CVE-2020-11743

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

This update for xen fixes the following issues:

Security issues fixed:

• CVE-2020-11742: Bad continuation handling in GNTTABOP_copy (bsc#1169392).
• CVE-2020-11740, CVE-2020-11741: xen: XSA-313 multiple xenoprof issues (bsc#1168140).
• CVE-2020-11739: Missing memory barriers in read-write unlock paths (bsc#1168142).
• CVE-2020-11743: Bad error path in GNTTABOP_map_grant (bsc#1168143).
• arm: a CPU may speculate past the ERET instruction (bsc#1160932).

Non-security issues fixed:

• Xenstored Crashed during VM install (bsc#1167152)
• DomU hang: soft lockup CPU #0 stuck under high load (bsc#1165206, bsc#1134506)
• Update API compatibility versions, fixes issues for libvirt. (bsc#1167007, bsc#1157490)
• aacraid blocks xen commands (bsc#1155200)

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

Security issues fixed:

• CVE-2020-11742: Bad continuation handling in GNTTABOP_copy (bsc#1169392).
• CVE-2020-11740, CVE-2020-11741: xen: XSA-313 multiple xenoprof issues (bsc#1168140).
• CVE-2020-11739: Missing memory barriers in read-write unlock paths (bsc#1168142).
• CVE-2020-11743: Bad error path in GNTTABOP_map_grant (bsc#1168143).
• arm: a CPU may speculate past the ERET instruction (bsc#1160932).

Non-security issues fixed:

• Xenstored Crashed during VM install (bsc#1167152)
• DomU hang: soft lockup CPU #0 stuck under high load (bsc#1165206, bsc#1134506)
• Update API compatibility versions, fixes issues for libvirt. (bsc#1167007, bsc#1157490)
• aacraid blocks xen commands (bsc#1155200)

This update for xen fixes the following issues:

Security issues fixed:

• CVE-2020-11742: Bad continuation handling in GNTTABOP_copy (bsc#1169392).
• CVE-2020-11740, CVE-2020-11741: xen: XSA-313 multiple xenoprof issues (bsc#1168140).
• CVE-2020-11739: Missing memory barriers in read-write unlock paths (bsc#1168142).
• CVE-2020-11743: Bad error path in GNTTABOP_map_grant (bsc#1168143).
• CVE-2020-7211: Fixed potential directory traversal using relative paths via tftp server on Windows host (bsc#1161181).
• arm: a CPU may speculate past the ERET instruction (bsc#1160932).

Non-security issues fixed:

• Xenstored Crashed during VM install (bsc#1167152)
• DomU hang: soft lockup CPU #0 stuck under high load (bsc#1165206, bsc#1134506)
• Update API compatibility versions, fixes issues for libvirt. (bsc#1167007, bsc#1157490)
• aacraid blocks xen commands (bsc#1155200)

This update for xen to version 4.12.2 fixes the following issues:

Security issues fixed:

• CVE-2020-11742: Bad continuation handling in GNTTABOP_copy (bsc#1169392).
• CVE-2020-11740, CVE-2020-11741: xen: XSA-313 multiple xenoprof issues (bsc#1168140).
• CVE-2020-11739: Missing memory barriers in read-write unlock paths (bsc#1168142).
• CVE-2020-11743: Bad error path in GNTTABOP_map_grant (bsc#1168143).
• CVE-2020-7211: Fixed potential directory traversal using relative paths via tftp server on Windows host (bsc#1161181).
• arm: a CPU may speculate past the ERET instruction (bsc#1160932).

Non-security issues fixed:

• Xenstored Crashed during VM install (bsc#1167152)
• DomU hang: soft lockup CPU #0 stuck under high load (bsc#1165206, bsc#1134506)
• Update API compatibility versions, fixes issues for libvirt. (bsc#1167007, bsc#1157490)
• aacraid blocks xen commands (bsc#1155200)
• Problems Booting Fedora31 VM on sles15 sp1 Xen Dom0 (bsc#1162040).

This update for xen fixes the following issues:

• CVE-2020-0543: Fixed a side channel attack against special registers which could have resulted in leaking of read values to cores other than the one which called it. This attack is known as Special Register Buffer Data Sampling (SRBDS) or 'CrossTalk' (bsc#1172205).
• CVE-2020-11742: Bad continuation handling in GNTTABOP_copy (bsc#1169392).
• CVE-2020-11740, CVE-2020-11741: xen: XSA-313 multiple xenoprof issues (bsc#1168140).
• CVE-2020-11739: Missing memory barriers in read-write unlock paths (bsc#1168142).
• CVE-2020-11743: Bad error path in GNTTABOP_map_grant (bsc#1168143).
• Xenstored Crashed during VM install (bsc#1167152)

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)