CVE-2025-21870 ASoC: SOF: ipc4-topology: Harden loops for looking up ALH copiers
A null pointer dereference in the Linux kernel's SOF audio driver can cause a system crash when processing specific audio topology configurations.
- 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-2025-21870?
CVE-2025-21870 is a high-severity vulnerability in Linux kernel, published on 27 Mar 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:
ASoC: SOF: ipc4-topology: Harden loops for looking up ALH copiers
Other, non DAI copier widgets could have the same stream name (sname) as the ALH copier and in that case the copier->data is NULL, no alh_data is attached, which could lead to NULL pointer dereference. We could check for this NULL pointer in sof_ipc4_prepare_copier_module() and avoid the crash, but a similar loop in sof_ipc4_widget_setup_comp_dai() will miscalculate the ALH device count, causing broken audio.
The correct fix is to harden the matching logic by making sure that the 1. widget is a DAI widget - so dai = w->private is valid 2. the dai (and thus the copier) is ALH copier
Weakness: CWE-476
Which versions are affected by CVE-2025-21870?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21870?
Apply the vendor's patch.
Is CVE-2025-21870 being exploited?
There is no known exploitation of CVE-2025-21870 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-62845, BELL-CVE-2025-21870, DEBIAN-CVE-2025-21870, GHSA-fvjc-2g3g-9pm4, ROOT-OS-DEBIAN-12-CVE-2025-21870, ROOT-OS-UBUNTU-2404-CVE-2025-21870 and 1 more.