Debian Security Advisory DSA 4564-1 (linux - security update)

The remote host is missing an update for the 'linux' package(s) announced via the DSA-4564-1 advisory.

Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service, or information leak. CVE-2018-12207 It was discovered that on Intel CPUs supporting hardware virtualisation with Extended Page Tables (EPT), a guest VM may manipulate the memory management hardware to cause a Machine Check Error (MCE) and denial of service (hang or crash). The guest triggers this error by changing page tables without a TLB flush, so that both 4 KB and 2 MB entries for the same virtual address are loaded into the instruction TLB (iTLB). This update implements a mitigation in KVM that prevents guest VMs from loading 2 MB entries into the iTLB. This will reduce performance of guest VMs. A qemu update adding support for the PSCHANGE_MC_NO feature, which allows to disable iTLB Multihit mitigations in nested hypervisors will be provided via DSA 4566-1. CVE-2019-0154 Intel discovered that on their 8th and 9th generation GPUs, reading certain registers while the GPU is in a low-power state can cause a system hang. A local user permitted to use the GPU can use this for denial of service. This update mitigates the issue through changes to the i915 driver. CVE-2019-0155 Intel discovered that their 9th generation and newer GPUs are missing a security check in the Blitter Command Streamer (BCS). A local user permitted to use the GPU could use this to access any memory that the GPU has access to, which could result in a denial of service (memory corruption or crash), a leak of sensitive information, or privilege escalation. This update mitigates the issue by adding the security check to the i915 driver. CVE-2019-11135It was discovered that on Intel CPUs supporting transactional memory (TSX), a transaction that is going to be aborted may continue to execute speculatively, reading sensitive data from internal buffers and leaking it through dependent operations. Intel calls this TSX Asynchronous Abort (TAA). For CPUs affected by the previously published Microarchitectural Data Sa ... Description truncated. Please see the references for more information.

'linux' package(s) on Debian Linux.

Checks if a vulnerable package version is present on the target host.

For the oldstable distribution (stretch), these problems have been fixed in version 4.9.189-3+deb9u2. For the stable distribution (buster), these problems have been fixed in version 4.19.67-2+deb10u2. We recommend that you upgrade your linux packages.