May 2024 - wlug - list.wlug.org.nz

AMD Core Performance Boost For Linux Getting Per-CPU Core Controls
by Peter Reutemann 13 May '24

13 May '24

'Phoronix: For the past several months AMD Linux engineers have been working on AMD Core Performance Boost support for their P-State CPU frequency scaling driver. The ninth iteration of these patches were posted on Monday and besides the global enabling/disabling support for Core Performance Boost, it's now possible to selectively toggle the feature on a per-CPU core basis... The new interface is under /sys/devices/system/cpu/cpuX/cpufreq/amd_pstate_boost_cpb for each CPU core. Thus users can tune whether particular CPU cores are boosted above the base frequency.' -- source: https://linux.slashdot.org/story/24/05/11/229219 Cheers, Peter

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Linux Kernel 6.9 Officially Released
by Peter Reutemann 13 May '24

13 May '24

'"6.9 is now out," Linus Torvalds posted on the Linux kernel mailing list, "and last week has looked quite stable (and the whole release has felt pretty normal)." Phoronix writes that Linux 6.9 "has a number of exciting features and improvements for those habitually updating to the newest version." And Slashdot reader prisoninmate shared this report from 9to5Linux: Highlights of Linux kernel 6.9 include Rust support on AArch64 (ARM64) architectures, support for the Intel FRED (Flexible Return and Event Delivery) mechanism for improved low-level event delivery, support for AMD SNP (Secure Nested Paging) guests, and a new dm-vdo (virtual data optimizer) target in device mapper for inline deduplication, compression, zero-block elimination, and thin provisioning. Linux kernel 6.9 also supports the Named Address Spaces feature in GCC (GNU Compiler Collection) that allows the compiler to better optimize per-CPU data access, adds initial support for FUSE passthrough to allow the kernel to serve files from a user-space FUSE server directly, adds support for the Energy Model to be updated dynamically at run time, and introduces a new LPA2 mode for ARM 64-bit processors... Linux kernel 6.9 will be a short-lived branch supported for only a couple of months. It will be succeeded by Linux kernel 6.10, whose merge window has now been officially opened by Linus Torvalds. Linux kernel 6.10 is expected to be released in mid or late September 2024. "Rust language has been updated to version 1.76.0 in Linux 6.9," according to the article. And Linus Torvalds shared one more details on the Linux kernel mailing list. "I now have a more powerful arm64 machine (thanks to Ampere), so the last week I've been doing almost as many arm64 builds as I have x86-64, and that should obviously continue during the upcoming merge window too."' -- source: https://linux.slashdot.org/story/24/05/12/2212235 Cheers, Peter

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Fedora Asahi Remix 40 is another big step forward for Linux on Apple Silicon Mac
by Peter Reutemann 10 May '24

10 May '24

'Asahi Linux, the project that aims to bring desktop Linux to Apple hardware with Apple silicon—the M series of chips—is out with Fedora Asahi Remix 40. More hardware features of Apple devices are supported, the Fedora Linux 40-based distro ships with KDE's new Plasma 6 desktop, and untold numbers of bugs are squashed, to be replaced with reams more. Fedora Asahi Remix is a "fully integrated distro," according to the Asahi team, and you can "expect a solid and high-quality experience without any unwanted surprises." It supports all the M1 and M2 devices in the MacBook, Mac Mini, Mac Studio, and iMac lines. It's OpenGL 4.6 and OpenGL ES 3.2 certified, and comes with "the best Linux laptop audio you've ever heard." So, should you install it on your Mac? Keep scrolling down Asahi's release page and check the "Device support" section. Still missing from most M-series Apple devices are support for Thunderbolt and USB4, built-in microphones, and Touch ID, as well as USB-C display support. Speakers are not supported on the iMac. And HDMI audio is in rough shape, being able to "break audio on the system completely." Still, for someone using an Apple laptop primarily as a portable device, or simply connecting to a monitor with less modern all-in-one cables, there is a desktop awaiting. Installing it is a single cURL command.' -- source: https://arstechnica.com/gadgets/2024/05/fedora-asahi-remix-40-is-another-bi… Cheers, Peter

