CVE-2023-54022: ALSA: usb-audio: Fix potential memory leaks at error path for UMP open

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-24 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix potential memory leaks at error path for UMP open The allocation and initialization errors at alloc_midi_urbs() that is called at MIDI 2.0 / UMP device are supposed to be handled at the caller side by invoking free_midi_urbs(). However, free_midi_urbs() loops only for ep->num_urbs entries, and since ep->num_entries wasn't updated yet at the allocation / init error in alloc_midi_urbs(), this entry won't be released. The intention of free_midi_urbs() is to release the whole elements, so change the loop size to NUM_URBS to scan over all elements for fixing the missed releases. Also, the call of free_midi_urbs() is missing at snd_usb_midi_v2_open(). Although it'll be released later at reopen/close or disconnection, it's better to release immediately at the error path.

Affected products

Linux kernel: 6.5 — fixed in 6.6

How to fix

Upgrade to a fixed version: Linux kernel 6.6. Check the vendor advisory for mitigations.

References

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