The x86_assign_hw_event function in arch/x86/kernel/cpu/perf_event.c in the Performance Events subsystem in the Linux kernel before 2.6.39 does not properly calculate counter values, which allows local users to cause a denial of service (panic) via the perf program.

The remote Oracle Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2011-1350 advisory.

  - The tpm_open function in drivers/char/tpm/tpm.c in the Linux kernel before 2.6.39 does not initialize a     certain buffer, which allows local users to obtain potentially sensitive information from kernel memory     via unspecified vectors. (CVE-2011-1160)

  - Integer overflow in the agp_generic_insert_memory function in drivers/char/agp/generic.c in the Linux     kernel before 2.6.38.5 allows local users to gain privileges or cause a denial of service (system crash)     via a crafted AGPIOC_BIND agp_ioctl ioctl call. (CVE-2011-1745)

  - Multiple integer overflows in the (1) agp_allocate_memory and (2) agp_create_user_memory functions in     drivers/char/agp/generic.c in the Linux kernel before 2.6.38.5 allow local users to trigger buffer     overflows, and consequently cause a denial of service (system crash) or possibly have unspecified other     impact, via vectors related to calls that specify a large number of memory pages. (CVE-2011-1746)

  - Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in the eCryptfs subsystem in the Linux     kernel before 3.1 allows local users to bypass intended file permissions via a mount.ecryptfs_private     mount with a mismatched uid. (CVE-2011-1833)

  - The agp_generic_remove_memory function in drivers/char/agp/generic.c in the Linux kernel before 2.6.38.5     does not validate a certain start parameter, which allows local users to gain privileges or cause a denial     of service (system crash) via a crafted AGPIOC_UNBIND agp_ioctl ioctl call, a different vulnerability than     CVE-2011-1745. (CVE-2011-2022)

  - The add_del_listener function in kernel/taskstats.c in the Linux kernel 2.6.39.1 and earlier does not     prevent multiple registrations of exit handlers, which allows local users to cause a denial of service     (memory and CPU consumption), and bypass the OOM Killer, via a crafted application. (CVE-2011-2484)

  - Integer overflow in the vma_to_resize function in mm/mremap.c in the Linux kernel before 2.6.39 allows     local users to cause a denial of service (BUG_ON and system crash) via a crafted mremap system call that     expands a memory mapping. (CVE-2011-2496)

  - The x86_assign_hw_event function in arch/x86/kernel/cpu/perf_event.c in the Performance Events subsystem     in the Linux kernel before 2.6.39 does not properly calculate counter values, which allows local users to     cause a denial of service (panic) via the perf program. (CVE-2011-2521)

  - The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel before 2.6.39.4, when     Generic Receive Offload (GRO) is enabled, resets certain fields in incorrect situations, which allows     remote attackers to cause a denial of service (system crash) via crafted network traffic. (CVE-2011-2723)

  - net/packet/af_packet.c in the Linux kernel before 2.6.39.3 does not properly restrict user-space access to     certain packet data structures associated with VLAN Tag Control Information, which allows local users to     obtain potentially sensitive information via a crafted application. (CVE-2011-2898)

  - The Performance Events subsystem in the Linux kernel before 3.1 does not properly handle event overflows     associated with PERF_COUNT_SW_CPU_CLOCK events, which allows local users to cause a denial of service     (system hang) via a crafted application. (CVE-2011-2918)

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

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

This update fixes the following security issues :

  - Flaws in the AGPGART driver implementation when handling     certain IOCTL commands could allow a local user to cause     a denial of service or escalate their privileges.
    (CVE-2011-1745, CVE-2011-2022, Important)

  - An integer overflow flaw in agp_allocate_memory() could     allow a local user to cause a denial of service or     escalate their privileges. (CVE-2011-1746, Important)

  - A race condition flaw was found in the Linux kernel's     eCryptfs implementation. A local attacker could use the     mount.ecryptfs_private utility to mount (and then     access) a directory they would otherwise not have access     to. Note: To correct this issue, a previous     ecryptfs-utils update, which provides the user-space     part of the fix, must also be installed. (CVE-2011-1833,     Moderate)

  - A denial of service flaw was found in the way the     taskstats subsystem handled the registration of process     exit handlers. A local, unprivileged user could register     an unlimited amount of these handlers, leading to     excessive CPU time and memory use. (CVE-2011-2484,     Moderate)

  - A flaw was found in the way mapping expansions were     handled. A local, unprivileged user could use this flaw     to cause a wrapping condition, triggering a denial of     service. (CVE-2011-2496, Moderate)

  - A flaw was found in the Linux kernel's Performance     Events implementation. It could falsely lead the NMI     (Non-Maskable Interrupt) Watchdog to detect a lockup and     panic the system. A local, unprivileged user could use     this flaw to cause a denial of service (kernel panic)     using the perf tool. (CVE-2011-2521, Moderate)

