CVE-2026-64509

In the Linux kernel, the following vulnerability has been resolved:

rust: block: fix GenDisk cleanup paths

GenDiskBuilder::build() still has fallible work after

__blk_mq_alloc_disk(), but its error path only recovers the

foreign queue data. That leaks the temporary gendisk and

request_queue until later teardown. If the caller moved the last

Arc<TagSet<T>> into build(), the leaked queue can retain blk-mq

state after the tag set is dropped.

Fix the pre-registration failure path by dropping the temporary

gendisk reference with put_disk() before recovering queue_data,

so disk_release() can tear down the owned queue.

Also pair GenDisk::drop() with put_disk() after del_gendisk().

Once a Rust GenDisk has been added with device_add_disk(),

del_gendisk() only unregisters it; the final gendisk reference

still has to be dropped to complete the release path.