Bug 2528613 (CVE-2026-80821)

Summary: CVE-2026-80821 kernel: nvmet: pci-epf: put CQ ref on create_cq mapping failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's nvmet PCI Express Endpoint Function (PCI-EPF) component. A remote attacker can exploit this vulnerability by sending specially crafted Create IO Completion Queue (CQ) commands. This leads to a resource leak, as the system fails to properly release references to the completion queue and controller. Repeated exploitation of this flaw could result in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-04 15:43:44 UTC 
In the Linux kernel, the following vulnerability has been resolved:

nvmet: pci-epf: put CQ ref on create_cq mapping failure

nvmet_pci_epf_create_cq() calls nvmet_cq_create(), which takes a
reference on the controller and installs the completion queue. If the
subsequent PCI address-space mapping fails or returns a too-small partial
mapping, the function jumps to err_internal / err_unmap_queue without
calling nvmet_cq_put(). The matching put in nvmet_pci_epf_delete_cq() is
gated on NVMET_PCI_EPF_Q_LIVE, which is only set after the mapping
succeeds, so teardown never releases these references. A remote PCI host
that drives Create IO CQ commands with a failing PRP1/pci_addr therefore
leaks the CQ and a controller reference on each attempt.

Drop the CQ reference on the mapping-failure paths. The err_internal and
err_unmap_queue labels are only reachable after nvmet_cq_create() has
succeeded, so this pairs the create/put correctly.
Comment 1 gkamathe 2026-09-07 10:10:29 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80821.mbox