CVE-2020-12888: Medium severity IBM Data Risk Manager vulnerability
A flaw was found in the Linux kernel, where it allows userspace processes, for example, a guest VM, to directly access h/w devices via its VFIO driver modules. The VFIO modules allow users to enable or disable access to the devices' MMIO memory address spaces. If a user attempts to access the read/write devices' MMIO address space when it is disabled, some h/w devices issue an interrupt to the CPU to indicate a fatal error condition, crashing the system. This flaw allows a guest user or process to crash the host system resulting in a denial of service.
Other sources
Linux kernel allows user space processes (like guest VM) to directly access h/w devices via its VFIO driver modules. The VFIO modules allow users to enable or disable access to the devices' MMIO memory address spaces. If a user attempts to access(r/w) devices' MMIO address space, when it is disabled, some h/w devices issue an interrupt to the CPU to indicate a fatal error condition, essentially crashing down the system. A guest user/process may use this flaw to crash the host system resulting in DoS scenario.
Upstream patches: ----------------- -> https://lore.kernel.org/kvm/158871570274.15589.10563806532874116326.stgit@gimli.home/ -> https://lore.kernel.org/kvm/158871401328.15589.17598154478222071285.stgit@gimli.home/
Reference: ---------- -> https://www.openwall.com/lists/oss-security/2020/05/19/6
— Red Hat
Linux Kernel is vulnerable to a denial of service, caused by improper handling of attempts to access disabled memory space by the VFIO PCI driver. By sending a specially-crafted request, a local attacker could exploit this vulnerability to cause a denial of service condition.
— IBM
The VFIO PCI driver in the Linux kernel through 5.6.13 mishandles attempts to access disabled memory space.
Affected Software
Remediation
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2020-12888?
CVE-2020-12888 is categorized as a high-severity vulnerability affecting the Linux kernel.
How do I fix CVE-2020-12888?
To fix CVE-2020-12888, update your Linux kernel to the patched version provided by your distribution.
What products are affected by CVE-2020-12888?
CVE-2020-12888 affects multiple distributions of the Linux kernel, including specific versions from RedHat, Debian, Ubuntu, and Fedora.
What types of attacks can exploit CVE-2020-12888?
CVE-2020-12888 can be exploited by malicious userspace processes to gain unauthorized access to hardware devices.
When was CVE-2020-12888 disclosed?
CVE-2020-12888 was disclosed in July 2020.