Bug 2365279 (CVE-2025-37885)

Summary: CVE-2025-37885 kernel: KVM: x86: Reset IRTE to host control if *new* route isn't postable
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: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2025-05-09 07:03:09 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: Reset IRTE to host control if *new* route isn't postable

Restore an IRTE back to host control (remapped or posted MSI mode) if the
*new* GSI route prevents posting the IRQ directly to a vCPU, regardless of
the GSI routing type.  Updating the IRTE if and only if the new GSI is an
MSI results in KVM leaving an IRTE posting to a vCPU.

The dangling IRTE can result in interrupts being incorrectly delivered to
the guest, and in the worst case scenario can result in use-after-free,
e.g. if the VM is torn down, but the underlying host IRQ isn't freed.
Comment 1 Michal Findra 2025-05-09 07:33:35 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050945-CVE-2025-37885-a5d9@gregkh/T