Bug 2378973 (CVE-2025-38249)

Summary: CVE-2025-38249 kernel: ALSA: usb-audio: Fix out-of-bounds read in snd_usb_get_audioformat_uac3()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-07-09 11:01:11 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: Fix out-of-bounds read in snd_usb_get_audioformat_uac3()

In snd_usb_get_audioformat_uac3(), the length value returned from
snd_usb_ctl_msg() is used directly for memory allocation without
validation. This length is controlled by the USB device.

The allocated buffer is cast to a uac3_cluster_header_descriptor
and its fields are accessed without verifying that the buffer
is large enough. If the device returns a smaller than expected
length, this leads to an out-of-bounds read.

Add a length check to ensure the buffer is large enough for
uac3_cluster_header_descriptor.
Comment 1 Jon Moroney 2025-07-09 17:59:59 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025070934-CVE-2025-38249-a6a3@gregkh/T