CVE-2026-89535

Summary

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).

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxc4de97f7c45434985e5dbf2d6ccc9eca676e37fe < 9f2f5d0999364c7070306cd422d8babc2621070daffected
LinuxLinuxc4de97f7c45434985e5dbf2d6ccc9eca676e37fe < cfca6eb3345ba4a23cf9a1153ad09bf19faabfc9affected
LinuxLinuxc4de97f7c45434985e5dbf2d6ccc9eca676e37fe < 4488e912973773d64368828acf3b8e39d93650aeaffected
LinuxLinux6.12affected
LinuxLinux0 < 6.12unaffected
LinuxLinux6.18.51 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References