CVE-2026-89535

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

svcrdma: Reorder rpcrdma_rn_unregister before rdma_destroy_id

svc_rdma_free() caches rdma->sc_cm_id->device before teardown,

then calls rdma_destroy_id(sc_cm_id) which frees the cm_id.

rpcrdma_rn_unregister() follows, but between those two calls

the transport's sc_rn entry is still installed in the device's

rd_xa. A concurrent ib_unregister_device walk can dispatch

svc_rdma_xprt_done() against the now-freed sc_cm_id.

Move rpcrdma_rn_unregister() before rdma_destroy_id() so the

transport's notification entry is removed from the xarray before

the cm_id it references is destroyed.

Also guard the sc_cm_id dereference with a NULL check: the

following patches introduce paths that reach svc_rdma_free()

with sc_cm_id == NULL (listener create failure, ADDR_CHANGE

replacement failure).

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References