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Raspberry Pis get a built-in remote access tool: Raspberry Pi Connect
by Peter Reutemann 08 May '24

08 May '24

'One Raspberry Pi often leads to another. Soon enough, you're running out of spots in your free RealVNC account for your tiny boards and "real" computers. Even if you go the hardened route of SSH or an X connection, you have to keep track of where they all are. All of this is not the easiest thing to tackle if you're new to single-board computers or just eager to get started. Enter Raspberry Pi Connect, a new built-in way to access a Rasbperry Pi from nearly anywhere you can open a browser, whether to control yourself or provide remote assistance. On a Raspberry Pi 4, 5, or Pi 400 kit, you install Pi connect with a single terminal line, reboot the Pi, and then click a new tray icon to connect the Pi to a Raspberry Pi ID (and then enable two-factor authentication, of course). >From then on, visiting connect.raspberrypi.com gives you an encrypted connection to your desktop. It's a direct connection if possible, and if not, it runs through relay servers in London, encrypting it with DTLS and keeping only the metadata needed for the service to work. The Pi will show a notification in its tray that somebody has connected, and you can manage screen sharing from there. The Pi's docs site has a lot more on the particulars. Connect works only on 64-bit systems running the Bookworm version of Pi OS with a Wayland window server. Connect was created partly due to Pi's transition to Wayland from X, which offered its own remote desktop option. According to the Pi firm, the service runs on a peer-to-peer WebRTC connection, similar to that of Zoom, Slack, Teams, and other video-sharing services. The whole service is in beta at the moment, and the company says it's not quite sure how much traffic to expect through its relay servers.' -- source: https://arstechnica.com/gadgets/2024/05/raspberry-pis-get-a-built-in-remote… Cheers, Peter

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Novel attack against virtually all VPN apps neuters their entire purpose
by Peter Reutemann 07 May '24

07 May '24

'Researchers have devised an attack against nearly all virtual private network applications that forces them to send and receive some or all traffic outside of the encrypted tunnel designed to protect it from snooping or tampering. TunnelVision, as the researchers have named their attack, largely negates the entire purpose and selling point of VPNs, which is to encapsulate incoming and outgoing Internet traffic in an encrypted tunnel and to cloak the user’s IP address. The researchers believe it affects all VPN applications when they’re connected to a hostile network and that there are no ways to prevent such attacks except when the user's VPN runs on Linux or Android. They also said their attack technique may have been possible since 2002 and may already have been discovered and used in the wild since then. The effect of TunnelVision is “the victim's traffic is now decloaked and being routed through the attacker directly,” a video demonstration explained. “The attacker can read, drop or modify the leaked traffic and the victim maintains their connection to both the VPN and the Internet.” The attack works by manipulating the DHCP server that allocates IP addresses to devices trying to connect to the local network. A setting known as option 121 allows the DHCP server to override default routing rules that send VPN traffic through a local IP address that initiates the encrypted tunnel. By using option 121 to route VPN traffic through the DHCP server, the attack diverts the data to the DHCP server itself.' -- source: https://arstechnica.com/security/2024/05/novel-attack-against-virtually-all… Cheers, Peter

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Kernel Modules Are Now Compressed
by Lawrence D'Oliveiro 06 May '24

06 May '24

Not sure if this is mentioned in any release notes anywhere, but the .ko files (loadable kernel modules) that would live in /lib/modules/«kernel version»/ are now .ko.xz files. Looks like this happened starting with the 6.6 kernel. I discovered this a few minutes ago, while trying to count how many .ko files came with my 6.7.9 Debian kernel, with find /lib/modules/$(uname -r) -name \*.ko | wc -l and was surprised to see that the answer was 0. A suitably adjusted command find /lib/modules/$(uname -r) -name \*.ko\* | wc -l returns 4165

