Linux Kernel: Critical Filesystem and Device Mapper Fixes

Transcript

Good morning, this is your Linux Kernel briefing for May 26th, 2026.

Today's activity focused entirely on critical bug fixes as the kernel approaches the 7.1 release. Linus Torvalds merged three separate fix tags addressing stability issues across multiple subsystems.

The most significant fix addresses a crash vulnerability in the HPFS filesystem when handling corrupted filesystems. Mikulas Patocka's patch prevents the kernel from calling hpfs_brelse4 on uninitialized quad buffer heads when hpfs_map_dnode_bitmap fails. This bug was reported by Farhad Alemi from Berkeley and has been tagged for stable kernel backporting.

The device mapper subsystem received a fix for the dm-vdo component, where GFP_NOWAIT allocation failures were causing crashes. The solution changes the allocation strategy to use GFP_NOIO for blkdev_issue_zeroout operations during the format path, ensuring more reliable memory allocation behavior.

Finally, the bootconfig tooling received a memory management fix from Masami Hiramatsu's team, addressing buffer leaks in the apply_xbc function. This prevents memory waste during boot configuration processing.

All fixes required minimal code changes - single-line modifications in most cases - but address potentially serious system stability issues. The HPFS fix is particularly notable as it prevents kernel crashes when mounting corrupted filesystems, a common attack vector.

What's next: These fixes suggest the 7.1 kernel is in the final stabilization phase, with focus shifting to critical bug resolution rather than feature development. Additional stability patches are likely as the release candidate cycle continues.

That's your kernel briefing. I'm your host, and we'll be back tomorrow with the latest developments.