UBUNTU-CVE-2025-38140: Medium severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: dm: limit swapping tables for devices with zone write plugs dmrevalidatezones() only allowed new or previously unzoned devices to call blkrevalidatediskzones(). If the device was already zoned, disk->nrzones would always equal md->nrzones, so dmrevalidatezones() returned without doing any work. This would make the zoned settings for the device not match the new table. If the device had zone write plug resources, it could run into errors like bdevzoneisseq() reading invalid memory because disk->convzonesbitmap was the wrong size. If the device doesn't have any zone write plug resources, calling blkrevalidatediskzones() will always correctly update device. If blkrevalidatediskzones() fails, it can still overwrite or clear the current disk->nrzones value. In this case, DM must restore the previous value of disk->nrzones, so that the zoned settings will continue to match the previous value that it fell back to. If the device already has zone write plug resources, blkrevalidatediskzones() will not correctly update them, if it is called for arbitrary zoned device changes. Since there is not much need for this ability, the easiest solution is to disallow any table reloads that change the zoned settings, for devices that already have zone plug resources. Specifically, if a device already has zone plug resources allocated, it can only switch to another zoned table that also emulates zone append. Also, it cannot change the device size or the zone size. A device can switch to an error target.