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.
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
Affected Vendors & Products
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
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 |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-15T07:58:21.702Z
Reserved: 2025-04-16T07:20:57.151Z
Link: CVE-2025-39997
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-10-15T08:15:37.947
Modified: 2025-10-15T08:15:37.947
Link: CVE-2025-39997
Redhat
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OpenCVE Enrichment
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