Description

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_midi: fix MIDI Streaming descriptor lengths

While the MIDI jacks are configured correctly, and the MIDIStreaming
endpoint descriptors are filled with the correct information,
bNumEmbMIDIJack and bLength are set incorrectly in these descriptors.

This does not matter when the numbers of in and out ports are equal, but
when they differ the host will receive broken descriptors with
uninitialized stack memory leaking into the descriptor for whichever
value is smaller.

The precise meaning of "in" and "out" in the port counts is not clearly
defined and can be confusing. But elsewhere the driver consistently
uses this to match the USB meaning of IN and OUT viewed from the host,
so that "in" ports send data to the host and "out" ports receive data
from it.

Classification

CVE ID: CVE-2025-21835

Affected Products

Vendor: Linux, Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 10.96% (scored less or equal to compared to others)

EPSS Date: 2025-04-05 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-21835
https://git.kernel.org/stable/c/9f6860a9c11301b052225ca8825f8d2b1a5825bf
https://git.kernel.org/stable/c/6ae6dee9f005a2f3b739b85abb6f14a0935699e0
https://git.kernel.org/stable/c/6b16761a928796e4b49e89a0b1ac284155172726
https://git.kernel.org/stable/c/a2d0694e1f111379c1efdf439dadd3cfd959fe9d
https://git.kernel.org/stable/c/da1668997052ed1cb00322e1f3b63702615c9429

Timeline