In quite a rare departure from the norm, Linus Torvalds has noted that the second release candidate for Linux 7.0 is significantly larger than typical RC2 milestones, and he is not “super-happy” about it. While the founder of Linux attributed the bigger release to “random timing noise”, the amount of non-merge commits suggests a volatile start for the Linux 7.0 development cycle.
This release also diverges from the traditional driver-heavy pattern of early kernel candidates, with drivers only accounting for 25% of the total changes. Instead, the update is dominated by internal plumbing, including core kernel updates, networking, and filesystem changes that carry a higher-risk of system-wide instability.
This week, filesystem updates, specifically regarding SMB client, XFS, and EROFS, accounted for a quarter of the changes in the update. They focus on storage reliability with XFS alone receiving 19 separate patches that address everything from inode counter stats to potential pointer access races.
Security and memory management also got attention this week with fixes for KASAN (KernelAddressSANitizer) dynamic memory error detector hardware tag faults in the memory manager and speculative safety measures for x86 FRED (Flexible Return and Event Delivery). These low-level fixes are important for protecting against side-channel exploits.
The update also includes a large number of BPF (Berkeley Packet Filter) updates and related selftests which aim to refine how the kernel handles sandboxed programs. This week’s updates includes fixes for out of bounds writes and race conditions in PREEMPT_RT configurations.
Torvalds also mentioned that this update’s unusual size is likely a hangover effect from the Linux 6.19 cycle, which was extended by one week. This led to the creation of a bottleneck of pent-up work that has now flooded into Linux 7.0. Torvalds says he is looking for a quiet RC3 to confirm this week was random noise. If the next candidate is large as well then it could mean Linux 7.0 will see extra weeks of testing before the stable release arrives.