CVE-2026-68176 tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev
A local attacker with access to mmiotrace can cause a kernel crash by triggering a NULL pointer dereference when no PCI device is found.
- 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-2026-68176?
CVE-2026-68176 is a vulnerability in Linux, published on 10 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:
tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev
If the mmio_pipe_open() fails to find a PCI device, the hiter->dev will be assigned to NULL. The mmiotrace read() function dereferences the hiter->dev if hiter exists.
Change the test of the read to not only check hiter being NULL, but also the hiter->dev before dereferencing it.
Which versions are affected by CVE-2026-68176?
How do I fix CVE-2026-68176?
Apply the vendor's patch.
Is CVE-2026-68176 being exploited?
There is no known exploitation of CVE-2026-68176 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68176, DEBIAN-CVE-2026-68176, GHSA-ghxj-phm3-49fw, UBUNTU-CVE-2026-68176.