CVE-2026-80821
nvmet: pci-epf: put CQ ref on create_cq mapping failure
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.
INFO
Published Date :
Sept. 4, 2026, 4:18 p.m.
Last Modified :
Sept. 4, 2026, 4:18 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the provided kernel patch.
- Rebuild and install the kernel.
- Reboot the system to load the new kernel.
References to Advisories, Solutions, and Tools
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CVE-2026-80821.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-80821 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-80821
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-80821 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-80821 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 04, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80821.json">CVE-2026-80821</a> Added Reference https://git.kernel.org/stable/c/56a7b6a6880dbabe28214ff88df8d229ca3a944a Added Reference https://git.kernel.org/stable/c/659ae9d02cb5d72c76f74fff7441eb8fb64d8f5c Added Reference https://git.kernel.org/stable/c/b5f97fae2503a763fa0f953abf5f121b0fef7d0d Added Reference https://git.kernel.org/stable/c/f31650243c1ab32394077f234685e89ed8dece84