CVE-2025-38078: ALSA: pcm: Fix race of buffer access at PCM OSS layer

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-06-18 · updated 2026-10-15
Weakness: CWE-362

Description

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.

Affected products

Debian Linux: 11.0
Linux kernel: before 5.4.294; from 5.5 before 5.10.238; from 5.11 before 5.15.185; from 5.16 before 6.1.141; from 6.2 before 6.6.93; from 6.7 before 6.12.31 — fixed in 5.10.238, 5.15.185, 5.4.294, 6.1.141, 6.12.31, 6.14.9

How to fix

Upgrade to a fixed version: Linux kernel 5.10.238, 5.15.185, 5.4.294, 6.1.141. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-38078 or the next vulnerability affects your stack