Bug 2468146 (CVE-2026-43431)

Summary: CVE-2026-43431 kernel: xhci: Fix NULL pointer dereference when reading portli debugfs files
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
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 xhci host controller driver. This vulnerability occurs when the number of port registers counted in `xhci->max_ports` is greater than the ports reported by Supported Protocol capabilities. This can lead to a NULL pointer dereference, causing a kernel crash and resulting in a denial of service.
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Description OSIDB Bzimport 2026-05-08 15:01:33 UTC 
In the Linux kernel, the following vulnerability has been resolved:

xhci: Fix NULL pointer dereference when reading portli debugfs files

Michal reported and debgged a NULL pointer dereference bug in the
recently added portli debugfs files

Oops is caused when there are more port registers counted in
xhci->max_ports than ports reported by Supported Protocol capabilities.
This is possible if max_ports is more than maximum port number, or
if there are gaps between ports of different speeds the 'Supported
Protocol' capabilities.

In such cases port->rhub will be NULL so we can't reach xhci behind it.
Add an explicit NULL check for this case, and print portli in hex
without dereferencing port->rhub.
Comment 1 Keith Grant 2026-05-08 23:38:20 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050850-CVE-2026-43431-1c06@gregkh/T