'Wednesday Greg Kroah-Hartman announced the release of the 6.4.2 kernel. "All users of the 6.4 kernel series must upgrade."

The Hacker News reports:

Details have emerged about a newly identified security flaw in the Linux kernel that could allow a user to gain elevated privileges on a target host. Dubbed StackRot (CVE-2023-3269, CVSS score: 7.8), the flaw impacts Linux versions 6.1 through 6.4. There is no evidence that the shortcoming has been exploited in the wild to date.

"As StackRot is a Linux kernel vulnerability found in the memory management subsystem, it affects almost all kernel configurations and requires minimal capabilities to trigger," Peking University security researcher Ruihan Li said. "However, it should be noted that maple nodes are freed using RCU callbacks, delaying the actual memory deallocation until after the RCU grace period. Consequently, exploiting this vulnerability is considered challenging."

Following responsible disclosure on June 15, 2023, it has been addressed in stable versions 6.1.37, 6.3.11, and 6.4.1 as of July 1, 2023, after a two-week effort led by Linus Torvalds. A proof-of-concept (PoC) exploit and additional technical specifics about the bug are expected to be made public by the end of the month.

ZDNet points out that Linux 6.4 "offers improved hardware enablement for ARM boards" and does a better job with the power demands of Steam Deck gaming devices. And "On the software side, the Linux 6.4 release includes more upstreamed Rust code. We're getting ever closer to full in-kernel Rust language support."

The Register also notes that Linux 6.4 also includes "the beginnings of support for Apple's M2 processors," along with support for hibernation of RISC-V CPUs, "a likely presage to such silicon powering laptop computers."'

-- source: https://linux.slashdot.org/story/23/07/09/0131210

Cheers, Peter