---
id: CVE-2026-90024
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  usb: gadget: midi2: Fix null-pointer dereference in f_midi2_free_ep_reqs

  A null-pointer dereference occurs in f_midi2_free_ep_reqs() when attempting
  to clean up an end…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  usb: gadget: midi2: Fix null-pointer dereference in f_midi2_free_ep_reqs

  A null-pointer dereference occurs in f_midi2_free_ep_reqs() when attempting
  to clean up an end…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8b645922b22303cec4628dbbbf6c8553d1cdec87 <
    51ddc55c75087ac25342f6d73d3aeaf14f59bd76
  - >-
    Linux >= 8b645922b22303cec4628dbbbf6c8553d1cdec87 <
    5b92f6a0c7c01efbb335d837ecdf34d38d98720f
  - >-
    Linux >= 8b645922b22303cec4628dbbbf6c8553d1cdec87 <
    9c3d5091e3568ed48ac4c5b08a78eb06fad0d70a
  - >-
    Linux >= 8b645922b22303cec4628dbbbf6c8553d1cdec87 <
    4079f19a0e1ce76f1e21a398f02aca150ceaaf61
  - >-
    Linux >= 8b645922b22303cec4628dbbbf6c8553d1cdec87 <
    f0efaf1872949e96d213c8e910fd9517f7d7c406
  - Linux 6.6
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T11:17:15.357'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90024'
references:
  - url: 'https://git.kernel.org/stable/c/4079f19a0e1ce76f1e21a398f02aca150ceaaf61'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/51ddc55c75087ac25342f6d73d3aeaf14f59bd76'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5b92f6a0c7c01efbb335d837ecdf34d38d98720f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9c3d5091e3568ed48ac4c5b08a78eb06fad0d70a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f0efaf1872949e96d213c8e910fd9517f7d7c406'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-16T10:53:53.936Z'
epss: 0.002
epssPercentile: 0.087
---

## Overview

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

usb: gadget: midi2: Fix null-pointer dereference in f_midi2_free_ep_reqs

A null-pointer dereference occurs in f_midi2_free_ep_reqs() when attempting
to clean up an endpoint that was never initialized.

When configuring the MIDI 2.0 gadget via configfs and setting the block
direction to SNDRV_UMP_DIR_INPUT, the initialization of the midi1_ep_out
endpoint is explicitly skipped during the gadget bind phase
(f_midi2_bind()). As a result, the usb_ep->card field remains NULL.

Later, when the host sets the alternate setting, f_midi2_set_alt()
unconditionally stops both the IN and OUT endpoints by calling
f_midi2_stop_eps(), which in turn calls f_midi2_free_ep_reqs() for both
endpoints. When f_midi2_free_ep_reqs() is called for the uninitialized
midi1_ep_out, it attempts to dereference usb_ep->card to determine the
number of requests to free, leading to a crash.

Fix this by using usb_ep->num_reqs instead of usb_ep->card->info.num_reqs
in f_midi2_free_ep_reqs(). usb_ep->num_reqs is correctly set during
f_midi2_init_ep() and remains 0 if the endpoint was never initialized,
safely avoiding the loop. For consistency, apply the same change to
f_midi2_alloc_ep_reqs().

Oops: general protection fault, probably for non-canonical address
0xdffffc00000000ee: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000770-0x0000000000000777]
...
RIP: 0010:f_midi2_free_ep_reqs drivers/usb/gadget/function/f_midi2.c:1166
[inline]
RIP: 0010:f_midi2_stop_eps+0x28e/0x4d0
drivers/usb/gadget/function/f_midi2.c:1246
...
Call Trace:
 <TASK>
 f_midi2_set_alt+0x11c/0xf00 drivers/usb/gadget/function/f_midi2.c:1296
 composite_setup+0x1ffd/0x3480 drivers/usb/gadget/composite.c:1933
 configfs_composite_setup+0xbd/0x100 drivers/usb/gadget/configfs.c:1877

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.