Bug 2525375 (CVE-2026-80689)

Summary: CVE-2026-80689 kernel: tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's mmiotrace component. When the `mmio_trace_array` is not initialized or is disabled, invoking `mmio_trace_rw()` or `mmio_trace_mapping()` can lead to a NULL pointer dereference. This can cause a system crash, resulting in a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-08-28 07:41:45 UTC 
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().
Comment 1 gkamathe 2026-08-31 07:23:02 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082803-CVE-2026-80689-f3d3@gregkh/T