A high‑severity Linux kernel flaw (CVE‑2026‑31431, dubbed "Copy Fail") allows ordinary users to gain root privileges and escape containers via an AF_ALG and splice() optimization bug, affecting major distributions; the article details the vulnerability, exploitation steps, PoC, and mitigation guidance.
This article explains why traditional I/O interfaces rely on data copying, demonstrates the hidden overhead of read/write in a network server, and introduces zero‑copy methods such as mmap, sendfile, DMA Gather Copy, and splice to dramatically reduce copies and context switches for faster I/O.
This article breaks down zero‑copy data transfer techniques—write+read, mmap+write, sendfile, sendfile + SG‑DMA, and splice—showing how they reduce CPU copies and context switches to boost I/O performance in modern operating systems.
This article explains the concept of zero‑copy in Linux, compares the four main system calls—sendfile, mmap, splice and tee—describes their APIs, internal mechanisms, performance characteristics, typical use‑cases and provides practical code examples for high‑performance network programming.
This article explains how Linux zero‑copy techniques—DMA, sendfile, splice, mmap + write, and tee—reduce CPU involvement in large file and network transfers by moving data directly within kernel space, detailing their workflows, code examples, performance trade‑offs, and suitable use cases.
This article explains how zero‑copy techniques such as mmap, sendfile, and splice reduce CPU involvement in data transfer by avoiding memory copies between kernel and user spaces, and shows how Java NIO and Netty implement these mechanisms for high‑performance backend I/O.
The article explains Linux zero‑copy I/O techniques—mmap, sendfile, splice, and tee—detailing their design principles, execution flows, context‑switch and data‑copy reductions, advantages, limitations, and appropriate use cases, helping developers choose the optimal method for high‑performance file and network transfers.
FUSE implements a user‑space file‑system framework where a kernel module creates the /dev/fuse device and forwards VFS requests into kernel queues, while a multi‑threaded daemon reads these requests, optionally uses splice for zero‑copy, processes them, and writes replies back, enabling simple file‑system development without kernel recompilation.
This article explains Linux's zero‑copy techniques—mmap, sendfile, and splice—detailing how they reduce data copies between user and kernel space, improve I/O efficiency, handle edge cases like SIGBUS, and leverage DMA to minimize CPU overhead in server file transfers.
This article explains why traditional read/write file serving incurs multiple data copies and context switches, then introduces mmap, sendfile, and splice as zero‑copy methods that reduce CPU load, discuss their usage, limitations, and practical pitfalls for high‑performance Linux servers.
