Linux Kernel 6.15 Released: Key Features & Updates
▼ Summary
– Linux 6.15 is released, featuring new hardware support, performance improvements, and expanded architecture extensions like Rust support for ARMv7 and RISC-V updates.
– Key updates include enhanced filesystem capabilities (e.g., FUSE handling long filenames), improved security hooks for io_uring, and new networking features like TCP_RTO_MAX_MS.
– Hardware support is expanded with drivers for devices like Apple Touch Bar, Google Pixel Pro 6, and HP laptops with CS35L41 audio chips.
– The update removes support for 32-bit x86 systems with over eight CPUs or 4GB RAM and introduces a new Landlock auditing mechanism for access denials.
– Linux 6.15 is available for download now, with the merge window for Linux 6.16 opening soon, expected by late July or early August 2025.
The latest stable Linux kernel, version 6.15, has officially launched, bringing a host of improvements that enhance performance, security, and hardware compatibility. This update introduces significant advancements across multiple subsystems, making it one of the most feature-rich releases in recent memory.
Key highlights include expanded Rust support for hrtimer and ARMv7 architectures, along with a new `setcpuid=` boot parameter for x86 processors. Virtualization gets a boost with nested VGICv3 support on ARM, while Apple Silicon gains emulation for FEAT_PMUv3. The kernel also introduces a fresh API for tracking filesystem mount and unmount events, giving developers better visibility into system operations.
Storage and security see notable upgrades, including hardware-wrapped encryption keys in the block layer and 48-bit block addressing for the EROFS filesystem. The iouring subsystem now benefits from a dedicated security hook, allowing finer control over permitted operations. Meanwhile, FUSE extends its capabilities by supporting filenames exceeding 1,024 characters, and OverlayFS introduces an `overridecreds` mount option for credential management.
Performance monitoring takes a leap forward with scheduler-based latency profiling in the perf subsystem, while BPF verification now handles loops more efficiently. Networking improvements include a new TCP socket option (`TCPRTOMAX_MS`) to adjust retransmission timeouts and BPF callbacks for timestamp retrieval across the networking stack.
RISC-V architecture gains multiple extensions, such as BFloat16, Zaamo, Zalrsc, and ZBKB, broadening its capabilities. XFS now supports zoned devices, and io_uring enables zero-copy network data reception, reducing overhead for high-performance applications.
On the hardware front, new drivers expand compatibility with devices like the Apple Touch Bar, Google Pixel Pro 6, and HP laptops using CS35L41 audio chips. The ACPI fan driver improves state handling, and the ACPI button driver now listens to system-wide event notifications, enhancing wake-from-sleep functionality.
Notable changes include the removal of 32-bit x86 support for systems with more than eight CPUs or 4GB of RAM. The Landlock security module introduces an auditing feature to simplify access denial analysis. A new `fwctl` subsystem enables secure firmware RPC execution, and a memory sealing feature—disabled by default—provides additional hardening against runtime modifications.
Users can download Linux 6.15 directly from kernel.org, though most will prefer waiting for their distribution to package the update. With this release finalized, development shifts toward Linux 6.16, expected in late July or early August. The first release candidate for testing will arrive in mid-June, offering early adopters a glimpse of what’s next.
(Source: 9to5Linux)