Language Selection

English French German Italian Portuguese Spanish

Kernel: LWN Coverage (No Longer Paywalled) and Initial HDMI 2.0 Support With Nouveau Slated For The Next Linux Kernel

Filed under
Linux
  • Revenge of the modems

    Back in the halcyon days of the previous century, those with a technical inclination often became overly acquainted with modems—not just the strange sounds they made when connecting, but the AT commands that were used to control them. While the AT command set is still in use (notably for GSM networks), it is generally hidden these days. But some security researchers have found that Android phones often make AT commands available via their USB ports, which is something that can potentially be exploited by rogue USB devices of various sorts.

    A paper [PDF] that was written by a long list of researchers (Dave (Jing) Tian, Grant Hernandez, Joseph I. Choi, Vanessa Frost, Christie Ruales, Patrick Traynor, Hayawardh Vijayakumar, Lee Harrison, Amir Rahmati, Michael Grace, and Kevin R. B. Butler) and presented at the 27th USENIX Security Symposium described the findings. A rather large number of Android firmware builds were scanned for the presence of AT commands and many were found to have them. That's not entirely surprising since the baseband processors used to communicate with the mobile network often use AT commands for configuration. But it turns out that Android vendors have also added their own custom AT commands that can have a variety of potentially harmful effects—making those available over USB is even more problematic.

    They started by searching through 2018 separate Android binary images (it is not clear how that number came about, perhaps it is simply coincidental) from 11 different vendors. They extracted and decompressed the various pieces inside the images and then searched those files for AT command strings. That process led to a database of 3500 AT commands, which can be seen at the web site for ATtention Spanned—the name given to the vulnerabilities.

  • XFS, LSM, and low-level management APIs

    The Linux Security Module (LSM) subsystem allows security modules to hook into many low-level operations within the kernel; modules can use those hooks to examine each requested operation and decide whether it should be allowed to proceed or not. In theory, just about every low-level operation is covered by an LSM hook; in practice, there are some gaps. A discussion regarding one of those gaps — low-level ioctl() operations on XFS filesystems — has revealed a thorny problem and a significant difference of opinion on what the correct solution is.

    In late September Tong Zhang pointed out that xfs_file_ioctl(), the 300-line function that dispatches the various ioctl() operations that can be performed on an XFS filesystem, was making a call to vfs_readlink() without first consulting the security_inode_readlink() LSM hook. As a result, a user with the privilege to invoke that operation (CAP_SYS_ADMIN) could read the value of a symbolic link within the filesystem, even if the security policy in place would otherwise forbid it. Zhang suggested that a call to the LSM hook should be added to address this problem.

  • Initial HDMI 2.0 Support With Nouveau Slated For The Next Linux Kernel

    Days after Nouveau DRM maintainer Ben Skeggs began staging changes for this open-source NVIDIA driver ahead of the next kernel cycle, this evening Ben Skeggs submitted the DRM-Next pull request to queue this work for the Linux 4.20/5.0 kernel cycle.

    As covered in that previous article, there isn't a whole lot on the Nouveau kernel driver front at this time. Skeggs summed up these open-source NVIDIA driver changes as: "Just initial HDMI 2.0 support, and a bunch of other cleanups."

  • Device-to-device memory-transfer offload with P2PDMA

    One of the most common tasks carried out by device drivers is setting up DMA operations for data transfers between main memory and the device. Often, data read into memory from one device will be immediately written, unchanged, to another device. Common examples include carrying the image between the camera and screen on a mobile phone, or downloading files to be saved on a disk. Those transfers have an impact on the CPU even if it does not use the data directly, due to higher memory use and effects like cache trashing. There are cases where it is possible to avoid usage of the system memory completely, though. A patch set (posted by Logan Gunthorpe with contributions by Christoph Hellwig and Steve Wise) has been in the works for some time that addresses this case for PCI devices using peer-to-peer (P2P) transfers, with a focus on offering an offload option for the NVMe fabrics target subsystem.

More in Tux Machines

digiKam 7.7.0 is released

After three months of active maintenance and another bug triage, the digiKam team is proud to present version 7.7.0 of its open source digital photo manager. See below the list of most important features coming with this release. Read more

Dilution and Misuse of the "Linux" Brand

Samsung, Red Hat to Work on Linux Drivers for Future Tech

The metaverse is expected to uproot system design as we know it, and Samsung is one of many hardware vendors re-imagining data center infrastructure in preparation for a parallel 3D world. Samsung is working on new memory technologies that provide faster bandwidth inside hardware for data to travel between CPUs, storage and other computing resources. The company also announced it was partnering with Red Hat to ensure these technologies have Linux compatibility. Read more

today's howtos

  • How to install go1.19beta on Ubuntu 22.04 – NextGenTips

    In this tutorial, we are going to explore how to install go on Ubuntu 22.04 Golang is an open-source programming language that is easy to learn and use. It is built-in concurrency and has a robust standard library. It is reliable, builds fast, and efficient software that scales fast. Its concurrency mechanisms make it easy to write programs that get the most out of multicore and networked machines, while its novel-type systems enable flexible and modular program constructions. Go compiles quickly to machine code and has the convenience of garbage collection and the power of run-time reflection. In this guide, we are going to learn how to install golang 1.19beta on Ubuntu 22.04. Go 1.19beta1 is not yet released. There is so much work in progress with all the documentation.

  • molecule test: failed to connect to bus in systemd container - openQA bites

    Ansible Molecule is a project to help you test your ansible roles. I’m using molecule for automatically testing the ansible roles of geekoops.

  • How To Install MongoDB on AlmaLinux 9 - idroot

    In this tutorial, we will show you how to install MongoDB on AlmaLinux 9. For those of you who didn’t know, MongoDB is a high-performance, highly scalable document-oriented NoSQL database. Unlike in SQL databases where data is stored in rows and columns inside tables, in MongoDB, data is structured in JSON-like format inside records which are referred to as documents. The open-source attribute of MongoDB as a database software makes it an ideal candidate for almost any database-related project. This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of the MongoDB NoSQL database on AlmaLinux 9. You can follow the same instructions for CentOS and Rocky Linux.

  • An introduction (and how-to) to Plugin Loader for the Steam Deck. - Invidious
  • Self-host a Ghost Blog With Traefik

    Ghost is a very popular open-source content management system. Started as an alternative to WordPress and it went on to become an alternative to Substack by focusing on membership and newsletter. The creators of Ghost offer managed Pro hosting but it may not fit everyone's budget. Alternatively, you can self-host it on your own cloud servers. On Linux handbook, we already have a guide on deploying Ghost with Docker in a reverse proxy setup. Instead of Ngnix reverse proxy, you can also use another software called Traefik with Docker. It is a popular open-source cloud-native application proxy, API Gateway, Edge-router, and more. I use Traefik to secure my websites using an SSL certificate obtained from Let's Encrypt. Once deployed, Traefik can automatically manage your certificates and their renewals. In this tutorial, I'll share the necessary steps for deploying a Ghost blog with Docker and Traefik.