[PATCH net 2/2] net/rds: do not initialize transports after rds_init() failed
flat view
WARM2d
From: Allison Henderson <achender@kernel.org>
Date: 2026-10-21 19:58:40
Also in:
linux-rdma
Subsystem:
networking [general], rds - reliable datagram sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Allison Henderson, Linus Torvalds
rds, rds_rdma and rds_tcp each have their own module_init(). When they are built in, those run in link order, so rds_init() goes first, but do_initcalls() does not stop when it fails. The transports then initialize against a core that has already been torn down: rds_wq has been destroyed, yet rds_ib_dev_put(), rds_ib_unregister_client() and rds_tcp_accept_work() still queue onto or flush it, and rds_trans_register() hands the transports to a core whose socket family may never have been registered. This was seen with CONFIG_SYSCTL=n, where rds_sysctl_init() failed and rds_ib_init()'s error path then flushed the freed rds_wq [1], but any rds_init() failure after rds_threads_init() has the same effect. Record whether rds_init() succeeded and have rds_rdma_init() and rds_tcp_init() bail out with -ENODEV otherwise. Modular builds are unaffected: the transports need symbols exported by rds.ko, so they cannot be loaded unless rds_init() succeeded. [1] https://lore.kernel.org/oe-lkp/202610190310.9737b2e3-lkp@intel.com (local) Fixes: 55b7ed0b582f ("RDS: Common RDMA transport code") Fixes: 70041088e3b9 ("RDS: Add TCP transport to RDS") Suggested-by: Oleg Nesterov <oleg@redhat.com> Assisted-by: LLM Signed-off-by: Allison Henderson <achender@kernel.org> --- net/rds/af_rds.c | 14 ++++++++++++++ net/rds/rdma_transport.c | 3 +++ net/rds/rds.h | 1 + net/rds/tcp.c | 3 +++ 4 files changed, 21 insertions(+)
diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c
index d5defe9172e3..840587c05178 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c@@ -922,8 +922,11 @@ static void rds6_sock_info(struct socket *sock, unsigned int len, } #endif +static bool rds_initialized; + static void rds_exit(void) { + rds_initialized = false; sock_unregister(rds_family_ops.family); proto_unregister(&rds_proto); rds_conn_exit();
@@ -944,6 +947,16 @@ module_exit(rds_exit); u32 rds_gen_num; +/* When RDS is built in, a failed rds_init() does not stop the rds_rdma + * and rds_tcp initcalls from running against a core that has already + * been torn down (rds_wq in particular). Let them bail out early. + */ +bool rds_is_initialized(void) +{ + return rds_initialized; +} +EXPORT_SYMBOL_GPL(rds_is_initialized); + static int __init rds_init(void) { int ret;
@@ -980,6 +993,7 @@ static int __init rds_init(void) rds_info_register_func(RDS6_INFO_SOCKETS, rds6_sock_info); rds_info_register_func(RDS6_INFO_RECV_MESSAGES, rds6_sock_inc_info); #endif + rds_initialized = true; goto out;
diff --git a/net/rds/rdma_transport.c b/net/rds/rdma_transport.c
index 7be38be1228e..cc6a7d29791a 100644
--- a/net/rds/rdma_transport.c
+++ b/net/rds/rdma_transport.c@@ -325,6 +325,9 @@ static int __init rds_rdma_init(void) { int ret; + if (!rds_is_initialized()) + return -ENODEV; + ret = rds_ib_init(); if (ret) goto out;
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 2db49573dacd..b7ef7c8b1e03 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h@@ -1040,6 +1040,7 @@ extern unsigned int rds_sysctl_trace_level; int rds_threads_init(void); void rds_threads_exit(void); extern struct workqueue_struct *rds_wq; +bool rds_is_initialized(void); void rds_queue_reconnect(struct rds_conn_path *cp); void rds_connect_worker(struct work_struct *); void rds_shutdown_worker(struct work_struct *);
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 34815b4f658b..c1ad37505417 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c@@ -815,6 +815,9 @@ static int __init rds_tcp_init(void) { int ret; + if (!rds_is_initialized()) + return -ENODEV; + rds_tcp_conn_slab = KMEM_CACHE(rds_tcp_connection, 0); if (!rds_tcp_conn_slab) { ret = -ENOMEM;
--
2.50.1