check. A remote attacker could use this flaw to send a specially crafted packet that would cause a denial of service or code execution. (CVE-2009-1385, Important)

* the ADDR_COMPAT_LAYOUT and MMAP_PAGE_ZERO flags were not cleared when a setuid or setgid program was executed. A local, unprivileged user could use this flaw to bypass the mmap_min_addr protection mechanism and perform a NULL pointer dereference attack, or bypass the Address Space Layout Randomization (ASLR) security feature.
(CVE-2009-1895, Important)

* it was discovered that, when executing a new process, the clear_child_tid pointer in the Linux kernel is not cleared. If this pointer points to a writable portion of the memory of the new program, the kernel could corrupt four bytes of memory, possibly leading to a local denial of service or privilege escalation. (CVE-2009-2848, Important)

* missing initialization flaws were found in getname() implementations in the IrDA sockets, AppleTalk DDP protocol, NET/ROM protocol, and ROSE protocol implementations in the Linux kernel. Certain data structures in these getname() implementations were not initialized properly before being copied to user-space. These flaws could lead to an information leak. (CVE-2009-3002, Important)

* a NULL pointer dereference flaw was found in each of the following functions in the Linux kernel: pipe_read_open(), pipe_write_open(), and pipe_rdwr_open(). When the mutex lock is not held, the i_pipe pointer could be released by other processes before it is used to update the pipe's reader and writer counters. This could lead to a local denial of service or privilege escalation. (CVE-2009-3547, Important)

Bug fixes :

* this update adds the mmap_min_addr tunable and restriction checks to help prevent unprivileged users from creating new memory mappings below the minimum address. This can help prevent the exploitation of NULL pointer dereference bugs. Note that mmap_min_addr is set to zero (disabled) by default for backwards compatibility. (BZ#512642)

* a bridge reference count problem in IPv6 has been fixed. (BZ#457010)

* enforce null-termination of user-supplied arguments to setsockopt().
(BZ#505514)

* the gcc flag '-fno-delete-null-pointer-checks' was added to the kernel build options. This prevents gcc from optimizing out NULL pointer checks after the first use of a pointer. NULL pointer bugs are often exploited by attackers. Keeping these checks is a safety measure. (BZ#511185)

* a check has been added to the IPv4 code to make sure that rt is not NULL, to help prevent future bugs in functions that call ip_append_data() from being exploitable. (BZ#520300)

Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

Updated kernel packages that fix multiple 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.

Security fixes :

* a system with SELinux enforced was more permissive in allowing local users in the unconfined_t domain to map low memory areas even if the mmap_min_addr restriction was enabled. This could aid in the local exploitation of NULL pointer dereference bugs. (CVE-2009-2695, Important)

* a NULL pointer dereference flaw was found in the eCryptfs implementation in the Linux kernel. A local attacker could use this flaw to cause a local denial of service or escalate their privileges.
(CVE-2009-2908, Important)

* a flaw was found in the NFSv4 implementation. The kernel would do an unnecessary permission check after creating a file. This check would usually fail and leave the file with the permission bits set to random values. Note: This is a server-side only issue. (CVE-2009-3286, Important)

* a NULL pointer dereference flaw was found in each of the following functions in the Linux kernel: pipe_read_open(), pipe_write_open(), and pipe_rdwr_open(). When the mutex lock is not held, the i_pipe pointer could be released by other processes before it is used to update the pipe's reader and writer counters. This could lead to a local denial of service or privilege escalation. (CVE-2009-3547, Important)

* a flaw was found in the Realtek r8169 Ethernet driver in the Linux kernel. pci_unmap_single() presented a memory leak that could lead to IOMMU space exhaustion and a system crash. An attacker on the local network could abuse this flaw by using jumbo frames for large amounts of network traffic. (CVE-2009-3613, Important)

* missing initialization flaws were found in the Linux kernel. Padding data in several core network structures was not initialized properly before being sent to user-space. These flaws could lead to information leaks. (CVE-2009-3228, Moderate)

Bug fixes :

* with network bonding in the 'balance-tlb' or 'balance-alb' mode, the primary setting for the primary slave device was lost when said device was brought down. Bringing the slave back up did not restore the primary setting. (BZ#517971)

* some faulty serial device hardware caused systems running the kernel-xen kernel to take a very long time to boot. (BZ#524153)

* a caching bug in nfs_readdir() may have caused NFS clients to see duplicate files or not see all files in a directory. (BZ#526960)

* the RHSA-2009:1243 update removed the mpt_msi_enable option, preventing certain scripts from running. This update adds the option back. (BZ#526963)

* an iptables rule with the recent module and a hit count value greater than the ip_pkt_list_tot parameter (the default is 20), did not have any effect over packets, as the hit count could not be reached. (BZ#527434)

* a check has been added to the IPv4 code to make sure that rt is not NULL, to help prevent future bugs in functions that call ip_append_data() from being exploitable. (BZ#527436)

* a kernel panic occurred in certain conditions after reconfiguring a tape drive's block size. (BZ#528133)

* when using the Linux Virtual Server (LVS) in a master and backup configuration, and propagating active connections on the master to the backup, the connection timeout value on the backup was hard-coded to 180 seconds, meaning connection information on the backup was soon lost. This could prevent the successful failover of connections. The timeout value can now be set via 'ipvsadm --set'. (BZ#528645)

* a bug in nfs4_do_open_expired() could have caused the reclaimer thread on an NFSv4 client to enter an infinite loop. (BZ#529162)

* MSI interrupts may not have been delivered for r8169 based network cards that have MSI interrupts enabled. This bug only affected certain systems. (BZ#529366)

Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

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

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.

