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. ========================================================================= Ubuntu Security Notice USN-3742-1 August 14, 2018 linux vulnerabilities ========================================================================= A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 14.04 LTS Summary: Several security issues were fixed in the Linux kernel. 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 14.04 LTS: linux-image-3.13.0-155-generic 3.13.0-155.205 linux-image-3.13.0-155-generic-lpae 3.13.0-155.205 linux-image-3.13.0-155-lowlatency 3.13.0-155.205 linux-image-3.13.0-155-powerpc-e500 3.13.0-155.205 linux-image-3.13.0-155-powerpc-e500mc 3.13.0-155.205 linux-image-3.13.0-155-powerpc-smp 3.13.0-155.205 linux-image-3.13.0-155-powerpc64-emb 3.13.0-155.205 linux-image-3.13.0-155-powerpc64-smp 3.13.0-155.205 linux-image-generic 3.13.0.155.165 linux-image-generic-lpae 3.13.0.155.165 linux-image-lowlatency 3.13.0.155.165 linux-image-powerpc-e500 3.13.0.155.165 linux-image-powerpc-e500mc 3.13.0.155.165 linux-image-powerpc-smp 3.13.0.155.165 linux-image-powerpc64-emb 3.13.0.155.165 linux-image-powerpc64-smp 3.13.0.155.165 Please note that the recommended mitigation for CVE-2018-3646 involves updating processor microcode in addition to updating the kernel; however, the kernel includes a fallback for processors that have not received microcode updates. 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. Description: The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Bug Fix(es): * The kernel-rt packages have been upgraded to the 3.10.0-693.43.1 source tree, which provides a number of bug fixes over the previous version. (BZ#1632422) 4. This is mitigated by reducing the default limits on memory usage for incomplete fragmented packets. The same mitigation can be achieved without the need to reboot, by setting the sysctls: net.ipv4.ipfrag_high_thresh = 262144 net.ipv6.ip6frag_high_thresh = 262144 net.ipv4.ipfrag_low_thresh = 196608 net.ipv6.ip6frag_low_thresh = 196608 The default values may still be increased by local configuration if necessary. For the stable distribution (stretch), this problem has been fixed in version 4.9.110-3+deb9u2. For the detailed security status of linux please refer to its security tracker page at: https://security-tracker.debian.org/tracker/linux Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/ Mailing list: debian-security-announce@lists.debian.org -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEERkRAmAjBceBVMd3uBUy48xNDz0QFAltzSylfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldDQ2 NDQ0MDk4MDhDMTcxRTA1NTMxRERFRTA1NENCOEYzMTM0M0NGNDQACgkQBUy48xND z0RaQQ//ZmbZqbqzS25ZDtEN7fJbInoznmfFiXHYCS9/GNEID3ODvPEn34omQ+Tj HJHroMWFsXROIaViHvJ2mZB3dpgv+ge1huvqXFTh+VrnQxvmdzzNy0UiDUH3B7jU BnbI7IS5x2dBC4cY+5vJ1fn0mWnvh/Bg9D+HEce3mmz9f/bTmXXiwPosyCM0KnzC R8aq73EU61A+IYJd+otICU6jZk+4IdgZRhW6q8F5OgHrnBryr0Xem8hSeL4Nkv3y aLX2Ca20eAgfeGo/SAHmG+FfJLR6dG8frz1k8HsKWNW16O8AC6lDbRC1+teK1e43 6GoIjfU9fBy3Cc35I1JQ85cfzfDLaETQ6IQ23o9SUP6qh8QKtUYDIU2sEDAThmrA IeoJsscGUvRMOx/XzuW8xN6rgbU+uNp8NIYXonZjy+U28dGp11obq3ka02railwj VEhm3YPIddeySofS0tZuBJ1XKL1/a5voLQ9GEBk+wq10DPdfYvSmIXxVR/FOfYy5 mLLTdtHINomfeihEI9AOWqq7w5bVIIidWB2a5FJiBZKWW1OdiNRHlD4hNMCR5xRv vK2PPXYcCxBuO4mdcnYydDcmrDvD22b6AhN1sm8FqUkWSXQbRoHNan95A8KbgZw0 Rk68oRCEFKcScB67ZhK2hUue7hZhkz52MlbS7pJgBPSuKrVsZtw= =WPm5 -----END PGP SIGNATURE----- . (BZ#1625330) 4. (BZ#1629634) 4. -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 ===================================================================== Red Hat Security Advisory Synopsis: Important: kernel security and bug fix update Advisory ID: RHSA-2018:3590-01 Product: Red Hat Enterprise Linux Advisory URL: https://access.redhat.com/errata/RHSA-2018:3590 Issue date: 2018-11-13 CVE Names: CVE-2017-18344 CVE-2018-5391 CVE-2018-10675 CVE-2018-14634 ===================================================================== 1. Summary: An update for kernel is now available for Red Hat Enterprise Linux 7.2 Advanced Update Support, Red Hat Enterprise Linux 7.2 Telco Extended Update Support, and Red Hat Enterprise Linux 7.2 Update Services for SAP Solutions. 