Description
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx
In __blk_mq_update_nr_hw_queues() the return value of blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx fails, later changing the number of hw_queues or removing disk will trigger the following warning:
kernfs: can not remove 'nr_tags', no directory WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160 Call Trace: remove_files.isra.1+0x38/0xb0 sysfs_remove_group+0x4d/0x100 sysfs_remove_groups+0x31/0x60 __kobject_del+0x23/0xf0 kobject_del+0x17/0x40 blk_mq_unregister_hctx+0x5d/0x80 blk_mq_sysfs_unregister_hctxs+0x94/0xd0 blk_mq_update_nr_hw_queues+0x124/0x760 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] nullb_device_submit_queues_store+0x92/0x120 [null_blk]
kobjct_del() was called unconditionally even if sysfs creation failed. Fix it by checkig the kobject creation statusbefore deleting it.
Metrics
No CVSS score has been published yet.
Affected software
No affected versions have been published.
Timeline
- Published
- Nov 12, 2025
- Last modified
- Oct 19, 2026
- NVD status
- Deferred