Описание
Security update for xen
This update for xen fixes the following issues:
Security issues fixed:
- CVE-2018-3665: Fix Lazy FP Save/Restore issue (XSA-267) (bsc#1095242).
- CVE-2018-12891: Fix possible Denial of Service (DoS) via certain PV MMU operations that affect the entire host (XSA-264) (bsc#1097521).
- CVE-2018-12892: Fix libxl to honour the readonly flag on HVM emulated SCSI disks (XSA-266) (bsc#1097523).
- CVE-2018-12893: Fix crash/Denial of Service (DoS) via safety check (XSA-265) (bsc#1097522).
Bug fixes:
- bsc#1027519: Add upstream patches from January.
- bsc#1098403: Fix regression introduced by changes for bsc#1079730. A PV domU without qcow2 and/or vfb has no qemu attached. Ignore QMP errors for PV domUs to handle PV domUs with and without an attached qemu-xen.
- bsc#1087289: Fix xen scheduler crash.
Список пакетов
SUSE Linux Enterprise Module for Basesystem 15
SUSE Linux Enterprise Module for Server Applications 15
Ссылки
- Link for SUSE-SU-2018:1981-1
- E-Mail link for SUSE-SU-2018:1981-1
- SUSE Security Ratings
- SUSE Bug 1027519
- SUSE Bug 1079730
- SUSE Bug 1087289
- SUSE Bug 1095242
- SUSE Bug 1097521
- SUSE Bug 1097522
- SUSE Bug 1097523
- SUSE Bug 1098403
- SUSE CVE CVE-2018-12891 page
- SUSE CVE CVE-2018-12892 page
- SUSE CVE CVE-2018-12893 page
- SUSE CVE CVE-2018-3665 page
Описание
An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions through its own page table contents, a malicious guest may cause such bypasses to be used for an unbounded number of iterations. A malicious or buggy PV guest may cause a Denial of Service (DoS) affecting the entire host. Specifically, it may prevent use of a physical CPU for an indeterminate period of time. All Xen versions from 3.4 onwards are vulnerable. Xen versions 3.3 and earlier are vulnerable to an even wider class of attacks, due to them lacking preemption checks altogether in the affected code paths. Only x86 systems are affected. ARM systems are not affected. Only multi-vCPU x86 PV guests can leverage the vulnerability. x86 HVM or PVH guests as well as x86 single-vCPU PV ones cannot leverage the vulnerability.
Затронутые продукты
Ссылки
- CVE-2018-12891
- SUSE Bug 1097521
- SUSE Bug 1178658
Описание
An issue was discovered in Xen 4.7 through 4.10.x. libxl fails to pass the readonly flag to qemu when setting up a SCSI disk, due to what was probably an erroneous merge conflict resolution. Malicious guest administrators or (in some situations) users may be able to write to supposedly read-only disk images. Only emulated SCSI disks (specified as "sd" in the libxl disk configuration, or an equivalent) are affected. IDE disks ("hd") are not affected (because attempts to make them readonly are rejected). Additionally, CDROM devices (that is, devices specified to be presented to the guest as CDROMs, regardless of the nature of the backing storage on the host) are not affected; they are always read only. Only systems using qemu-xen (rather than qemu-xen-traditional) as the device model version are vulnerable. Only systems using libxl or libxl-based toolstacks are vulnerable. (This includes xl, and libvirt with the libxl driver.) The vulnerability is present in Xen versions 4.7 and later. (In earlier versions, provided that the patch for XSA-142 has been applied, attempts to create read only disks are rejected.) If the host and guest together usually support PVHVM, the issue is exploitable only if the malicious guest administrator has control of the guest kernel or guest kernel command line.
Затронутые продукты
Ссылки
- CVE-2018-12892
- SUSE Bug 1097523
Описание
An issue was discovered in Xen through 4.10.x. One of the fixes in XSA-260 added some safety checks to help prevent Xen livelocking with debug exceptions. Unfortunately, due to an oversight, at least one of these safety checks can be triggered by a guest. A malicious PV guest can crash Xen, leading to a Denial of Service. All Xen systems which have applied the XSA-260 fix are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only x86 PV guests can exploit the vulnerability. x86 HVM and PVH guests cannot exploit the vulnerability. An attacker needs to be able to control hardware debugging facilities to exploit the vulnerability, but such permissions are typically available to unprivileged users.
Затронутые продукты
Ссылки
- CVE-2018-12893
- SUSE Bug 1097522
- SUSE Bug 1178658
Описание
System software utilizing Lazy FP state restore technique on systems using Intel Core-based microprocessors may potentially allow a local process to infer data from another process through a speculative execution side channel.
Затронутые продукты
Ссылки
- CVE-2018-3665
- SUSE Bug 1087078
- SUSE Bug 1087082
- SUSE Bug 1087086
- SUSE Bug 1090338
- SUSE Bug 1095241
- SUSE Bug 1095242
- SUSE Bug 1096740
- SUSE Bug 1100091
- SUSE Bug 1100555
- SUSE Bug 1178658