CVE-2026-90022 usb: gadget: f_midi2: fix use-after-free in string attribute show path
A race condition in the Linux kernel USB MIDI gadget driver allows a local attacker to trigger a use-after-free, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90022?
CVE-2026-90022 is a high-severity use after free vulnerability in Linux, published on 16 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: f_midi2: fix use-after-free in string attribute show path
f_midi2_opts_str_show() takes the string lock internally, but its callers dereference the opts->info.<field> pointer before calling it, outside the lock. This races with f_midi2_opts_str_store(), which frees the old string under opts->lock when the attribute is written concurrently, the show path can read a pointer that gets freed before the lock inside str_show() is even taken.
Change f_midi2_opts_str_show() to take a pointer to the string field, matching the existing pattern in f_midi2_opts_str_store(), and dereference it only after the lock is held. Update all three callers (iface_name, block name, and the EP string option macro) accordingly.
Which versions are affected by CVE-2026-90022?
How do I fix CVE-2026-90022?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-90022 being exploited?
There is no known exploitation of CVE-2026-90022 in the wild and no public exploit code.
Sources
Also known as AZL-101373, BELL-CVE-2026-90022, DEBIAN-CVE-2026-90022, GHSA-3v5g-8x87-gm3v, UBUNTU-CVE-2026-90022.