CVE-2026-74647 misc: fastrpc: Remove buffer from list prior to unmap operation
A race condition in the Linux kernel fastrpc driver allows concurrent unmap operations to corrupt buffer state, potentially leading to undefined behavior.
- 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-2026-74647?
CVE-2026-74647 is a high-severity vulnerability in Linux, published on 22 Aug 2026. 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:
misc: fastrpc: Remove buffer from list prior to unmap operation
fastrpc_req_munmap_impl() is called to unmap any buffer. The buffer is getting removed from the list after it is unmapped from DSP. This can create potential race conditions if multiple threads invoke unmap concurrently, where one thread may remove the entry from the list while another thread's unmap operation is still ongoing.
Fix this by removing the buffer entry from the list before calling the unmap operation. If the unmap fails, the entry is re-added to the list so that userspace can retry the unmap, or alternatively, the buffer will be cleaned up during device release when the DSP process is torn down and all DSP-side mappings are freed along with remaining buffers in the list.
Which versions are affected by CVE-2026-74647?
How do I fix CVE-2026-74647?
Apply the vendor's patch.
Is CVE-2026-74647 being exploited?
There is no known exploitation of CVE-2026-74647 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74647, DEBIAN-CVE-2026-74647, GHSA-4jph-32qw-h3gw, UBUNTU-CVE-2026-74647.