CVE-2026-90033

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.

References

• https://git.kernel.org/stable/c/1d4add2b832b56f81bb0eab065ec35c610343018
• https://git.kernel.org/stable/c/2dae0e3a59e31f78222279d544b98e747cd1fbff
• https://git.kernel.org/stable/c/5538daf2a5cc80ac3f3e913c0db045d92d995d40
• https://git.kernel.org/stable/c/9392a2c346762ffee8edd1ba8bac50d2e24a2ed7
• https://git.kernel.org/stable/c/9d81885d97cba7796d1f8edc88f2499c8296f5b9