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. 7.2) - noarch, x86_64 Red Hat Enterprise Linux Server E4S (v. 7.2) - noarch, x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 7.2) - x86_64 Red Hat Enterprise Linux Server Optional E4S (v. 7.2) - x86_64 Red Hat Enterprise Linux Server Optional TUS (v. 7.2) - x86_64 Red Hat Enterprise Linux Server TUS (v. 7.2) - 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 FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. (CVE-2018-5391) * kernel: out-of-bounds access in the show_timer function in kernel/time/posix-timers.c (CVE-2017-18344) * 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-2018-5391 and Qualys Research Labs for reporting CVE-2018-14634. Bug Fix(es): * 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#1629565) * Previously, a packet was missing the User Datagram Protocol (UDP) payload checksum during a full checksum computation, if the hardware checksum was not applied. As a consequence, a packet with an incorrect checksum was dropped by a peer. With this update, the kernel includes the UDP payload checksum during the full checksum computation. As a result, the checksum is computed correctly and the packet can be received by the peer. (BZ#1635792) * Previously, a transform lookup through the xfrm framework could be performed on an already transformed destination cache entry (dst_entry). When using User Datagram Protocol (UDP) over IPv6 with a connected socket in conjunction with Internet Protocol Security (IPsec) in Encapsulating Security Payload (ESP) transport mode. As a consequence, invalid IPv6 fragments transmitted from the host or the kernel occasionally terminated unexpectedly due to a socket buffer (SKB) underrun. With this update, the xfrm lookup on an already transformed dst_entry is not possible. As a result, using UDP iperf utility over IPv6 ESP no longer causes invalid IPv6 fragment transmissions or a kernel panic. (BZ#1639586) 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 1609664 - CVE-2018-5391 kernel: IP fragments with random offsets allow a remote denial of service (FragmentSmack) 1610958 - CVE-2017-18344 kernel: out-of-bounds access in the show_timer function in kernel/time/posix-timers.c 1624498 - CVE-2018-14634 kernel: Integer overflow in Linux's create_elf_tables function 6. Package List: Red Hat Enterprise Linux Server AUS (v. 7.2): Source: kernel-3.10.0-327.76.1.el7.src.rpm noarch: kernel-abi-whitelists-3.10.0-327.76.1.el7.noarch.rpm kernel-doc-3.10.0-327.76.1.el7.noarch.rpm x86_64: kernel-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-devel-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.76.1.el7.x86_64.rpm kernel-devel-3.10.0-327.76.1.el7.x86_64.rpm kernel-headers-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-libs-3.10.0-327.76.1.el7.x86_64.rpm perf-3.10.0-327.76.1.el7.x86_64.rpm perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm python-perf-3.10.0-327.76.1.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm Red Hat Enterprise Linux Server E4S (v. 7.2): Source: kernel-3.10.0-327.76.1.el7.src.rpm noarch: kernel-abi-whitelists-3.10.0-327.76.1.el7.noarch.rpm kernel-doc-3.10.0-327.76.1.el7.noarch.rpm x86_64: kernel-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-devel-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.76.1.el7.x86_64.rpm kernel-devel-3.10.0-327.76.1.el7.x86_64.rpm kernel-headers-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-libs-3.10.0-327.76.1.el7.x86_64.rpm perf-3.10.0-327.76.1.el7.x86_64.rpm perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm python-perf-3.10.0-327.76.1.