(RHSA-2017:1430) Important: qemu-kvm security and bug fix update

Kernel-based Virtual Machine (KVM) is a full virtualization solution for Linux on a variety of architectures. The qemu-kvm package provides the user-space component for running virtual machines that use KVM.

Security Fix(es):

• An out-of-bounds r/w access issue was found in QEMU’s Cirrus CLGD 54xx VGA Emulator support. The vulnerability could occur while copying VGA data via various bitblt functions. A privileged user inside a guest could use this flaw to crash the QEMU process or, potentially, execute arbitrary code on the host with privileges of the QEMU process. (CVE-2017-7980)

• An out-of-bounds access issue was found in QEMU’s Cirrus CLGD 54xx VGA Emulator support. The vulnerability could occur while copying VGA data using bitblt functions (for example, cirrus_bitblt_rop_fwd_transp_). A privileged user inside a guest could use this flaw to crash the QEMU process, resulting in denial of service. (CVE-2017-7718)

Red Hat would like to thank Jiangxin (PSIRT Huawei Inc) and Li Qiang (Qihoo 360 Gear Team) for reporting CVE-2017-7980 and Jiangxin (PSIRT Huawei Inc) for reporting CVE-2017-7718.

Bug Fix(es):

• Previously, guest virtual machines in some cases became unresponsive when the “pty” back end of a serial device performed an irregular I/O communication. This update improves the handling of serial I/O on guests, which prevents the described problem from occurring. (BZ#1452332)