CVE-2020-15563

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HVM guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Xen versions from 4.8 onwards are affected. Xen versions 4.7 and earlier are not affected. Only x86 systems are affected. Arm systems are not affected. Only x86 HVM guests using shadow paging can leverage the vulnerability. In addition, there needs to be an entity actively monitoring a guest's video frame buffer (typically for display purposes) in order for such a guest to be able to leverage the vulnerability. x86 PV guests, as well as x86 HVM guests using hardware assisted paging (HAP), cannot leverage the vulnerability.

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HVM guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Xen versions from 4.8 onwards are affected. Xen versions 4.7 and earlier are not affected. Only x86 systems are affected. Arm systems are not affected. Only x86 HVM guests using shadow paging can leverage the vulnerability. In addition, there needs to be an entity actively monitoring a guest's video frame buffer (typically for display purposes) in order for such a guest to be able to leverage the vulnerability. x86 PV guests, as well as x86 HVM guests using hardware assisted paging (HAP), cannot leverage the vulnerability.

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).
• CVE-2020-0543: Special Register Buffer Data Sampling (SRBDS) aka 'CrossTalk' (bsc#1172205).

Additional upstream bug fixes (bsc#1027519)

This update was imported from the SUSE:SLE-15-SP1:Update update project.

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).
• CVE-2020-0543: Special Register Buffer Data Sampling (SRBDS) aka 'CrossTalk' (bsc#1172205).

Additional upstream bug fixes (bsc#1027519)

This update was imported from the SUSE:SLE-15-SP2:Update update project.

These are all security issues fixed in the xen-4.15.1_01-1.2 package on the GA media of openSUSE Tumbleweed.

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).
• CVE-2020-0543: Special Register Buffer Data Sampling (SRBDS) aka 'CrossTalk' (bsc#1172205).

Additional upstream bug fixes (bsc#1027519)

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).
• CVE-2020-0543: Special Register Buffer Data Sampling (SRBDS) aka 'CrossTalk' (bsc#1172205).

Additional upstream bug fixes (bsc#1027519)

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).

This update for xen fixes the following issues:

• CVE-2020-15563: Fixed inverted code paths in x86 dirty VRAM tracking (bsc#1173377).
• CVE-2020-15565: Fixed insufficient cache write-back under VT-d (bsc#1173378).
• CVE-2020-15566: Fixed incorrect error handling in event channel port allocation (bsc#1173376).
• CVE-2020-15567: Fixed non-atomic modification of live EPT PTE (bsc#1173380).
• CVE-2020-0543: Special Register Buffer Data Sampling (SRBDS) aka 'CrossTalk' (bsc#1172205).

Additional upstream bug fixes (bsc#1027519)

It was discovered that memory contents previously stored in microarchitectural special registers after RDRAND, RDSEED, and SGX EGETKEY read operations on Intel client and Xeon E3 processors may be briefly exposed to processes on the same or different processor cores. A local attacker could use this to expose sensitive information. (CVE-2020-0543)

Julien Grall discovered that Xen incorrectly handled memory barriers on ARM-based systems. An attacker could possibly use this issue to cause a denial of service, obtain sensitive information or escalate privileges. (CVE-2020-11739)

Ilja Van Sprundel discovered that Xen incorrectly handled profiling of guests. An unprivileged attacker could use this issue to obtain sensitive information from other guests, cause a denial of service or possibly gain privileges. (CVE-2020-11740, CVE-2020-11741)

It was discovered that Xen incorrectly handled grant tables. A malicious guest could possibly use this issue to cause a denial of service. (CVE-2020-11742, CVE-2020-11743)

Jan Beulich discovered that Xen incorrectly handled certain code paths. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-15563)

Julien Grall discovered that Xen incorrectly verified memory addresses provided by the guest on ARM-based systems. A malicious guest administrator could possibly use this issue to cause a denial of service. (CVE-2020-15564)

Roger Pau Monné discovered that Xen incorrectly handled caching on x86 Intel systems. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-15565)

It was discovered that Xen incorrectly handled error in event-channel port allocation. A malicious guest could possibly use this issue to cause a denial of service. (CVE-2020-15566)

Jan Beulich discovered that Xen incorrectly handled certain EPT (Extended Page Tables). An attacker could possibly use this issue to cause a denial of service, data corruption or privilege escalation. (CVE-2020-15567)

Andrew Cooper discovered that Xen incorrectly handled PCI passthrough. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25595)

Andrew Cooper discovered that Xen incorrectly sanitized path injections. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25596)

Jan Beulich discovered that Xen incorrectly handled validation of event channels. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25597)

Julien Grall and Jan Beulich discovered that Xen incorrectly handled resetting event channels. An attacker could possibly use this issue to cause a denial of service or obtain sensitive information. (CVE-2020-25599)

Julien Grall discovered that Xen incorrectly handled event channels memory allocation on 32-bits domains. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25600)

Jan Beulich discovered that Xen incorrectly handled resetting or cleaning up event channels. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25601)

Andrew Cooper discovered that Xen incorrectly handled certain Intel specific MSR (Model Specific Registers). An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25602)

Julien Grall discovered that Xen incorrectly handled accessing/allocating event channels. An attacker could possibly use this issue to cause a denial of service, obtain sensitive information of privilege escalation. (CVE-2020-25603)

Igor Druzhinin discovered that Xen incorrectly handled locks. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-25604)