A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result the L2 guest would be allowed to read/write physical pages of the host resulting in a crash of the entire system leak of sensitive data or potential guest-to-host escape. This flaw affects Linux kernel versions prior to 5.14-rc7.

🗓️ 09 Oct 2021 07:00:00Reported by MicrosoftType

KVM AMD SVM nested flaw: invalid int_ctl enables AVIC for L2, risking host memory access.

Reporter	Title	Published	Views	Family All 509
IBM Security Bulletins	Security Bulletin: Multiple vulnerabilities in Linux Kernel affect IBM QRadar SIEM (CVE-2021-22543, CVE-2021-3653, CVE-2021-3656, CVE-2021-37576)	28 Apr 202220:56	–	ibm
Tenable Nessus	Amazon Linux 2 : kernel (ALAS-2021-1704)	16 Sep 202100:00	–	nessus
Tenable Nessus	Amazon Linux 2 : kernel (ALASKERNEL-5.10-2022-005)	2 May 202200:00	–	nessus
Tenable Nessus	Amazon Linux 2 : microvm-kernel (ALASMICROVM-KERNEL-4.14-2023-002)	27 Sep 202300:00	–	nessus
Tenable Nessus	Amazon Linux 2 : microvm-kernel (ALASMICROVM-KERNEL-4.14-2023-003)	27 Sep 202300:00	–	nessus
Tenable Nessus	AlmaLinux 8 : kernel (ALSA-2021:3548)	9 Feb 202200:00	–	nessus
Tenable Nessus	CentOS 8 : kernel (CESA-2021:3548)	15 Sep 202100:00	–	nessus
Tenable Nessus	CentOS 7 : kernel (RHSA-2021:3801)	17 Nov 202100:00	–	nessus
Tenable Nessus	Debian DLA-2843-1 : linux - LTS security update	17 Dec 202100:00	–	nessus
Tenable Nessus	Debian DSA-4978-1 : linux - security update	25 Sep 202100:00	–	nessus