Astra Linux – Vulnerability in Linux

A vulnerability was discovered in the Linux kernel before version 5.9. Arch/x86/kvm/svm/sev.c allows attackers to cause a denial of service soft lockup by triggering the destruction of a large SEV VM, which requires unregistering many encrypted regions. This vulnerability is also known as...

Astra Linux – Vulnerability in Linux

A flaw was discovered in the KVM’s AMD code, responsible for supporting SVM nested virtualization. The flaw occurs during the processing of the VMCB virtual machine control block provided by the L1 guest, which is used to spawn or handle a nested guest L2. Due to improper validation of the “intct...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1

In the Linux kernel, the following vulnerabilities have been resolved: KVM: x86/pmu: Disabled support for adaptive PEBS. Support for virtualizing adaptive PEBS has been discontinued. This is because KVM’s implementation is architecturally broken without an obvious or easy way to address this issu...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1, and Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM – Flushing pages under kvm-lock to fix a Use-After-Free error in svmregisterencregion It is necessary to flush the cached pages in svmregisterencregion before releasing kvm-lock to address use-after-free issues. In such...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1, Linux, Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: KVM: Always flush the async PF workqueue when a vCPU is being destroyed. Whenever a vCPU clears its completion queue, i.e., when a VM and all its vCPUs are being destroyed, the async PF workqueue must always be flushed. KVM must...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Check instead of asserting on nested TSC scaling support Check for nested TSC scaling support on nested SVM VMRUN instead of asserting that TSC scaling is exposed to L1 if L1’s MSRAMD64TSCRATIO has diverged from KVM’s...

Astra Linux – Vulnerability in Linux, Linux 5.10

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Immediately reset the MMU context when the SMM flag is cleared The MMU context must be reset immediately when the SMM flag of the vCPU is cleared, so that the SMM flag in the MMU context is always synchronized with the...

Astra Linux – Vulnerability in Linux

A issue was discovered in Linux: improper handling of VMIO|VMPFNMAP vmas in KVM can bypass RO checks and may cause pages to be freed while still accessible by the VMM and guest. This allows users who have the ability to start and control a VM to read/write random pages of memory, potentially...

Astra Linux – Vulnerability in Linux 5.10, Linux

A flaw was discovered in KVM. When updating a guest’s page table entry, vmpgoff was incorrectly used as the offset to obtain the page’s pfn. Since vaddr and vmpgoff are controllable by user-mode processes, this flaw allows unprivileged local users on the host to write outside the userspace region...

Astra Linux – Vulnerability in Linux, Linux 5.10

Rogue backends can cause Denial of Service DoS attacks on guests through high-frequency events. This CNA information record relates to multiple Common Vulnerabilities and Exposures CVEs; the text explains which aspects/vulnerabilities correspond to which CVEs. Xen allows for the execution of PV...

Astra Linux – Vulnerability in Qemu

A use-after-free vulnerability was discovered in the virtio-net device of QEMU. This vulnerability can occur when the address of the descriptor belongs to the non-direct access region, due to the numbuffers being set after the virtqueue elem has been unmapped. A malicious guest can exploit this...

Astra Linux – Vulnerability in Linux 5.10

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: smm: the number of GPRs in the SMRAM image depends on the image format. On 64-bit hosts, if the guest does not have X86FEATURELM, KVM will access 16 GPRs to the 32-bit SMMR image, resulting in an out-of-bound RAM access...

Astra Linux – Vulnerability in Linux 5.10

In the Linux kernel, the following vulnerability has been resolved: x86/sev: Use TSCFACTOR for calculating the Secure TSC frequency. When using Secure TSC, the GUESTTSCFREQ MSR reports a frequency based on the nominal P0 frequency, which deviates slightly typically 0.2% from the actual mean TSC...

Astra Linux – Vulnerability in Linux 5.10

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Correctly handling the kvmarminit failure in finalizepkvm Currently, there is no synchronization between the finalizepkvm and kvmarminit initcalls. The finalizepkvm continues to execute even if kvmarminit fails,...

Astra Linux – Vulnerability in Linux 5.10

A flaw was discovered in the Linux kernel. The existing KVM SEV API contains a vulnerability that allows a non-root host user-level application to crash the host kernel by creating a confidential guest VM instance in an AMD CPU that supports Secure Encrypted Virtualization SEV...

Astra Linux – Vulnerability in Linux 5.10

In the Linux kernel, the following vulnerabilities have been resolved: scsi: qedf: Add stagwork to all the vports A call trace was observed when creating NPIV ports. Only 32 out of 64 ports are shown as online. The stagwork was not initialized for the vports; therefore, it needs to be initialized...

Astra Linux – Vulnerability in Linux 5.10

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fixed the host’s stage-2 PGD refcount issue The KVM page-table library counts the pages of concatenated stage-2 PGs individually. However, when KVM runs in protected mode, the host’s stage-2 PGD is currently managed b...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1, and Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: KVM: x86 – Mark the target gfn of the emulated atomic instruction as dirty When emulating an atomic access on behalf of the guest, mark the target gfn as dirty if the CMPXCHG instruction attempts to be executed and fails without ...

Astra Linux – Vulnerabilities in Linux 5.10, Linux 5.15, Linux 6.1

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: pv: fix index value of replaced ASCE The index field of the struct page corresponding to a guest ASCE should be 0. When replacing the ASCE in s390replaceasce, the index of the new ASCE should also be set to 0. Using th...

Astra Linux – Vulnerability in Qemu

A flaw was discovered in the implementation of the 9p passthrough filesystem 9pfs in QEMU. The 9pfs server did not prevent the opening of special files on the host side, potentially allowing a malicious client to escape from the exported 9p tree by creating and opening a device file in the shared...