Bug 2373353 (CVE-2025-38078)

Summary: CVE-2025-38078 kernel: Linux kernel: Use-After-Free vulnerability in PCM OSS layer due to race condition
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. A local attacker could exploit a race condition in the Pulse-Code Modulation (PCM) Open Sound System (OSS) layer's buffer access. This could lead to a use-after-free (UAF) vulnerability, where memory is accessed after it has been freed. This flaw may allow for information disclosure, privilege escalation, or arbitrary code execution.
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Description OSIDB Bzimport 2025-06-18 10:03:16 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ALSA: pcm: Fix race of buffer access at PCM OSS layer

The PCM OSS layer tries to clear the buffer with the silence data at
initialization (or reconfiguration) of a stream with the explicit call
of snd_pcm_format_set_silence() with runtime->dma_area.  But this may
lead to a UAF because the accessed runtime->dma_area might be freed
concurrently, as it's performed outside the PCM ops.

For avoiding it, move the code into the PCM core and perform it inside
the buffer access lock, so that it won't be changed during the
operation.
Comment 1 Avinash Hanwate 2025-06-20 19:34:34 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061841-CVE-2025-38078-3f10@gregkh/T