The vulnerability in the Linux kernel's Rust block code involved incomplete cleanup in the GenDiskBuilder::build() function. Specifically, after __blk_mq_alloc_disk(), error handling only recovered foreign queue data but leaked temporary gendisk and request_queue references. This leak could cause the blk-mq state to persist improperly if the last Arc<TagSet<T>> was moved into build(). The fix drops the temporary gendisk reference with put_disk() before recovering queue data, enabling disk_release() to fully tear down the queue. Furthermore, GenDisk::drop() was paired with put_disk() after del_gendisk() to ensure proper release of Rust GenDisk objects added via device_add_disk().

The vulnerability caused resource leaks in the Linux kernel block subsystem, specifically leaking temporary gendisk and request_queue references during error handling in GenDiskBuilder::build(). This could lead to retained blk-mq state beyond the lifetime of the tag set, potentially causing resource exhaustion or instability in the block device subsystem. No known exploits in the wild have been reported.

A fix has been implemented in the Linux kernel to address this issue by properly dropping temporary gendisk references and ensuring complete release of Rust GenDisk objects. Users should update to the fixed kernel versions once available. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.