ID

VAR-201809-1153

CVE

CVE-2018-5391

TITLE

Linux kernel IP fragment re-assembly vulnerable to denial of service

DESCRIPTION

The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size. Linux Kernel is prone to a remote denial-of-service vulnerability. An attacker can exploit this issue to cause a denial-of-service condition. Description: The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. (BZ#1632422) 4. (BZ#1625330) 4. 6.7) - i386, ppc64, s390x, x86_64 3. Bug Fix(es): * Previously, the kernel source code lacked support to report the Speculative Store Bypass Disable (SSBD) vulnerability status on IBM Power Systems. As a consequence, the /sys/devices/system/cpu/vulnerabilities/spec_store_bypass file incorrectly reported "Not affected". This fix updates the kernel source code to properly report the SSBD status either as "Vulnerable" or "Mitigation: Kernel entry/exit barrier (TYPE)", where TYPE is one of "eieio", "hwsync", "fallback", or "unknown". (BZ#1629634) 4. ========================================================================== Ubuntu Security Notice USN-3742-3 August 21, 2018 linux-lts-trusty regressions ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 12.04 ESM Summary: USN-3742-2 introduced regressions in the Linux Hardware Enablement (HWE) kernel for Ubuntu 12.04 ESM. Software Description: - linux-lts-trusty: Linux hardware enablement kernel from Trusty for Precise ESM Details: USN-3742-2 introduced mitigations in the Linux Hardware Enablement (HWE) kernel for Ubuntu 12.04 ESM to address L1 Terminal Fault (L1TF) vulnerabilities (CVE-2018-3620, CVE-2018-3646). Unfortunately, the update introduced regressions that caused kernel panics when booting in some environments as well as preventing Java applications from starting. We apologize for the inconvenience. Original advisory details: It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local attacker in a guest virtual machine could use this to expose sensitive information (memory from other guests or the host OS). (CVE-2018-3646) It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local attacker could use this to expose sensitive information (memory from the kernel or other processes). (CVE-2018-3620) Andrey Konovalov discovered an out-of-bounds read in the POSIX timers subsystem in the Linux kernel. (CVE-2018-5391) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 12.04 ESM: linux-image-3.13.0-156-generic 3.13.0-156.206~precise1 linux-image-3.13.0-156-generic-lpae 3.13.0-156.206~precise1 linux-image-generic-lpae-lts-trusty 3.13.0.156.146 linux-image-generic-lts-trusty 3.13.0.156.146 After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well. 6.5) - x86_64 3. Bug Fix(es): * Previously, invalid headers in the sk_buff struct led to an indefinite loop in the tcp_collapse() function. As a consequence, the system became unresponsive. This update backports the upstream changes that remove the problematic code in tcp_collapse(). (BZ#1629632) 4. Bug Fix(es): These updated kernel packages include also numerous bug fixes. Space precludes documenting all of the bug fixes in this advisory. See the descriptions in the related Knowledge Article: https://access.redhat.com/articles/3674801 4. -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 ==================================================================== Red Hat Security Advisory Synopsis: Important: kernel security and bug fix update Advisory ID: RHSA-2018:2924-01 Product: Red Hat Enterprise Linux Advisory URL: https://access.redhat.com/errata/RHSA-2018:2924 Issue date: 2018-10-16 CVE Names: CVE-2018-5390 CVE-2018-5391 CVE-2018-10675 CVE-2018-14634 ==================================================================== 1. Summary: An update for kernel is now available for Red Hat Enterprise Linux 6.6 Advanced Update Support and Red Hat Enterprise Linux 6.6 Telco Extended Update Support. 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. 2. Relevant releases/architectures: Red Hat Enterprise Linux Server AUS (v. 6.6) - noarch, x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 6.6) - x86_64 Red Hat Enterprise Linux Server Optional TUS (v. 6.6) - x86_64 Red Hat Enterprise Linux Server TUS (v. 6.6) - noarch, x86_64 3. Description: The kernel packages contain the Linux kernel, the core of any Linux operating system. 