Bug 2513208 (CVE-2026-68176)

Summary: CVE-2026-68176 kernel: tracing: Fix mmiotrace possible NULL dereferencing of hiter->dev
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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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 `mmio_pipe_open()` fails to find a PCI device, a null pointer is assigned to `hiter->dev`. The `mmiotrace read()` function then attempts to dereference this null pointer, which can lead to a system crash and result in a denial of service. A local attacker could potentially exploit this to cause system instability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-10 12:24:58 UTC 
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.