Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2016-3656)

The remote Oracle Linux 6 / 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2016-3656 advisory. - x86/iopl/64: properly context-switch IOPL on Xen PV Andy Lutomirski Orabug: 25269176 CVE-2016-3157 CVE-2016-3157 Tenable has extracted the...

OracleVM 3.2 : Unbreakable / etc (OVMSA-2016-0181)

The remote OracleVM system is missing necessary patches to address critical security updates : - x86/iopl/64: properly context-switch IOPL on Xen PV Andy Lutomirski Orabug: 25269184 CVE-2016-3157 - net: Fix use after free in the recvmmsg exit path Arnaldo Carvalho de Melo Orabug: 25298618...

FreeBSD : xen-kernel -- x86 PV guests may be able to mask interrupts (3ae078ca-c7eb-11e6-ae1b-002590263bf5)

The Xen Project reports : Certain PV guest kernel operations page table writes in particular need emulation, and use Xen's general x86 instruction emulator. This allows a malicious guest kernel which asynchronously modifies its instruction stream to effect the clearing of EFLAGS.IF from the state...

x86 PV guests may be able to mask interrupts

ISSUE DESCRIPTION Certain PV guest kernel operations page table writes in particular need emulation, and use Xen's general x86 instruction emulator. This allows a malicious guest kernel which asynchronously modifies its instruction stream to effect the clearing of EFLAGS.IF from the state used to...

xen-kernel -- x86 PV guests may be able to mask interrupts

The Xen Project reports: Certain PV guest kernel operations page table writes in particular need emulation, and use Xen's general x86 instruction emulator. This allows a malicious guest kernel which asynchronously modifies its instruction stream to effect the clearing of EFLAGS.IF from the state...

x86: Mishandling of SYSCALL singlestep during emulation

ISSUE DESCRIPTION The typical behaviour of singlestepping exceptions is determined at the start of the instruction, with a DB trap being raised at the end of the instruction. SYSCALL and SYSRET, although we don't implement it behave differently because the typical behaviour allows userspace to...

qemu ioport array overflow

ISSUE DESCRIPTION The code in qemu which implements ioport read/write looks up the specified ioport address in a dispatch table. The argument to the dispatch function is a uint32t, and is used without a range check, even though the table has entries for only 2^16 ioports. When qemu is used as a...

FreeBSD : xen-kernel -- x86: Disallow L3 recursive pagetable for 32-bit PV guests (45ca25b5-ba4d-11e6-ae1b-002590263bf5)

The Xen Project reports : On real hardware, a 32-bit PAE guest must leave the USER and RW bit clear in L3 pagetable entries, but the pagetable walk behaves as if they were set. The L3 entries are cached in processor registers, and don't actually form part of the pagewalk. When running a 32-bit PV...

x86 segment base write emulation lacking canonical address checks

ISSUE DESCRIPTION Both writes to the FS and GS register base MSRs as well as the WRFSBASE and WRGSBASE instructions require their input values to be canonical, or a GP fault will be raised. When the use of those instructions by the hypervisor was enabled, the previous guard against GP faults havi...

Fedora 25 : xen (2016-1d8429b89f)

fix build problem with glibc 2.24 x86: Disallow L3 recursive pagetable for 32-bit PV guests XSA-185, CVE-2016-7092 x86: Mishandling of instruction pointer truncation during emulation XSA-186, CVE-2016-7093 x86 HVM: Overflow of shctxt-segreg XSA-187, CVE-2016-7094 pandoc documentation has dependen...

util-linux security, bug fix, and enhancement update

2.23.2-33.0.1 - fix Oracle bug 23001516 - backport lscpu: correct the Virtualization type on Xen DomU PV guest - Reviewed-by: Joe Jin 2.23.2-33 - improve patch for 1007734 libblkid realpaths 2.23.2-32 - improve patch for chrt1 deadline support 1298384 - fix 1007734 - blkid shows devices as...

Upgrading to Ubuntu 14.04, RHEL 7 and CentOS 7 Guests

Customers who wish to upgrade existing Linux guests to versions which now operate in HVM mode that is, RHEL7, CentOS 7, and Ubuntu 14.04 should perform an in-guest upgrade. At this point, the upgraded Guest will only run in PV mode - which is not supported and has known issues. Customers should r...

Fedora 23 : xen (2016-1c3374bcb9)

x86: Disallow L3 recursive pagetable for 32-bit PV guests XSA-185, CVE-2016-7092 1374470 x86: Mishandling of instruction pointer truncation during emulation XSA-186, CVE-2016-7093 1374471 x86 HVM: Overflow of shctxt-segreg XSA-187, CVE-2016-7094 1374473 Note that Tenable Network Security has...

CVE-2016-7092

The getpagefroml3e function in arch/x86/mm.c in Xen allows local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables...

Design/Logic Flaw

The getpagefroml3e function in arch/x86/mm.c in Xen allows local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables...

CVE-2016-7092

The getpagefroml3e function in arch/x86/mm.c in Xen allows local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables...

CVE-2016-7092

CVE-2016-7092 affects Xen: the get_page_from_l3e function in arch/x86/mm.c allows a local 32-bit PV guest administrator to gain host OS privileges via vectors related to L3 recursive pagetables. Connected advisories reference upstream XSA-185 and related fixes, indicating this is a privilege-esca...

Fedora 24 : xen (2016-7d2c67d1f5)

x86: Disallow L3 recursive pagetable for 32-bit PV guests XSA-185, CVE-2016-7092 1374470 x86: Mishandling of instruction pointer truncation during emulation XSA-186, CVE-2016-7093 1374471 x86 HVM: Overflow of shctxt-segreg XSA-187, CVE-2016-7094 1374473 Note that Tenable Network Security has...

Xen release 4 an important vulnerability advisories-vulnerability warning-the black bar safety net

! Today the Xen Update 4 important patch announcement XSA-1 8 5, AND XSA-1 8 6, AND XSA-1 8 7, AND XSA-1 8 8, wherein the XSA-1 8 5, AND XSA-1 8 6, AND XSA-1 8 8 can be caused to include PV, HVM mode in Xen host is penetrated, the recommended use of the Xen Platform Update Now patch. XSA-1 8 5CVE...

x86: Disallow L3 recursive pagetable for 32-bit PV guests

ISSUE DESCRIPTION On real hardware, a 32-bit PAE guest must leave the USER and RW bit clear in L3 pagetable entries, but the pagetable walk behaves as if they were set. The L3 entries are cached in processor registers, and don't actually form part of the pagewalk. When running a 32-bit PV guest o...