In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free The previous commit 0718a78f6a9f ("ALSA: usb-audio: Kill timer properly at removal") patched a UAF issue caused by the error timer. However, because the error timer kill added in this patch occurs after the endpoint delete, a race condition to UAF still occurs, albeit rarely. Additionally, since kill-cleanup for urb is also missing, freed memory can be accessed in interrupt context related to urb, which can cause UAF. Therefore, to prevent this, error timer and urb must be killed before freeing the heap memory.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/353d8c715cc951a980728133c9dd64ca5a0a186c cve-icon cve-icon
https://git.kernel.org/stable/c/647d6b8d22be12842fde6ed0c56859ebc615f21e cve-icon cve-icon
https://git.kernel.org/stable/c/9f2c0ac1423d5f267e7f1d1940780fc764b0fee3 cve-icon cve-icon
https://git.kernel.org/stable/c/af600e7f5526d16146b3ae99f6ad57bfea79ca33 cve-icon cve-icon
https://git.kernel.org/stable/c/dc4874366cf6cf4a31d8fa4b7f0e2a5b2d7647ba cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025101528-CVE-2025-39997-4384@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-39997 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-39997 cve-icon
History

Mon, 01 Dec 2025 06:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Mon, 20 Oct 2025 13:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Thu, 16 Oct 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Wed, 15 Oct 2025 08:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free The previous commit 0718a78f6a9f ("ALSA: usb-audio: Kill timer properly at removal") patched a UAF issue caused by the error timer. However, because the error timer kill added in this patch occurs after the endpoint delete, a race condition to UAF still occurs, albeit rarely. Additionally, since kill-cleanup for urb is also missing, freed memory can be accessed in interrupt context related to urb, which can cause UAF. Therefore, to prevent this, error timer and urb must be killed before freeing the heap memory.
Title ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-10-15T07:58:21.702Z

Updated: 2025-12-01T06:16:08.694Z

Reserved: 2025-04-16T07:20:57.151Z

Link: CVE-2025-39997

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-10-15T08:15:37.947

Modified: 2025-10-16T15:28:59.610

Link: CVE-2025-39997

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-10-15T00:00:00Z

Links: CVE-2025-39997 - Bugzilla