CVE-2025-38078 ALSA: pcm: Fix race of buffer access at PCM OSS layer
A race condition in the Linux kernel ALSA PCM OSS layer allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-38078?
CVE-2025-38078 is a high-severity use after free vulnerability in Debian Debian Linux, published on 18 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-362
Which versions are affected by CVE-2025-38078?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38078?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38078 being exploited?
There is no known exploitation of CVE-2025-38078 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-38078, DEBIAN-CVE-2025-38078, GHSA-8pc2-4qg2-6m45, ROOT-OS-DEBIAN-11-CVE-2025-38078, ROOT-OS-DEBIAN-12-CVE-2025-38078, ROOT-OS-UBUNTU-2204-CVE-2025-38078 and 2 more.