CVE-2026-90021

/// Technical description

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

usb: gadget: f_midi: initialize work in f_midi_alloc()

f_midi_alloc initializes free_ref to 1 and it can only be incremented

when a sound card is registered via f_midi_register_card().

f_midi_register_card() is only called in f_midi_bind() which actually

performs INIT_WORK. If f_midi_bind() is never run, work is not

initialized and the if condition in f_midi_free becomes true,

this results in a warning later in __flush_work as work->func = 0.

Fix this by moving INIT_WORK from f_midi_bind() to f_midi_alloc().

/// 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