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Yet Another New systemd Feature
by Lawrence D'Oliveiro 06 May '24

06 May '24

Lennart Poettering wants to get rid of sudo now, and replace it with a new systemd feature called “run0” <https://itwire.com/business-it-news/open-source/poettering-announces-tool-i…>. It is hard to write code that runs setuid, and sudo has had quite a few security vulnerabilities over the years. So Poettering’s idea is to replace the setuid executable with another use of the existing PolicyKit system. Interesting that Poettering thinks we should get rid of the whole idea of setuid altogether. AT&T actually got a patent on the concept, back in the early days of Unix. Other OSes had the concept of privileged code, but what made setuid different is that any user can set this mode on any executable they create, and when other users run this executable (if they are allowed to), they temporarily get the permissions of the owning user. On Linux, this concept was always constrained a bit: I think it only works on compiled machine-code executables, not on interpreted scripts.

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Maximum-Severity GitLab Flaw Allowing Account Hijacking Under Active Exploitation
by Peter Reutemann 03 May '24

03 May '24

'Dan Goodin reports via Ars Technica: A maximum severity vulnerability that allows hackers to hijack GitLab accounts with no user interaction required is now under active exploitation, federal government officials warned as data showed that thousands of users had yet to install a patch released in January. A change GitLab implemented in May 2023 made it possible for users to initiate password changes through links sent to secondary email addresses. The move was designed to permit resets when users didn't have access to the email address used to establish the account. In January, GitLab disclosed that the feature allowed attackers to send reset emails to accounts they controlled and from there click on the embedded link and take over the account. While exploits required no user interaction, hijackings worked only against accounts that weren't configured to use multi-factor authentication. Even with MFA, accounts remained vulnerable to password resets. The vulnerability, tracked as CVE-2023-7028, carries a severity rating of 10 out of a possible 10. The vulnerability, classified as an improper access control flaw, could pose a grave threat. GitLab software typically has access to multiple development environments belonging to users. With the ability to access them and surreptitiously introduce changes, attackers could sabotage projects or plant backdoors that could infect anyone using software built in the compromised environment. An example of a similar supply chain attack is the one that hit SolarWinds in 2021, infecting more than 18,000 of its customers. Other recent examples of supply chain attacks are here, here, and here. These sorts of attacks are powerful. By hacking a single, carefully selected target, attackers gain the means to infect thousands of downstream users, often without requiring them to take any action at all. According to Internet scans performed by security organization Shadowserver, more than 2,100 IP addresses showed they were hosting one or more vulnerable GitLab instances. In order to protect your system, you should enable MFA and install the latest patch. "GitLab users should also remember that patching does nothing to secure systems that have already been breached through exploits," notes Goodin.' -- source: https://it.slashdot.org/story/24/05/02/1934220 Cheers, Peter -- My Open Source Blog - http://open.fracpete.org

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Bat is a Modern Drop-in Replacement for Cat Command on Linux
by Peter Reutemann 01 May '24

01 May '24

'The bat is a modern command-line program written in the Rust programming language, and I can confidently say it’s a great drop-in replacement for our beloved cat command. If you’re wondering why I’m hyping this so much and what it has to offer you that makes it worth replacing the cat with, then do check out its features below. Bat really has some cool features to offer, which are mentioned below. - Supports syntax highlighting for a large number of programming and markup languages. - Detect and display Git changes. - Pipe output to its own pager (e.g., “less“) if the output is too large for one screen. - Display non-printable characters such as spaces, tabs, line breaks, etc. - Offer multiple themes that can be easily configured using flags or environments. - A user-friendly command-line interface that, of course, inherits all the functionality of the “cat” command.' -- source: https://linuxtldr.com/installing-bat/ Cheers, Peter

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