This update fixes the following security issues :

* a NULL pointer dereference flaw was found in each of the following functions in the Linux kernel: pipe_read_open(), pipe_write_open(), and pipe_rdwr_open(). When the mutex lock is not held, the i_pipe pointer could be released by other processes before it is used to update the pipe's reader and writer counters. This could lead to a local denial of service or privilege escalation. (CVE-2009-3547, Important)

Users should upgrade to these updated packages, which contain a backported patch to correct these issues. The system must be rebooted for this update to take effect.

NOTE: This kernel update marks the final planned kernel security update for the 2.6.24 kernel in the Debian release 'etch'. Although security support for 'etch' officially ended on Feburary 15th, 2010, this update was already in preparation before that date.

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

  - CVE-2009-2691     Steve Beattie and Kees Cook reported an information leak     in the maps and smaps files available under /proc. Local     users may be able to read this data for setuid processes     while the ELF binary is being loaded.

  - CVE-2009-2695     Eric Paris provided several fixes to increase the     protection provided by the mmap_min_addr tunable against     NULL pointer dereference vulnerabilities.

  - CVE-2009-3080     Dave Jones reported an issue in the gdth SCSI driver. A     missing check for negative offsets in an ioctl call     could be exploited by local users to create a denial of     service or potentially gain elevated privileges.

  - CVE-2009-3726     Trond Myklebust reported an issue where a malicious NFS     server could cause a denial of service condition on its     clients by returning incorrect attributes during an open     call.

  - CVE-2009-3889     Joe Malicki discovered an issue in the megaraid_sas     driver. Insufficient permissions on the sysfs dbg_lvl     interface allow local users to modify the debug logging     behavior.

  - CVE-2009-4005     Roel Kluin discovered an issue in the hfc_usb driver, an     ISDN driver for Colognechip HFC-S USB chip. A potential     read overflow exists which may allow remote users to     cause a denial of service condition (oops).

  - CVE-2009-4020     Amerigo Wang discovered an issue in the HFS filesystem     that would allow a denial of service by a local user who     has sufficient privileges to mount a specially crafted     filesystem.

  - CVE-2009-4021     Anana V. Avati discovered an issue in the fuse     subsystem. If the system is sufficiently low on memory,     a local user can cause the kernel to dereference an     invalid pointer resulting in a denial of service (oops)     and potentially an escalation of privileges.

  - CVE-2009-4138     Jay Fenlason discovered an issue in the firewire stack     that allows local users to cause a denial of service     (oops or crash) by making a specially crafted ioctl     call.

  - CVE-2009-4308     Ted Ts'o discovered an issue in the ext4 filesystem that     allows local users to cause a denial of service (NULL     pointer dereference). For this to be exploitable, the     local user must have sufficient privileges to mount a     filesystem.

  - CVE-2009-4536 CVE-2009-4538     Fabian Yamaguchi reported issues in the e1000 and e1000e     drivers for Intel gigabit network adapters which allow     remote users to bypass packet filters using specially     crafted Ethernet frames.

  - CVE-2010-0003     Andi Kleen reported a defect which allows local users to     gain read access to memory reachable by the kernel when     the print-fatal-signals option is enabled. This option     is disabled by default.

  - CVE-2010-0007     Florian Westphal reported a lack of capability checking     in the ebtables netfilter subsystem. If the ebtables     module is loaded, local users can add and modify     ebtables rules.

  - CVE-2010-0291     Al Viro reported several issues with the mmap/mremap     system calls that allow local users to cause a denial of     service (system panic) or obtain elevated privileges.

  - CVE-2010-0410     Sebastian Krahmer discovered an issue in the netlink     connector subsystem that permits local users to allocate     large amounts of system memory resulting in a denial of     service (out of memory).

  - CVE-2010-0415     Ramon de Carvalho Valle discovered an issue in the     sys_move_pages interface, limited to amd64, ia64 and     powerpc64 flavors in Debian. Local users can exploit     this issue to cause a denial of service (system crash)     or gain access to sensitive kernel memory.

  - CVE-2010-0622     Jerome Marchand reported an issue in the futex subsystem     that allows a local user to force an invalid futex state     which results in a denial of service (oops).

Security fixes: - CVE-2009-2691: Information disclosure in proc filesystem - CVE-2009-2848: execve: must clear current->child_tid - CVE-2009-2849: md: NULL pointer dereference - CVE-2009-2847:
Information leak in do_sigaltstack Restore missing LIRC drivers, dropped in previous release. Backport upstream fixes that further improve the security of mmap of low addresses. (CVE-2009-2695)

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.

ID	Name	Product	Family	Severity
67955	Oracle Linux 3 : kernel (ELSA-2009-1550)	Nessus	Oracle Linux Local Security Checks	high
67952	Oracle Linux 4 : kernel (ELSA-2009-1541)	Nessus	Oracle Linux Local Security Checks	high
67070	CentOS 3 : kernel (CESA-2009:1550)	Nessus	CentOS Local Security Checks	high
67068	CentOS 5 : kernel (CESA-2009:1548)	Nessus	CentOS Local Security Checks	high
67067	CentOS 4 : kernel (CESA-2009:1541)	Nessus	CentOS Local Security Checks	high
44951	Debian DSA-2005-1 : linux-2.6.24 - privilege escalation/denial of service/sensitive memory leak	Nessus	Debian Local Security Checks	critical
42360	RHEL 3 : kernel (RHSA-2009:1550)	Nessus	Red Hat Local Security Checks	high
42358	RHEL 5 : kernel (RHSA-2009:1548)	Nessus	Red Hat Local Security Checks	high
40780	Fedora 11 : kernel-2.6.29.6-217.2.16.fc11 (2009-9044)	Nessus	Fedora Local Security Checks	high

Detections

Analytics

CVE-2009-2691

medium

Tenable Plugins

high

high

high

high

high

critical

high

high

high