CVE-2026-80689 tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions
A NULL pointer dereference in the Linux kernel's mmiotrace logging functions can cause a system crash, requiring a kernel patch.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80689?
CVE-2026-80689 is a vulnerability in Linux, published on 28 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/mmiotrace: Add NULL check for mmio_trace_array in logging functions
mmio_trace_rw() and mmio_trace_mapping() retrieve mmio_trace_array into tr and pass it to __trace_mmiotrace_rw() and __trace_mmiotrace_map(). If these functions are invoked while mmio_trace_array is NULL (e.g. before initialization or after disabled), accessing tr->array_buffer.buffer will result in a NULL pointer dereference crash.
Fix this by adding an explicit NULL check for tr at the beginning of __trace_mmiotrace_rw() and __trace_mmiotrace_map().
Which versions are affected by CVE-2026-80689?
How do I fix CVE-2026-80689?
Apply the vendor's patch.
Is CVE-2026-80689 being exploited?
There is no known exploitation of CVE-2026-80689 in the wild and no public exploit code.
Sources
Also known as AZL-98175, BELL-CVE-2026-80689, DEBIAN-CVE-2026-80689, GHSA-6q77-h2mr-vrm4, UBUNTU-CVE-2026-80689.