CVE-2026-89735 usb: gadget: midi2: remove default configfs groups on teardown
A memory leak in the Linux kernel USB MIDI2 gadget driver can lead to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89735?
CVE-2026-89735 is a memory corruption vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: midi2: remove default configfs groups on teardown
f_midi2_alloc_inst() creates default configfs child groups for the default endpoint and default block using configfs_add_default_group(), setting their internal refcount to 1.
However, during function teardown in f_midi2_free_inst() or EP cleanup in f_midi2_ep_opts_release(), configfs_remove_default_groups() is never called, therefore never dropping the refcount and leaking struct f_midi2_ep_opts and f_midi2_block_opts.
Add the missing configfs_remove_default_groups() in the afformentioned functions to free the structs properly.
Which versions are affected by CVE-2026-89735?
How do I fix CVE-2026-89735?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-89735 being exploited?
There is no known exploitation of CVE-2026-89735 in the wild and no public exploit code.
Sources
Also known as AZL-100608, BELL-CVE-2026-89735, DEBIAN-CVE-2026-89735, GHSA-c38q-5hmw-mm46, UBUNTU-CVE-2026-89735.