FAILED: patch "[PATCH] svcrdma: Clear sc_cm_id when ADDR_CHANGE replacement fails" failed to apply to 6.18-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 01500306e1d50de7ca7a2cdcdfa28ac0523eb747
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090325-lushness-making-8377@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 01500306e1d50de7ca7a2cdcdfa28ac0523eb747 Mon Sep 17 00:00:00 2001
From: Chuck Lever <cel@kernel.org>
Date: Wed, 27 May 2026 11:00:15 -0400
Subject: [PATCH] svcrdma: Clear sc_cm_id when ADDR_CHANGE replacement fails

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 <jlayton@kernel.org>
Link: https://patch.msgid.link/20260527-rdma-follow-on-v1-5-1b09bd87b6cd@oracle.com
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 656b2bd258a9..093371f9d245 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -330,6 +330,7 @@ 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;
@@ -638,7 +639,8 @@ 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(),