Linux Kernel Daily: Critical EROFS and RCU Fixes

Transcript

Good morning, this is Linux Kernel Daily for May 21st, 2026.

Linus Torvalds has merged two critical fix sets targeting kernel 7.1 RC5 stability issues.

First, EROFS filesystem fixes from Gao Xiang address two significant problems. The merge resolves a kernel crash related to unaligned zstd extents in the managed cache system, along with a metabuf reference leak during shared xattr initialization. These fixes modify the xattr and zdata handling code to prevent filesystem corruption and crashes.

Second, RCU fixes from Boqun Feng tackle a regression introduced in the SRCU node allocation changes. The issue caused SRCU to queue work callbacks on CPUs that are marked as "possible" but have never actually been online. When these callbacks accumulate without execution, they trigger workqueue lockups. The fix ensures work handlers are only queued to CPUs that have been online at least once.

Both merges target core kernel stability, with the EROFS fixes preventing filesystem-level crashes and the RCU fixes addressing potential system lockups in CPU scheduling scenarios.

What's next: Additional RC5 fixes are likely as maintainers continue testing the current release candidate. The RCU regression fix may prompt further review of recent SRCU allocation changes.

That's your kernel update for today. I'm your host, and we'll be back tomorrow with the latest from kernel development.