CVE-2020-29369

CVE-2020-29369 is a real Linux kernel vulnerability described in the connected docs. It is a race condition in mm/mmap.c (expand_downwards vs. expand_upwards) that can occur during munmap page-table free operations, present in Linux kernels before 5.7.11 (CID-246c320a8cfe). The issue is triggered...

CVE-2020-29369

An issue was discovered in mm/mmap.c in the Linux kernel before 5.7.11. There is a race condition between certain expand functions expanddownwards and expandupwards and page-table free operations from an munmap call, aka CID-246c320a8cfe...

Fedora 31 : xen (2020-6dd36a716c)

revised patch for XSA-286 mitigating performance impact ---- x86 PV guest INVLPG-like flushes may leave stale TLB entries XSA-286, CVE-2020-27674 1891092 ---- x86: Race condition in Xen mapping code XSA-345 undue deferral of IOMMU TLB flushes XSA-346 unsafe AMD IOMMU page table updates XSA-347 No...

In the Linux kernel 4.19 through 5.6.7 on the s390 platform code execution may occur because of a race condition as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade aka CID-3f777e19d171. A crash could also occur.

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openSUSE Security Update : xen (openSUSE-2020-1844)

This update for xen fixes the following issues : - bsc1177409 - VUL-0: CVE-2020-27673: xen: x86 PV guest INVLPG-like flushes may leave stale TLB entries XSA-286 - bsc1177412 - VUL-0: CVE-2020-27672: xen: Race condition in Xen mapping code XSA-345 - bsc1177413 - VUL-0: CVE-2020-27671: xen: undue...

CVE-2020-27670

A flaw was found in Xen in the AMD IOMMU page table updates. This flaw allows a malicious guest to cause a denial of service, host data corruption, or potential privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability...

CVE-2020-27670

An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a denial of service data corruption, cause a data leak, or possibly gain privileges because an AMD IOMMU page-table entry can be half-updated...

Linux expand_downwards() / munmap() Race Condition

Linux =4.20: expanddownwards can race with munmap page table freeing Since 4.20, domunmap downgrades the mmapsem from write-locked to read-locked after detaching the VMAs from the mmstruct, but before dropping references to pages and freeing page tables. This ought to be safe because VMA tree...

JITSploitation III: Subverting Control Flow

Posted by Samuel Groß, Project Zero This three-part series highlights the technical challenges involved in finding and exploiting JavaScript engine vulnerabilities in modern web browsers and evaluates current exploit mitigation technologies. The exploited vulnerability, CVE-2020-9802, was fixed i...

CVE-2020-15565

A flaw was found in Xen, in the page table sharing between the IOMMU and CPU. This flaw allows a malicious guest user to access sensitive information pertaining to other guests to crash the host, resulting in a denial of service and privilege escalation. The highest threat from this vulnerability...

CVE-2020-15565

An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both...

DEBIAN-CVE-2020-15565

An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both...

DEBIAN-CVE-2020-15567

An issue was discovered in Xen through 4.13.x, allowing Intel guest OS users to gain privileges or cause a denial of service because of non-atomic modification of a live EPT PTE. When mapping guest EPT nested paging tables, Xen would in some circumstances use a series of non-atomic bitfield write...

CVE-2020-15565

An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both...

Design/Logic Flaw

An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both...

CVE-2020-15565

Root cause: CVE-2020-15565 arises from insufficient cache write-back under VT-d when page tables are shared between IOMMU and CPU, requiring flushing of both CPU and IOMMU TLBs. A backport/backing fixes missed a necessary cache flush, leaving IOMMU updates potentially non-coherent. Affected produ...

CVE-2020-15565

An issue was discovered in Xen through 4.13.x, allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both...

insufficient cache write-back under VT-d

ISSUE DESCRIPTION When page tables are shared between IOMMU and CPU, changes to them require flushing of both TLBs. Furthermore, IOMMUs may be non-coherent, and hence prior to flushing IOMMU TLBs CPU cached also needs writing back to memory after changes were made. Such writing back of cached dat...

Kernel: s390: page table upgrade in secondary address mode may lead to privilege escalation

A flaw was found in the Linux kernel on s390 architecture. The issue occurs on multiprocessing systems when one s390 CPU is in Secondary Address Mode and another CPU does a kernel page table upgrade. An inter-processor interrupt IPI is then sent to each active CPU to update the control registers...

Kernel: s390: page table upgrade in secondary address mode may lead to privilege escalation

A flaw was found in the Linux kernel on s390 architecture. The issue occurs on multiprocessing systems when one s390 CPU is in Secondary Address Mode and another CPU does a kernel page table upgrade. An inter-processor interrupt IPI is then sent to each active CPU to update the control registers...