CVE-2026-90033

ALSA: usb-audio: fix OOB write in snd_usbmidi_us122l_output()

Published Sep 16, 2026 CVSS n/a EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: fix OOB write in snd_usbmidi_us122l_output()

The snd_usbmidi_us122l_output() picks a count of 2 on anything slower
than high speed and never relates it to ep->max_transfer. The URB
buffer holds exactly max_transfer bytes, so a device declaring a one
byte bulk endpoint takes two bytes from snd_rawmidi_transmit(), and the
memset that pads the rest computes 1 - 2 in int and wraps to SIZE_MAX.

Only 0x800e and 0x800f are pinned to nine bytes. The US-122MKII at
0x0644:0x8021 falls to the default and takes usb_maxpacket(), which the
USB core only clamps downward.

The akai and novation output ops in this file were given the same guard
recently. Do the same here.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-8961-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9022-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9023-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9029-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-9039-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-119
CWE-122
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix OOB write in snd_usbmidi_us122l_output() The snd_usbmidi_us122l_output() picks a count of 2 on anything slower than high speed and never relates it to ep->max_transfer. The URB buffer holds exactly max_transfer bytes, so a device declaring a one byte bulk endpoint takes two bytes from snd_rawmidi_transmit(), and the memset that pads the rest computes 1 - 2 in int and wraps to SIZE_MAX. Only 0x800e and 0x800f are pinned to nine bytes. The US-122MKII at 0x0644:0x8021 falls to the default and takes usb_maxpacket(), which the USB core only clamps downward. The akai and novation output ops in this file were given the same guard recently. Do the same here.
Title ALSA: usb-audio: fix OOB write in snd_usbmidi_us122l_output()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 19, 2026, 8:56 AM
Reserved
Sep 11, 2026, 7:38 PM
Status
Received
Published
Sep 16, 2026, 11:17 AM
Modified
Oct 19, 2026, 9:18 AM