Linux 7.3-rc7 hardens mounts and schedules an ext4 mode for removal

Linus Torvalds published Linux 7.3-rc7 on 12 October 2026, about six hours later than planned. He had mixed up the day after traveling for the Kernel Maintainer Summit and Linux Plumbers Conference. The tag is still a fixes-only release. Final 7.3 is expected around 18 October if nothing large shows up.

The bulk of the visible work is in the virtual filesystem layer. Christian Brauner’s mount-namespace hardening accounts for the majority of the entries in this snapshot, including core fixes and the selftests that are supposed to keep those fixes from regressing. Mount namespaces are how containers keep one process’s view of the filesystem away from another’s. Bugs there are not cosmetic.

Two other changes are worth planning around. Theodore Ts’o marked ext4’s data=journal mode as deprecated, with removal aimed at January 2028. That mode journals both data and metadata. It is the strongest crash-consistency option ext4 offers, and also the slowest. Machines that still mount with it for safety-critical writes have a bit more than a year to move.

On the hardware side, rc7 takes Borislav Petkov’s workaround for AMD TLBI Erratum #1718, through Ingo Molnar’s urgent x86 tree. Some Zen processors can leave stale address translations behind. The kernel guard covers machines that do not yet have the matching microcode. It is expected to be backported to stable kernels.

None of this is a feature drop. It is the kind of late-cycle release that tells operators what to test before 7.3 goes stable: container mounts, any ext4 volume still using data journaling, and AMD boxes that have not taken the new microcode.