CVE-2026-80821nvmet: pci-epf: put CQ ref on create_cq mapping failure

Official description

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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/f31650243c1ab32394077f234685e89ed8dece84
• https://git.kernel.org/stable/c/b5f97fae2503a763fa0f953abf5f121b0fef7d0d
• https://git.kernel.org/stable/c/56a7b6a6880dbabe28214ff88df8d229ca3a944a
• https://git.kernel.org/stable/c/659ae9d02cb5d72c76f74fff7441eb8fb64d8f5c