ID

VAR-201511-0101

CVE

CVE-2015-8104

TITLE

Linux Kernel of KVM Subsystem and Xen Service disruption in (DoS) Vulnerabilities

DESCRIPTION

The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a denial of service (host OS panic or hang) by triggering many #DB (aka Debug) exceptions, related to svm.c. Linux Kernel is prone to a denial-of-service vulnerability. An attacker with a guest account can exploit this issue to cause an infinite loop in the host, denying service to legitimate users. -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ===================================================================== Red Hat Security Advisory Synopsis: Important: kernel security and bug fix update Advisory ID: RHSA-2016:0024-01 Product: Red Hat Enterprise Linux Advisory URL: https://rhn.redhat.com/errata/RHSA-2016-0024.html Issue date: 2016-01-12 CVE Names: CVE-2015-5307 CVE-2015-8104 ===================================================================== 1. Summary: Updated kernel packages that fix two security issues and several bugs are now available for Red Hat Enterprise Linux 6.6 Extended Update Support. Red Hat Product Security has rated this update as having Important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section. 2. Relevant releases/architectures: Red Hat Enterprise Linux Compute Node Optional EUS (v. 6.6) - x86_64 Red Hat Enterprise Linux HPC Node EUS (v. 6.6) - noarch, x86_64 Red Hat Enterprise Linux Server EUS (v. 6.6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional EUS (v. 6.6) - i386, ppc64, s390x, x86_64 3. * It was found that the x86 ISA (Instruction Set Architecture) is prone to a denial of service attack inside a virtualized environment in the form of an infinite loop in the microcode due to the way (sequential) delivering of benign exceptions such as #AC (alignment check exception) and #DB (debug exception) is handled. A privileged user inside a guest could use these flaws to create denial of service conditions on the host kernel. (CVE-2015-5307, CVE-2015-8104, Important) Red Hat would like to thank Ben Serebrin of Google Inc. for reporting the CVE-2015-5307 issue. This update also fixes the following bugs: * When doing TSO/GSO in the presence of VLAN headers on a macvtap device, the header offsets were incorrectly calculated. As a consequence, when 2 guests on the same host communicated over a guest configured VLAN, performance dropped to about 1 Mbps. A set of patches has been provided to fix this bug, and network performance with VLAN tags now works with optimal performance. (BZ#1215914) * Prior to this update, TSO acceleration features have been removed from the VLAN device which caused that VLAN performance on top of a virtio device was much lower than that of a virtio device itself. This update re-enables TSO acceleration features, and performance of VLAN devices on top of a virtio device has thus been restored. (BZ#1240988) * With an IPv6 address on a bond and a slave failover, Unsolicited Neighbor Advertisement (UNA) was previously sent using the link global IPv6 address as source address. The underlying source code has been patched, and, after the failover in bonding, UNA is sent using both the corresponding link IPv6 address and global IPv6 address of bond0 and bond0.vlan. (BZ#1258480) * Previously, Human Interface Device (HID) would run a report on an unaligned buffer, which could cause a page fault interrupt and an oops when the end of the report was read. This update fixes this bug by padding the end of the report with extra bytes, so the reading of the report never crosses a page boundary. As a result, a page fault and subsequent oops no longer occur. (BZ#1268202) * Inside hugetlb, region data structures were protected by a combination of a memory map semaphore and a single hugetlb instance mutex. However, a page-fault scalability improvement backported to the kernel on previous releases removed the single hugetlb instance mutex and introduced a new mutex table, making the locking combination insufficient, leading to possible race windows that could cause corruption and undefined behavior. The problem could be seen for example with software mapping or re-mapping hugetlb areas with concurrent threads reading/writing to same areas causing page faults. This update fixes the problem by introducing now a required spinlock to the region tracking functions for proper serialization. The problem only affects software using huge pages through hugetlb interface. (BZ#1274597) * Previously, VLAN stacked on the macvlan or macvtap device did not work for devices that implement and use VLAN filters. As a consequence, macvtap passthrough mode failed to transfer VLAN packets over the be2net driver. This update implements VLAN ndo calls to the macvlan driver to pass appropriate VLAN tag IDs to lower devices. As a result, macvtap transfers VLAN packets over be2net successfully. (BZ#1280205) All kernel users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect. 4. Solution: Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258 5. Bugs fixed (https://bugzilla.redhat.com/): 1277172 - CVE-2015-5307 virt: guest to host DoS by triggering an infinite loop in microcode via #AC exception 1278496 - CVE-2015-8104 virt: guest to host DoS by triggering an infinite loop in microcode via #DB exception 6. Package List: Red Hat Enterprise Linux HPC Node EUS (v. 6.6): Source: kernel-2.6.32-504.40.1.el6.src.rpm noarch: kernel-abi-whitelists-2.6.32-504.40.1.el6.noarch.rpm kernel-doc-2.6.32-504.40.1.el6.noarch.rpm kernel-firmware-2.6.32-504.40.1.el6.noarch.rpm x86_64: kernel-2.6.32-504.40.1.el6.x86_64.rpm kernel-debug-2.6.32-504.40.1.el6.x86_64.