Bug 2509225 (CVE-2022-4994)

Summary: CVE-2022-4994 kernel: KVM: x86: wean fast IN from emulator_pio_in
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
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OS: Linux   
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Description OSIDB Bzimport 2026-07-30 10:01:25 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: wean fast IN from emulator_pio_in

Use __emulator_pio_in() directly for fast PIO instead of bouncing through
emulator_pio_in() now that __emulator_pio_in() fills "val" when handling
in-kernel PIO.  vcpu->arch.pio.count is guaranteed to be '0', so this a
pure nop.

emulator_pio_in_emulated is now the last caller of emulator_pio_in.

No functional change intended.
Comment 1 Mauro Matteo Cascella 2026-08-02 13:00:53 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026073058-CVE-2022-4994-07fd@gregkh/T