6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever [ Upstream commit 01500306e1d50de7ca7a2cdcdfa28ac0523eb747 ] When svc_rdma_listen_handler() handles RDMA_CM_EVENT_ADDR_CHANGE, it creates a replacement listener cm_id and returns 1, telling the CM core to destroy the old one. If the replacement allocation fails, sc_cm_id still points at the old cm_id that the CM core is about to destroy. Any subsequent dereference of sc_cm_id -- such as svc_rdma_detach()'s rdma_disconnect() call -- is a use-after-free. NULL sc_cm_id on the failure path and guard svc_rdma_detach()'s rdma_disconnect() call against NULL so that the listener can be torn down safely when the server shuts down. Fixes: d1b586e75ec6 ("svcrdma: Handle ADDR_CHANGE CM event properly") Cc: stable@vger.kernel.org Acked-by: Jeff Layton Link: https://patch.msgid.link/20260527-rdma-follow-on-v1-5-1b09bd87b6cd@oracle.com Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- net/sunrpc/xprtrdma/svc_rdma_transport.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 767af51a782ed..b6044a1911ee9 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -325,6 +325,7 @@ static int svc_rdma_listen_handler(struct rdma_cm_id *cma_id, if (IS_ERR(listen_id)) { pr_err("Listener dead, address change failed for device %s\n", cma_id->device->name); + cma_xprt->sc_cm_id = NULL; } else cma_xprt->sc_cm_id = listen_id; return 1; @@ -630,7 +631,8 @@ static void svc_rdma_detach(struct svc_xprt *xprt) struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); - rdma_disconnect(rdma->sc_cm_id); + if (rdma->sc_cm_id) + rdma_disconnect(rdma->sc_cm_id); /* * Most close paths go through svc_rdma_xprt_deferred_close(), -- 2.53.0