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debug-devel-2.6.32-504.40.1.el6.i686.rpm kernel-debug-devel-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-common-i686-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-common-x86_64-2.6.32-504.40.1.el6.x86_64.rpm kernel-devel-2.6.32-504.40.1.el6.x86_64.rpm kernel-headers-2.6.32-504.40.1.el6.x86_64.rpm perf-2.6.32-504.40.1.el6.x86_64.rpm perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm Red Hat Enterprise Linux Compute Node Optional EUS (v. 6.6): x86_64: kernel-debug-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-504.40.1.el6.x86_64.rpm perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm python-perf-2.6.32-504.40.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm Red Hat Enterprise Linux Server EUS (v. 6.6): Source: kernel-2.6.32-504.40.1.el6.src.rpm i386: kernel-2.6.32-504.40.1.el6.i686.rpm kernel-debug-2.6.32-504.40.1.el6.i686.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debug-devel-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-common-i686-2.6.32-504.40.1.el6.i686.rpm kernel-devel-2.6.32-504.40.1.el6.i686.rpm kernel-headers-2.6.32-504.40.1.el6.i686.rpm perf-2.6.32-504.40.1.el6.i686.rpm perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm noarch: kernel-abi-whitelists-2.6.32-504.40.1.el6.noarch.rpm kernel-doc-2.6.32-504.40.1.el6.noarch.rpm kernel-firmware-2.6.32-504.40.1.el6.noarch.rpm ppc64: kernel-2.6.32-504.40.1.el6.ppc64.rpm kernel-bootwrapper-2.6.32-504.40.1.el6.ppc64.rpm kernel-debug-2.6.32-504.40.1.el6.ppc64.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm kernel-debug-devel-2.6.32-504.40.1.el6.ppc64.rpm kernel-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm kernel-debuginfo-common-ppc64-2.6.32-504.40.1.el6.ppc64.rpm kernel-devel-2.6.32-504.40.1.el6.ppc64.rpm kernel-headers-2.6.32-504.40.1.el6.ppc64.rpm perf-2.6.32-504.40.1.el6.ppc64.rpm perf-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm s390x: kernel-2.6.32-504.40.1.el6.s390x.rpm kernel-debug-2.6.32-504.40.1.el6.s390x.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.s390x.rpm kernel-debug-devel-2.6.32-504.40.1.el6.s390x.rpm kernel-debuginfo-2.6.32-504.40.1.el6.s390x.rpm kernel-debuginfo-common-s390x-2.6.32-504.40.1.el6.s390x.rpm kernel-devel-2.6.32-504.40.1.el6.s390x.rpm kernel-headers-2.6.32-504.40.1.el6.s390x.rpm kernel-kdump-2.6.32-504.40.1.el6.s390x.rpm kernel-kdump-debuginfo-2.6.32-504.40.1.el6.s390x.rpm kernel-kdump-devel-2.6.32-504.40.1.el6.s390x.rpm perf-2.6.32-504.40.1.el6.s390x.rpm perf-debuginfo-2.6.32-504.40.1.el6.s390x.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.s390x.rpm x86_64: kernel-2.6.32-504.40.1.el6.x86_64.rpm kernel-debug-2.6.32-504.40.1.el6.x86_64.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debug-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debug-devel-2.6.32-504.40.1.el6.i686.rpm kernel-debug-devel-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-common-i686-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-common-x86_64-2.6.32-504.40.1.el6.x86_64.rpm kernel-devel-2.6.32-504.40.1.el6.x86_64.rpm kernel-headers-2.6.32-504.40.1.el6.x86_64.rpm perf-2.6.32-504.40.1.el6.x86_64.rpm perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm Red Hat Enterprise Linux Server Optional EUS (v. 6.6): i386: kernel-debug-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-2.6.32-504.40.1.el6.i686.rpm kernel-debuginfo-common-i686-2.6.32-504.40.1.el6.i686.rpm perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm python-perf-2.6.32-504.40.1.el6.i686.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.i686.rpm ppc64: kernel-debug-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm kernel-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm kernel-debuginfo-common-ppc64-2.6.32-504.40.1.el6.ppc64.rpm perf-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm python-perf-2.6.32-504.40.1.el6.ppc64.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.ppc64.rpm s390x: kernel-debug-debuginfo-2.6.32-504.40.1.el6.s390x.rpm kernel-debuginfo-2.6.32-504.40.1.el6.s390x.rpm kernel-debuginfo-common-s390x-2.6.32-504.40.1.el6.s390x.rpm kernel-kdump-debuginfo-2.6.32-504.40.1.el6.s390x.rpm perf-debuginfo-2.6.32-504.40.1.el6.s390x.rpm python-perf-2.6.32-504.40.1.el6.s390x.rpm python-perf-debuginfo-2.6.32-504.40.1.el6.s390x.rpm x86_64: kernel-debug-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm kernel-debuginfo-common-x86_64-2.6.32-504.40.1.el6.x86_64.rpm perf-debuginfo-2.6.32-504.40.1.el6.x86_64.rpm python-perf-2.6.32-504.40.