CVE-2026-23376: nvmet-fcloop: Check remoteport port_state before calling done callback
In the Linux kernel, the following vulnerability has been resolved:
nvmet-fcloop: Check remoteport port_state before calling done callback
In nvme_fc_handle_ls_rqst_work, the lsrsp->done callback is only set when
remoteport->port_state is FC_OBJSTATE_ONLINE. Otherwise, the
nvme_fc_xmt_ls_rsp's LLDD call to lport->ops->xmt_ls_rsp is expected to
fail and the nvme-fc transport layer itself will directly call
nvme_fc_xmt_ls_rsp_free instead of relying on LLDD's done callback to free
the lsrsp resources.
Update the fcloop_t2h_xmt_ls_rsp routine to check remoteport->port_state.
If online, then lsrsp->done callback will free the lsrsp. Else, return
-ENODEV to signal the nvme-fc transport to handle freeing lsrsp.
Security readout for executives and security teams
Plain-English summary
This Linux kernel issue affects the NVMe Fibre Channel fcloop path. A port-state mismatch could cause response cleanup to rely on a callback that may not be set. The business risk is unclear because no severity, CVSS, CWE, or exploitation evidence is provided.
Executive priority
Track and patch through the normal kernel update process, with higher priority for storage infrastructure using NVMe-FC paths. There is insufficient evidence for emergency response.
Technical view
The fix changes fcloop_t2h_xmt_ls_rsp to check remoteport->port_state before using the lower-layer LS response flow. If the remote port is online, the done callback frees lsrsp; otherwise it returns -ENODEV so the nvme-fc transport frees lsrsp directly.
Likely exposure
Exposure appears limited to Linux systems running affected kernel versions with nvmet-fcloop or NVMe-FC transport paths in use. The source does not establish internet exposure or common default reachability.
Exploitation context
The CVE is not listed as KEV, and the supplied sources do not report active exploitation, public exploit code, or exploitation prerequisites. Treat exploitability as unproven from this bundle.
Researcher notes
The vulnerable behavior is in response cleanup logic around remoteport->port_state and lsrsp->done. The source bundle does not provide a crash signature, CVSS vector, CWE, or proof of exploitability, so validation should focus on affected code presence and fixed commit ancestry.
Mitigation direction
Apply Linux kernel updates containing the referenced stable fixes.
Prioritize hosts using NVMe-FC or nvmet-fcloop functionality.
Check distribution advisories for backported fixed kernel packages.
If unused, disable or avoid loading nvmet-fcloop per vendor guidance.
Validation and detection
Inventory running kernel versions across Linux hosts.
Check whether nvmet-fcloop or NVMe-FC modules are loaded or configured.
Map vendor kernels to the referenced stable commit fixes.
Review kernel logs for NVMe-FC errors around remote port state changes.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
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3Timeline events
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CVE reservedCVE Program
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CVE publishedCVE Program
The CVE record was published.
Mar 25, 2026, 10:27 UTC (UTC+00:00)
CVE updatedCVE Program
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