CVE-2026-90188

/// Technical description

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

null_blk: free global tag_set on init error path

If shared_tags is enabled, null_setup_tagset() allocates the global tag_set

via null_init_global_tag_set(). If device creation later fails, err_dev

destroys the default devices and calls unregister_blkdev(), but never frees

the global tag_set. Since module init failed, null_exit() is never invoked,

so the global tag_set's tags and maps are permanently leaked.

Free the global tag_set in err_dev, matching null_exit() which does

if (tag_set.ops) blk_mq_free_tag_set(&tag_set).

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References