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.40.1.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-2015-5307 https://access.redhat.com/security/cve/CVE-2015-8104 https://access.redhat.com/security/updates/classification/#important 8. Contact: The Red Hat security contact is <secalert@redhat.com>. More contact details at https://access.redhat.com/security/team/contact/ Copyright 2016 Red Hat, Inc. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iD8DBQFWlRlbXlSAg2UNWIIRAvimAKCP0NBarE2OqhzvNzvLKaBGVwd+PwCgne8S o4eKsHm6k54+KupMDbYhbEc= =Zcot -----END PGP SIGNATURE----- -- RHSA-announce mailing list RHSA-announce@redhat.com https://www.redhat.com/mailman/listinfo/rhsa-announce . Upstream support for the 4.1 release series has ended and since no information is available which would allow backports of isolated security fixes, security support for virtualbox in wheezy/oldstable needed to be ended as well. If you use virtualbox with externally procured VMs (e.g. through vagrant) we advise you to update to Debian jessie. CVE-2013-7446 Dmitry Vyukov discovered that a particular sequence of valid operations on local (AF_UNIX) sockets can result in a use-after-free. This may be used to cause a denial of service (crash) or possibly for privilege escalation. CVE-2015-7799 It was discovered that a user granted access to /dev/ppp can cause a denial of service (crash) by passing invalid parameters to the PPPIOCSMAXCID ioctl. This also applies to ISDN PPP device nodes. CVE-2015-7833 Sergej Schumilo, Hendrik Schwartke and Ralf Spenneberg discovered a flaw in the processing of certain USB device descriptors in the usbvision driver. An attacker with physical access to the system can use this flaw to crash the system. This was partly fixed by the changes listed in DSA 3396-1. CVE-2015-8104 Jan Beulich reported a guest to host denial-of-service flaw affecting the KVM hypervisor running on AMD processors. This leads to a panic of the host kernel. CVE-2015-8374 It was discovered that Btrfs did not correctly implement truncation of compressed inline extents. This could lead to an information leak, if a file is truncated and later made readable by other users. Additionally, it could cause data loss. This has been fixed for the stable distribution (jessie) only. CVE-2015-8543 It was discovered that a local user permitted to create raw sockets could cause a denial-of-service by specifying an invalid protocol number for the socket. The attacker must have the CAP_NET_RAW capability in their user namespace. This has been fixed for the stable distribution (jessie) only. For the oldstable distribution (wheezy), these problems have been fixed in version 3.2.73-2+deb7u1. In addition, this update contains several changes originally targeted for the upcoming Wheezy point release. For the stable distribution (jessie), these problems have been fixed in version 3.16.7-ckt20-1+deb8u1. In addition, this update contains several changes originally targeted for the upcoming Jessie point release. Content-Disposition: inline ============================================================================ Ubuntu Security Notice USN-2843-1 December 17, 2015 linux vulnerabilities ============================================================================ A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 15.10 Summary: Several security issues were fixed in the kernel. (CVE-2015-8104) =E9=83=AD=E6=B0=B8=E5=88=9A discovered that the ppp implementation in the Linux kernel did not ensure that certain slot numbers are valid. (CVE-2015-7799) Dmitry Vyukov discovered that the Linux kernel's keyring handler attempted to garbage collect incompletely instantiated keys. (CVE-2015-7872) It was discovered that the virtual video osd test driver in the Linux kernel did not properly initialize data structures. (CVE-2015-7884) It was discovered that the driver for Digi Neo and ClassicBoard devices did not properly initialize data structures. (CVE-2015-7885) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 15.10: linux-image-4.2.0-21-generic 4.2.0-21.25 linux-image-4.2.0-21-generic-lpae 4.2.0-21.25 linux-image-4.2.0-21-lowlatency 4.2.0-21.25 linux-image-4.2.0-21-powerpc-e500mc 4.2.0-21.25 linux-image-4.2.0-21-powerpc-smp 4.2.0-21.25 linux-image-4.2.0-21-powerpc64-emb 4.2.0-21.25 linux-image-4.2.0-21-powerpc64-smp 4.2.0-21.25 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. If you use linux-restricted-modules, you have to update that package as well to get modules which work with the new kernel version. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-server, linux-powerpc), a standard system upgrade will automatically perform this as well

AFFECTED PRODUCTS