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) * A flaw named FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. (CVE-2018-5391) * kernel: mm: use-after-free in do_get_mempolicy function allows local DoS or other unspecified impact (CVE-2018-10675) * kernel: Integer overflow in Linux's create_elf_tables function (CVE-2018-14634) For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section. Red Hat would like to thank Juha-Matti Tilli (Aalto University - Department of Communications and Networking and Nokia Bell Labs) for reporting CVE-2018-5390 and CVE-2018-5391 and Qualys Research Labs for reporting CVE-2018-14634. Bug Fix(es): * After updating the system to prevent the L1 Terminal Fault (L1TF) vulnerability, only one thread was detected on systems that offer processing of two threads on a single processor core. With this update, the "__max_smt_threads()" function has been fixed. As a result, both threads are now detected correctly in the described situation. (BZ#1625334) * Previously, a kernel panic occurred when the kernel tried to make an out of bound access to the array that describes the L1 Terminal Fault (L1TF) mitigation state on systems without Extended Page Tables (EPT) support. This update extends the array of mitigation states to cover all the states, which effectively prevents out of bound array access. Also, this update enables rejecting invalid, irrelevant values, that might be erroneously provided by the userspace. As a result, the kernel no longer panics in the described scenario. (BZ#1629633) 4. Solution: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. 5. Bugs fixed (https://bugzilla.redhat.com/): 1575065 - CVE-2018-10675 kernel: mm: use-after-free in do_get_mempolicy function allows local DoS or other unspecified impact 1601704 - CVE-2018-5390 kernel: TCP segments with random offsets allow a remote denial of service (SegmentSmack) 1609664 - CVE-2018-5391 kernel: IP fragments with random offsets allow a remote denial of service (FragmentSmack) 1624498 - CVE-2018-14634 kernel: Integer overflow in Linux's create_elf_tables function 6. Package List: Red Hat Enterprise Linux Server AUS (v. 6.6): Source: kernel-2.6.32-504.76.2.el6.src.rpm noarch: kernel-abi-whitelists-2.6.32-504.76.2.el6.noarch.rpm kernel-doc-2.6.32-504.76.2.el6.noarch.rpm kernel-firmware-2.6.32-504.76.2.el6.noarch.rpm x86_64: kernel-2.6.32-504.76.2.el6.x86_64.rpm kernel-debug-2.6.32-504.76.2.el6.x86_64.rpm kernel-debug-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debug-devel-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-504.76.2.el6.x86_64.rpm kernel-devel-2.6.32-504.76.2.el6.x86_64.rpm kernel-headers-2.6.32-504.76.2.el6.x86_64.rpm perf-2.6.32-504.76.2.el6.x86_64.rpm perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm Red Hat Enterprise Linux Server TUS (v. 6.6): Source: kernel-2.6.32-504.76.2.el6.src.rpm noarch: kernel-abi-whitelists-2.6.32-504.76.2.el6.noarch.rpm kernel-doc-2.6.32-504.76.2.el6.noarch.rpm kernel-firmware-2.6.32-504.76.2.el6.noarch.rpm x86_64: kernel-2.6.32-504.76.2.el6.x86_64.rpm kernel-debug-2.6.32-504.76.2.el6.x86_64.rpm kernel-debug-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debug-devel-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-504.76.2.el6.x86_64.rpm kernel-devel-2.6.32-504.76.2.el6.x86_64.rpm kernel-headers-2.6.32-504.76.2.el6.x86_64.rpm perf-2.6.32-504.76.2.el6.x86_64.rpm perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm Red Hat Enterprise Linux Server Optional AUS (v. 6.6): x86_64: kernel-debug-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-504.76.2.el6.x86_64.rpm perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm python-perf-2.6.32-504.76.2.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm Red Hat Enterprise Linux Server Optional TUS (v. 6.6): x86_64: kernel-debug-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-504.76.2.el6.x86_64.rpm perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm python-perf-2.6.32-504.76.2.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.76.2.el6.x86_64.rpm These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from https://access.redhat.com/security/team/key/ 7. References: https://access.redhat.com/security/cve/CVE-2018-5390 https://access.redhat.com/security/cve/CVE-2018-5391 https://access.redhat.com/security/cve/CVE-2018-10675 https://access.redhat.com/security/cve/CVE-2018-14634 https://access.redhat.com/security/updates/classification/#important https://access.redhat.com/articles/3553061 https://access.redhat.com/security/vulnerabilities/mutagen-astronomy 8. Contact: The Red Hat security contact is <secalert@redhat.com>. More contact details at https://access.redhat.com/security/team/contact/ Copyright 2018 Red Hat, Inc. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUBW8X6otzjgjWX9erEAQj5OQ/+O0GjLYqyc0dlDxIBFWYXEGkMxGpwpgR1 HpF5FKVo32x78i8M/mQXTEtnwJxfGH+ABkYUPmiJxfyhKuuNptNEg/rD02HRjuC5 GmZG8CEloGu8NGPu3CEEPrRpK2sqVf2F+KqM9MKjMr+++8DxwXy8eSOSDRI/yJyI /xQhUPPx7g+ZZuoXs5Fh6ckfuDIFwn3gT6tqmet59WcL5L1phr1grDyeP6NbrLLY UFEAbjs9x6TDnwbUM5DnDflBENhJElamSgClObp0UOa31FCI1okO8rW1qCL/HYhY z2avZB31qCwtCM/5nCg104+xKO3Bqz3QcCtkL4m7gRWmPvATpOUweI9ptYW69iwF 2Bmr+25h2yVLvfAhqVvCGnRqAdPoSBYoasZR94oF9ctjOu66uWdT7h12oiPlFEFh oZXfozGdb+HdX18/If/2vzPskuZ/EGwbOJn3IHSmuru2oIBHrIHZ5X3ke6gtHeIN Pby2IS10QpCng48r+278ifFkPyG0Y1XmalapBHPadpWy3htPQEr9YmGehEGiyKMz hgD8rss/D7HTS/o+FGE8sE9yjEWpCbUcPWu5u7Rw8chAut8GHVHAvCRgCcUK5puo rmse06Ba+bjUh3OucXsHmsk8VQ+STC4xt1cTbnDTd1xELrH8J+qv8fGV84sdEAaj K3wXCIrtY5U=osL7 -----END PGP SIGNATURE----- -- RHSA-announce mailing list RHSA-announce@redhat.com https://www.redhat.com/mailman/listinfo/rhsa-announce

AFFECTED PRODUCTS