Kernel Drivers

Amazon Linux 2 — kernel-livepatch-4.14.355-280.651 — vulnerability — patch and remediation guide — diagnosis and fix on Amazon Linux 2

Amazon Linux 2 — kernel-livepatch-4.14.355-280.651 — vulnerability — patch and remediation guide

🟠 High   ⏱ 15–60 min  Last verified: 25 May 2026 Affected versions: Amazon Linux 2 📖 ~4 min read  •  Source: Amazon Linux advisory ALAS2LIVEPATCH-2025-251 Related CVEs: CVE-2022-49935 Upstream summary: In the Linux kernel, the following vulnerability has been resolved: dma-buf/dma-resv: check if the new fence is really later (CVE-2022-49935) Table of contents Symptom […]

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How to Configure SELinux on RHEL 8 — step-by-step RHEL 8 tutorial on Progressive Robot

How to Configure SELinux on RHEL 8

SELinux (Security-Enhanced Linux) is a mandatory access control (MAC) framework built into the Linux kernel and enabled by default on every RHEL 8 installation. Unlike discretionary access controls such as standard Unix permissions, SELinux enforces policy rules that confine processes to only the files, sockets, and capabilities they legitimately require, limiting the blast radius of […]

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Common Problems 118019

Ubuntu 18.04 LTS Docker Service Fails to Start

🟠 High   ⏱ 5–30 min  Last verified: 27 December 2022 Affected versions: 18.04 LTS 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & […]

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Oracle Linux 8 — Unbreakable Enterprise kernel — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — Unbreakable Enterprise kernel — vulnerability — patch and remediation guide (ELSA-2022-9689)

🟠 High   ⏱ 15–60 min  Last verified: 27 December 2022 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2022-9689 Related CVEs: CVE-2022-2588 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance […]

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How to Install PostgreSQL 16 on FreeBSD 12 — step-by-step FreeBSD 12 tutorial on Progressive Robot

How to Install PostgreSQL 16 on FreeBSD 12

Introduction How to Install PostgreSQL 16 on FreeBSD 12 is a core administration task for any FreeBSD 12 server operator. FreeBSD 12 ships with the 15.0-RELEASE kernel, ZFS as the default root filesystem, Capsicum capability sandboxing improvements, and an updated ports tree. Unlike Linux distributions, FreeBSD uses rc(8) for service management, pf for packet filtering, […]

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How to Implement Just-In-Time (JIT) Administration on Windows Server 2022 — step-by-step Windows Server 2022 tutorial on Progressive Robot

How to Implement Just-In-Time (JIT) Administration on Windows Server 2022

Introduction to Just-In-Time Administration on Windows Server 2022 Just-In-Time (JIT) administration is a security model that eliminates persistent privileged access. Instead of assigning administrators to privileged groups permanently, JIT grants elevated access only for a specific task window — typically minutes or hours — after which the privilege is automatically revoked. This dramatically reduces the […]

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How to Configure DirectAccess on Windows Server 2012 R2 — step-by-step Windows Server 2012 R2 tutorial on Progressive Robot

How to Configure DirectAccess on Windows Server 2012 R2

How to Configure DirectAccess on Windows Server 2012 R2 DirectAccess provides always-on, seamless remote access for domain-joined Windows clients without requiring user-initiated VPN connections. When a DirectAccess-configured client is outside the corporate network, it automatically establishes an encrypted tunnel to the DirectAccess server using IPv6 over HTTPS (IP-HTTPS) or other transition technologies, giving users transparent […]

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How to Set Up Windows Server Cluster-Aware Updating (CAU) on Windows Server 2022 — step-by-step Windows Server 2022 tutorial on Progressive Robot

How to Set Up Windows Server Cluster-Aware Updating (CAU) on Windows Server 2022

What Is Cluster-Aware Updating and Why It Matters Cluster-Aware Updating (CAU) is a Windows Server feature that automates the process of applying software updates to failover cluster nodes with zero planned downtime. Without CAU, patching a cluster requires a manual, error-prone procedure: drain one node, patch it, reboot, wait for it to rejoin, verify cluster […]

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Common Problems 117126

Ubuntu 22.04 kdump Fails to Capture Kernel Crash Dumps

🟡 Medium   ⏱ 5–30 min  Last verified: 24 December 2022 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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Common Problems 113052

Windows Server 2016 — Direct Server Return mode misconfiguration breaks SSL health probes in NLB — Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 24 December 2022 Affected versions: Windows Server 2016 📖 ~2 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution — Primary Fix Solution — Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors […]

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