  - A flaw in skb_gro_header_slow() in the Linux kernel     could lead to GRO (Generic Receive Offload) fields being     left in an inconsistent state. An attacker on the local     network could use this flaw to trigger a denial of     service. GRO is enabled by default in all network     drivers that support it. (CVE-2011-2723, Moderate)

  - A flaw was found in the way the Linux kernel's     Performance Events implementation handled     PERF_COUNT_SW_CPU_CLOCK counter overflow. A local,     unprivileged user could use this flaw to cause a denial     of service. (CVE-2011-2918, Moderate)

  - A flaw was found in the Linux kernel's Trusted Platform     Module (TPM) implementation. A local, unprivileged user     could use this flaw to leak information to user-space.
    (CVE-2011-1160, Low)

  - Flaws were found in the tpacket_rcv() and     packet_recvmsg() functions in the Linux kernel. A local,     unprivileged user could use these flaws to leak     information to user-space. (CVE-2011-2898, Low)

This update also fixes various bugs and adds one enhancement.
Documentation for these changes will be available shortly from the Technical Notes document linked to in the References section.

Users should upgrade to these updated packages, which contain backported patches to correct these issues, and fix the bugs and add the enhancement noted in the Technical Notes. The system must be rebooted for this update to take effect.

The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2011:1350 advisory.

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

    This update fixes the following security issues:

    * Flaws in the AGPGART driver implementation when handling certain IOCTL     commands could allow a local user to cause a denial of service or escalate     their privileges. (CVE-2011-1745, CVE-2011-2022, Important)

    * An integer overflow flaw in agp_allocate_memory() could allow a local     user to cause a denial of service or escalate their privileges.
    (CVE-2011-1746, Important)

    * A race condition flaw was found in the Linux kernel's eCryptfs     implementation. A local attacker could use the mount.ecryptfs_private     utility to mount (and then access) a directory they would otherwise not     have access to. Note: To correct this issue, the RHSA-2011:1241     ecryptfs-utils update, which provides the user-space part of the fix, must     also be installed. (CVE-2011-1833, Moderate)

    * A denial of service flaw was found in the way the taskstats subsystem     handled the registration of process exit handlers. A local, unprivileged     user could register an unlimited amount of these handlers, leading to     excessive CPU time and memory use. (CVE-2011-2484, Moderate)

    * A flaw was found in the way mapping expansions were handled. A local,     unprivileged user could use this flaw to cause a wrapping condition,     triggering a denial of service. (CVE-2011-2496, Moderate)

    * A flaw was found in the Linux kernel's Performance Events implementation.
    It could falsely lead the NMI (Non-Maskable Interrupt) Watchdog to detect a     lockup and panic the system. A local, unprivileged user could use this flaw     to cause a denial of service (kernel panic) using the perf tool.
    (CVE-2011-2521, Moderate)

    * A flaw in skb_gro_header_slow() in the Linux kernel could lead to GRO     (Generic Receive Offload) fields being left in an inconsistent state. An     attacker on the local network could use this flaw to trigger a denial of     service. GRO is enabled by default in all network drivers that support it.
    (CVE-2011-2723, Moderate)

    * A flaw was found in the way the Linux kernel's Performance Events     implementation handled PERF_COUNT_SW_CPU_CLOCK counter overflow. A local,     unprivileged user could use this flaw to cause a denial of service.
    (CVE-2011-2918, Moderate)

    * A flaw was found in the Linux kernel's Trusted Platform Module (TPM)     implementation. A local, unprivileged user could use this flaw to leak     information to user-space. (CVE-2011-1160, Low)

    * Flaws were found in the tpacket_rcv() and packet_recvmsg() functions in     the Linux kernel. A local, unprivileged user could use these flaws to leak     information to user-space. (CVE-2011-2898, Low)

    Red Hat would like to thank Vasiliy Kulikov of Openwall for reporting     CVE-2011-1745, CVE-2011-2022, CVE-2011-1746, and CVE-2011-2484; the Ubuntu     Security Team for reporting CVE-2011-1833; Robert Swiecki for reporting     CVE-2011-2496; Li Yu for reporting CVE-2011-2521; Brent Meshier for     reporting CVE-2011-2723; and Peter Huewe for reporting CVE-2011-1160. The     Ubuntu Security Team acknowledges Vasiliy Kulikov of Openwall and Dan     Rosenberg as the original reporters of CVE-2011-1833.

    This update also fixes various bugs and adds one enhancement. Documentation     for these changes will be available shortly from the Technical Notes     document linked to in the References section.

    Users should upgrade to these updated packages, which contain backported     patches to correct these issues, and fix the bugs and add the enhancement     noted in the Technical Notes. The system must be rebooted for this update     to take effect.

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.

ID	Name	Product	Family	Severity
68364	Oracle Linux 6 : kernel (ELSA-2011-1350)	Nessus	Oracle Linux Local Security Checks	medium
61148	Scientific Linux Security Update : kernel on SL6.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	medium
56404	RHEL 6 : kernel (RHSA-2011:1350)	Nessus	Red Hat Local Security Checks	medium

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CVE-2011-2521

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Tenable Plugins

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