CVE-2018-7540

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing.

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing.

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 several issues.

These security issues were fixed:

• CVE-2017-5753, CVE-2017-5715, CVE-2017-5754: Prevent information leaks via side effects of speculative execution, aka 'Spectre' and 'Meltdown' attacks (bsc#1074562, bsc#1068032)
• CVE-2018-5683: The vga_draw_text function allowed local OS guest privileged users to cause a denial of service (out-of-bounds read and QEMU process crash) by leveraging improper memory address validation (bsc#1076116).
• CVE-2017-18030: The cirrus_invalidate_region function allowed local OS guest privileged users to cause a denial of service (out-of-bounds array access and QEMU process crash) via vectors related to negative pitch (bsc#1076180).
• CVE-2017-15595: x86 PV guest OS users were able to cause a DoS (unbounded recursion, stack consumption, and hypervisor crash) or possibly gain privileges via crafted page-table stacking (bsc#1061081)
• CVE-2017-17566: Prevent PV guest OS users to cause a denial of service (host OS crash) or gain host OS privileges in shadow mode by mapping a certain auxiliary page (bsc#1070158).
• CVE-2017-17563: Prevent guest OS users to cause a denial of service (host OS crash) or gain host OS privileges by leveraging an incorrect mask for reference-count overflow checking in shadow mode (bsc#1070159).
• CVE-2017-17564: Prevent guest OS users to cause a denial of service (host OS crash) or gain host OS privileges by leveraging incorrect error handling for reference counting in shadow mode (bsc#1070160).
• CVE-2017-17565: Prevent PV guest OS users to cause a denial of service (host OS crash) if shadow mode and log-dirty mode are in place, because of an incorrect assertion related to M2P (bsc#1070163).
• Added missing intermediate preemption checks for guest requesting removal of memory. This allowed malicious guest administrator to cause denial of service due to the high cost of this operation (bsc#1080635).
• Because of XEN not returning the proper error messages when transitioning grant tables from v2 to v1 a malicious guest was able to cause DoS or potentially allowed for privilege escalation as well as information leaks (bsc#1080662).
• CVE-2017-5898: The CCID Card device emulator support was vulnerable to an integer overflow flaw allowing a privileged user to crash the Qemu process on the host resulting in DoS (bsc#1024307)
• Unprivileged domains could have issued well-timed writes to xenstore which conflict with transactions to stall progress of the control domain or driver domain, possibly leading to DoS (bsc#1030144, XSA-206).

This update for xen fixes the following issues:

Update to Xen 4.7.5 bug fix only release (bsc#1027519)

Security issues fixed:

• CVE-2018-7540: Fixed DoS via non-preemptable L3/L4 pagetable freeing (XSA-252) (bsc#1080635)

• CVE-2018-7541: A grant table v2 -> v1 transition may crash Xen (XSA-255) (bsc#1080662)

• CVE-2017-5753,CVE-2017-5715,CVE-2017-5754 Fixed information leaks via side effects of speculative execution (XSA-254). Includes Spectre v2 mitigation. (bsc#1074562)

• Preserve xen-syms from xen-dbg.gz to allow processing vmcores with crash(1) (bsc#1087251)

• Xen HVM: Fixed unchecked MSR access error (bsc#1072834)

• Add script, udev rule and systemd service to watch for vcpu online/offline events in a HVM domU They are triggered via xl vcpu-set domU N (fate#324965)

• Make sure tools and tools-domU require libs from the very same build

This update for xen to version 4.9.2 fixes several issues.

This feature was added:

• Added script, udev rule and systemd service to watch for vcpu online/offline events in a HVM domU. They are triggered via 'xl vcpu-set domU N'

These security issues were fixed:

• CVE-2018-8897: Prevent mishandling of debug exceptions on x86 (XSA-260, bsc#1090820)
• Handle HPET timers in IO-APIC mode correctly to prevent malicious or buggy HVM guests from causing a hypervisor crash or potentially privilege escalation/information leaks (XSA-261, bsc#1090822)
• Prevent unbounded loop, induced by qemu allowing an attacker to permanently keep a physical CPU core busy (XSA-262, bsc#1090823)
• CVE-2018-10472: x86 HVM guest OS users (in certain configurations) were able to read arbitrary dom0 files via QMP live insertion of a CDROM, in conjunction with specifying the target file as the backing file of a snapshot (bsc#1089152).
• CVE-2018-10471: x86 PV guest OS users were able to cause a denial of service (out-of-bounds zero write and hypervisor crash) via unexpected INT 80 processing, because of an incorrect fix for CVE-2017-5754 (bsc#1089635).
• CVE-2018-7540: x86 PV guest OS users were able to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing (bsc#1080635).
• CVE-2018-7541: Guest OS users were able to cause a denial of service (hypervisor crash) or gain privileges by triggering a grant-table transition from v2 to v1 (bsc#1080662).
• CVE-2018-7542: x86 PVH guest OS users were able to cause a denial of service (NULL pointer dereference and hypervisor crash) by leveraging the mishandling of configurations that lack a Local APIC (bsc#1080634).

These non-security issues were fixed:

• bsc#1087252: Update built-in defaults for xenstored in stubdom, keep default to run xenstored as daemon in dom0
• bsc#1087251: Preserve xen-syms from xen-dbg.gz to allow processing vmcores with crash(1)
• bsc#1072834: Prevent unchecked MSR access error