| Descripción: | Summary:
The remote host is missing an update for the 'kernel'
package(s) announced via the referenced advisory.
Vulnerability Insight:
The kernel packages contain the Linux kernel,
the core of any Linux operating system.
* It was found that the x86 ISA (Instruction Set Architecture) is prone to
a denial of service attack inside a virtualized environment in the form of
an infinite loop in the microcode due to the way (sequential) delivering of
benign exceptions such as #AC (alignment check exception) and #DB (debug
exception) is handled. A privileged user inside a guest could use these
flaws to create denial of service conditions on the host kernel.
(CVE-2015-5307, CVE-2015-8104, Important)
Red Hat would like to thank Ben Serebrin of Google Inc. for reporting the
CVE-2015-5307 issue.
This update also fixes the following bugs:
* On Intel Xeon v5 platforms, the processor frequency was always tied to
the highest possible frequency. Switching p-states on these client
platforms failed. This update sets the idle frequency, busy frequency, and
processor frequency values by determining the range and adjusting the
minimal and maximal percent limit values. Now, switching p-states on the
aforementioned client platforms proceeds successfully. (BZ#1273926)
* Due to a validation error of in-kernel memory-mapped I/O (MMIO) tracing,
a VM became previously unresponsive when connected to Red Hat Enterprise
Virtualization Hypervisor. The provided patch fixes this bug by dropping
the check in MMIO handler, and a VM continues running as expected.
(BZ#1275150)
* Due to retry-able command errors, the NVMe driver previously leaked I/O
descriptors and DMA mappings. As a consequence, the kernel could become
unresponsive during the hot-unplug operation if a driver was removed.
This update fixes the driver memory leak bug on command retries, and the
kernel no longer hangs in this situation. (BZ#1279792)
* The hybrid_dma_data() function was not initialized before use, which
caused an invalid memory access when hot-plugging a PCI card. As a
consequence, a kernel oops occurred. The provided patch makes sure
hybrid_dma_data() is initialized before use, and the kernel oops no longer
occurs in this situation. (BZ#1279793)
* When running PowerPC (PPC) KVM guests and the host was experiencing a lot
of page faults, for example because it was running low on memory, the host
sometimes triggered an incorrect kind of interrupt in the guest: a data
storage exception instead of a data segment exception. This caused a kernel
panic of the PPC KVM guest. With this update, the host kernel synthesizes a
segment fault if the corresponding Segment Lookaside Buffer (SLB) lookup
fails, which prevents the kernel panic from occurring. (BZ#1281423 ...
Description truncated, please see the referenced URL(s) for more information.
Affected Software/OS:
kernel on Red Hat Enterprise Linux Server (v. 7)
Solution:
Please Install the Updated Packages.
CVSS Score:
4.9
CVSS Vector:
AV:L/AC:L/Au:N/C:N/I:N/A:C
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