6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 4488e912973773d64368828acf3b8e39d93650ae ] 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). Fixes: c4de97f7c454 ("svcrdma: Handle device removal outside of the CM event handler") Cc: stable@vger.kernel.org Acked-by: Jeff Layton Link: https://patch.msgid.link/20260527-rdma-follow-on-v1-2-1b09bd87b6cd@oracle.com Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xprtrdma/svc_rdma_transport.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -621,10 +621,15 @@ static void svc_rdma_free(struct svc_xpr { struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); - struct ib_device *device = rdma->sc_cm_id->device; + struct ib_device *device; might_sleep(); + if (!rdma->sc_cm_id) + goto out_free; + + device = rdma->sc_cm_id->device; + /* This blocks until the Completion Queues are empty */ if (rdma->sc_qp && !IS_ERR(rdma->sc_qp)) ib_drain_qp(rdma->sc_qp); @@ -649,11 +654,13 @@ static void svc_rdma_free(struct svc_xpr if (rdma->sc_pd && !IS_ERR(rdma->sc_pd)) ib_dealloc_pd(rdma->sc_pd); + if (!test_bit(XPT_LISTENER, &rdma->sc_xprt.xpt_flags)) + rpcrdma_rn_unregister(device, &rdma->sc_rn); + /* Destroy the CM ID */ rdma_destroy_id(rdma->sc_cm_id); - if (!test_bit(XPT_LISTENER, &rdma->sc_xprt.xpt_flags)) - rpcrdma_rn_unregister(device, &rdma->sc_rn); +out_free: kfree(rdma); }