RHEL 6 : MRG (RHSA-2018:2789)

2018-09-28T00:00:00
ID REDHAT-RHSA-2018-2789.NASL
Type nessus
Reporter This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-06-02T00:00:00

Description

An update for kernel-rt is now available for Red Hat Enterprise MRG 2.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es) :

  • A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses. (CVE-2018-5390)

Red Hat would like to thank Juha-Matti Tilli (Aalto University - Department of Communications and Networking and Nokia Bell Labs) for reporting this issue.

Bug Fix(es) :

  • The kernel-rt packages have been upgraded to the 3.10.0-693.39.1 source tree, which provides a number of bug fixes over the previous version. (BZ# 1616431)

  • Previously, preemption was enabled too early after a context switch. If a task was migrated to another CPU after a context switch, a mismatch between CPU and runqueue during load balancing sometimes occurred. Consequently, a runnable task on an idle CPU failed to run, and the operating system became unresponsive. This update disables preemption in the schedule_tail() function. As a result, CPU migration during post-schedule processing no longer occurs, which prevents the above mismatch. The operating system no longer hangs due to this bug. (BZ#1618466)

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:2789. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(117816);
  script_version("1.8");
  script_cvs_date("Date: 2019/10/24 15:35:45");

  script_cve_id("CVE-2018-5390");
  script_xref(name:"RHSA", value:"2018:2789");

  script_name(english:"RHEL 6 : MRG (RHSA-2018:2789)");
  script_summary(english:"Checks the rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Red Hat host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"An update for kernel-rt is now available for Red Hat Enterprise MRG 2.

Red Hat Product Security has rated this update as having a security
impact of Important. A Common Vulnerability Scoring System (CVSS) base
score, which gives a detailed severity rating, is available for each
vulnerability from the CVE link(s) in the References section.

The kernel-rt packages provide the Real Time Linux Kernel, which
enables fine-tuning for systems with extremely high determinism
requirements.

Security Fix(es) :

* A flaw named SegmentSmack was found in the way the Linux kernel
handled specially crafted TCP packets. A remote attacker could use
this flaw to trigger time and calculation expensive calls to
tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by
sending specially modified packets within ongoing TCP sessions which
could lead to a CPU saturation and hence a denial of service on the
system. Maintaining the denial of service condition requires
continuous two-way TCP sessions to a reachable open port, thus the
attacks cannot be performed using spoofed IP addresses.
(CVE-2018-5390)

Red Hat would like to thank Juha-Matti Tilli (Aalto University -
Department of Communications and Networking and Nokia Bell Labs) for
reporting this issue.

Bug Fix(es) :

* The kernel-rt packages have been upgraded to the 3.10.0-693.39.1
source tree, which provides a number of bug fixes over the previous
version. (BZ# 1616431)

* Previously, preemption was enabled too early after a context switch.
If a task was migrated to another CPU after a context switch, a
mismatch between CPU and runqueue during load balancing sometimes
occurred. Consequently, a runnable task on an idle CPU failed to run,
and the operating system became unresponsive. This update disables
preemption in the schedule_tail() function. As a result, CPU migration
during post-schedule processing no longer occurs, which prevents the
above mismatch. The operating system no longer hangs due to this bug.
(BZ#1618466)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2018:2789"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-5390"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo-common-x86_64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-firmware");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/08/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/28");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Red Hat Local Security Checks");

  script_dependencies("ssh_get_info.nasl", "linux_alt_patch_detect.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("rpm.inc");
include("ksplice.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Red Hat" >!< release) audit(AUDIT_OS_NOT, "Red Hat");
os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Red Hat");
os_ver = os_ver[1];
if (! preg(pattern:"^6([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 6.x", "Red Hat " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "s390" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Red Hat", cpu);

if (get_one_kb_item("Host/ksplice/kernel-cves"))
{
  rm_kb_item(name:"Host/uptrack-uname-r");
  cve_list = make_list("CVE-2018-5390");
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "KSplice hotfix for RHSA-2018:2789");
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}

yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
if (!empty_or_null(yum_updateinfo)) 
{
  rhsa = "RHSA-2018:2789";
  yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
  if (!empty_or_null(yum_report))
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : yum_report 
    );
    exit(0);
  }
  else
  {
    audit_message = "affected by Red Hat security advisory " + rhsa;
    audit(AUDIT_OS_NOT, audit_message);
  }
}
else
{
  flag = 0;

  if (! (rpm_exists(release:"RHEL6", rpm:"mrg-release"))) audit(AUDIT_PACKAGE_NOT_INSTALLED, "MRG");

  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debug-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debug-debuginfo-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debug-devel-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debuginfo-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debuginfo-common-x86_64-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-devel-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", reference:"kernel-rt-doc-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", reference:"kernel-rt-firmware-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-trace-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-trace-debuginfo-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-trace-devel-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-vanilla-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-vanilla-debuginfo-3.10.0-693.39.1.rt56.629.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-vanilla-devel-3.10.0-693.39.1.rt56.629.el6")) flag++;

  if (flag)
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get() + redhat_report_package_caveat()
    );
    exit(0);
  }
  else
  {
    tested = pkg_tests_get();
    if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
    else audit(AUDIT_PACKAGE_NOT_INSTALLED, "kernel-rt / kernel-rt-debug / kernel-rt-debug-debuginfo / etc");
  }
}