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm Red Hat Enterprise Linux Server TUS (v. 7.2): Source: kernel-3.10.0-327.76.1.el7.src.rpm noarch: kernel-abi-whitelists-3.10.0-327.76.1.el7.noarch.rpm kernel-doc-3.10.0-327.76.1.el7.noarch.rpm x86_64: kernel-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debug-devel-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.76.1.el7.x86_64.rpm kernel-devel-3.10.0-327.76.1.el7.x86_64.rpm kernel-headers-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-libs-3.10.0-327.76.1.el7.x86_64.rpm perf-3.10.0-327.76.1.el7.x86_64.rpm perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm python-perf-3.10.0-327.76.1.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm Red Hat Enterprise Linux Server Optional AUS (v. 7.2): x86_64: kernel-debug-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-libs-devel-3.10.0-327.76.1.el7.x86_64.rpm perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm Red Hat Enterprise Linux Server Optional E4S (v. 7.2): x86_64: kernel-debug-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-libs-devel-3.10.0-327.76.1.el7.x86_64.rpm perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm Red Hat Enterprise Linux Server Optional TUS (v. 7.2): x86_64: kernel-debug-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm kernel-tools-libs-devel-3.10.0-327.76.1.el7.x86_64.rpm perf-debuginfo-3.10.0-327.76.1.el7.x86_64.rpm python-perf-debuginfo-3.10.0-327.76.1.el7.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-2017-18344 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 iQIVAwUBW+sPDtzjgjWX9erEAQhm3BAAhxwzb8zJTfl0zFY/r9KUzkAdLXY4w39X BgJrVPyl7f6krvQ17HE95Poqz/iUhMOZAweypQXHMRKkmfMTYiLHlKpdIusou2xy y1ZzB1uloI4j2zMdTDRP5yZz06r/NP5A05pLZDA02iR5b07ALLYb5hcL5oBnpQXp 9Xp31qb7TCP+jWtCO1Ot+9GJ3chMNvpYqH0OkGTpq/G7PxGrhIzB6v4p6N5OntD9 5CIebREaGBWn9ViWiUHcthgg+PN2iS2/5ST82g/Jss/WmVVZSiVbayob6/MNQPnb M29VHOmJ6pf5dERNpSqrJrBXeDYCMA6HHD+RT9SmiuQQ8gQ2Rzjy7K97Nn++6x7O nclOTmB7hQZtl0WhgC3xuwtslXGpe9jKSzql03ijTvJRQrczgVWiBS+tpfVAJprV ma2Kchf5ivctaXZ/R62JMyTvNf6HCVdvBNvSNET52ol3PkdpJK7V7mg+H64Mqdrl cBTUDBHHYYWMJted9pHWq7tPs0vy1h9aoFqNdlak5jwr169vldlZMRBbhtvz+OXj V/o+IClbY9UUfibaXDoX7qufeVikW1KQ4L+VhRj3RzXNsu2A8FUAcN7za5Qv5HIe LiC42C+pjvHqS/9gNpBakzKv6nPldWZIfPEuF4zewizBxlTXHPE1ln1hAWKjqVTs 6QJ1Zh7jeUY= =8JOQ -----END PGP SIGNATURE----- -- RHSA-announce mailing list RHSA-announce@redhat.com https://www.redhat.com/mailman/listinfo/rhsa-announce . 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. (BZ#1629632) 4. 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. (BZ#1629633) 4. 7.3) - ppc64, ppc64le, x86_64 3. 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. Consequently, the node was not available. This update fixes an irq latency source in memory compaction. (BZ#1596281) * Previously, the kernel source code was missing support to report the Speculative Store Bypass Disable (SSBD) vulnerability status on IBM Power Systems and the little-endian variants of IBM Power Systems. As a consequence, the /sys/devices/system/cpu/vulnerabilities/spec_store_bypass file incorrectly reported "Not affected" on both CPU architectures. 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". As a consequence, the VMs sometimes became unresponsive when booting. This update applies an upstream patch to avoid early microcode update when running under a hypervisor. (BZ#1618388) 4

AFFECTED PRODUCTS