Xen - Pagetable De-typing Unbounded Recursion

Xen allows pagetables of the same level to map each other as readonly in PV domains. This is useful if a guest wants to use the self-referential pagetable trick for easy access to pagetables by mapped virtual address. When cleaning up a pagetable after the last typed reference to it has been...

Xen - Unbounded Recursion in Pagetable De-typing Vulnerability

Exploit for linux platform in category dos / poc Xen allows pagetables of the same level to map each other as readonly in PV domains. This is useful if a guest wants to use the self-referential pagetable trick for easy access to pagetables by mapped virtual address. When cleaning up a pagetable...

x86: Incorrect handling of self-linear shadow mappings with translated guests

ISSUE DESCRIPTION The shadow pagetable code uses linear mappings to inspect and modify the shadow pagetables. A linear mapping which points back to itself is known as self-linear. For translated guests, the shadow linear mappings being in a separate address space are not intended to be self-linea...

page type reference leak on x86

ISSUE DESCRIPTION The page type system of Xen requires cleanup when the last reference for a given page is being dropped. In order to exclude simultaneous updates to a given page by multiple parties, pages which are updated are locked beforehand. This locking includes temporarily increasing the...

x86: Incorrect handling of IST settings during CPU hotplug

ISSUE DESCRIPTION The x86-64 architecture allows interrupts to be run on distinct stacks. The choice of stack is encoded in a field of the corresponding interrupt descriptor in the Interrupt Descriptor Table IDT. That field selects an entry from the active Task State Segment TSS. Since, on AMD...

Unlimited recursion in linear pagetable de-typing

ISSUE DESCRIPTION x86 PV guests are permitted to set up certain forms of what is often called "linear page tables", where pagetables contain references to other pagetables at the same level or higher. Certain restrictions apply in order to fit into Xen's page type handling system. An important...

[SECURITY] [DSA 3981-1] linux security update

------------------------------------------------------------------------- Debian Security Advisory DSA-3981-1 [email protected] https://www.debian.org/security/ Salvatore Bonaccorso September 20, 2017 https://www.debian.org/security/faq -...

Security update for xen (important)

This update for xen fixes several issues. These security issues were fixed: - CVE-2017-14316: Missing bound check in function allocheappages for an internal array allowed attackers using crafted hypercalls to execute arbitrary code within Xen XSA-231, bsc1056278 - CVE-2017-14318: The function...

Missing NUMA node parameter verification

ISSUE DESCRIPTION The function allocheappages allows callers to specify the first NUMA node that should be used for allocations through the memflags parameter; the node is extracted using the MEMFgetnode macro. While the function checks to see if the special constant NUMANONODE is specified, it...

Missing check for grant table

ISSUE DESCRIPTION The function gnttabcacheflush handles GNTTABOPcacheflush grant table operations. It checks to see if the calling domain is the owner of the page that is to be operated on. If it is not, the owner's grant table is checked to see if a grant mapping to the calling domain exists for...

cxenstored: Race in domain cleanup

ISSUE DESCRIPTION When shutting down a VM with a stubdomain, a race in cxenstored may cause a double-free. IMPACT The xenstored daemon may crash, resulting in a DoS of any parts of the system relying on it including domain creation / destruction, ballooning, device changes, etc. VULNERABLE SYSTEM...

insufficient grant unmapping checks for x86 PV guests

ISSUE DESCRIPTION When removing or replacing a grant mapping, the x86 PV specific path needs to make sure page table entries remain in sync with other accounting done. Although the identity of the page frame was validated correctly, neither the presence of the mapping nor page writability were...

OracleVM 3.2 : xen (OVMSA-2017-0149)

The remote OracleVM system is missing necessary patches to address critical security updates : - From e26560a4b056dad6d85ffd9ebfad9565f210a9cc Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 30 May 2012 09:22:17 +0100 Subject: PATCH gnttab: don't use domain lock for serialization Instead us...

CVE-2017-12137

arch/x86/mm.c in Xen allows local PV guest OS users to gain host OS privileges via vectors related to mapgrantref...

CVE-2017-12137

arch/x86/mm.c in Xen allows local PV guest OS users to gain host OS privileges via vectors related to mapgrantref...

CVE-2017-12137

arch/x86/mm.c in Xen allows local PV guest OS users to gain host OS privileges via vectors related to mapgrantref...

x86: PV privilege escalation via map_grant_ref

ISSUE DESCRIPTION When mapping a grant reference, a guest must inform Xen of where it would like the grant mapped. For PV guests, this is done by nominating an existing linear address, or an L1 pagetable entry, to be altered. Neither of these PV paths check for alignment of the passed parameter...

Wheat Home Edition Android App Has Override Access Vulnerability

Wheat Home Edition app is a video surveillance software that provides PV monitoring services. Wheat Home Edition Android App suffers from an override access vulnerability. Attackers can utilize the vulnerability to arbitrarily view sensitive information such as user's cell phone number, email...

Arbitrary Account Password Reset Vulnerability in PV Guard Android APP

PV Guard is a PV monitoring and operation management platform based on big data and knowledge base. The PV Guard Android APP has an arbitrary account password reset vulnerability, which allows attackers to exploit the vulnerability to change the password of the other party's cell phone number onl...

Races in the grant table unmap code

ISSUE DESCRIPTION We have discovered two bugs in the code unmapping grant references. When a grant had been mapped twice by a backend domain, and then unmapped by two concurrent unmap calls, the frontend may be informed that the page had no further mappings when the first call completed rather th...