From f97d8c7bab7843631206a114986c9059da03efeb Mon Sep 17 00:00:00 2001 From: Aohan Mei Date: Fri, 11 Sep 2026 15:34:32 +0800 Subject: [PATCH] rds: ib: use rds_conn_drop() on protocol version mismatch rds_ib_cm_connect_complete() runs from the RDMA-CM event handler with conn->c_cm_lock held. When the peer negotiates a protocol version older than RDS_PROTOCOL_COMPAT_VERSION, the handler calls rds_conn_destroy(), which is only safe in the rmmod path: it synchronously tears the connection down and flush_work()es the shutdown work cp_down_w. That shutdown work (rds_conn_shutdown()) needs cp_cm_lock, which is the very lock the event handler still holds, so the flush never completes: the two workers wait on each other and the RDS connection workqueues stall for good. All other RDMA-CM failure paths (REJECTED, CONNECT_ERROR, DISCONNECTED) use rds_conn_drop(), which marks the connection RDS_CONN_ERROR and schedules the shutdown work asynchronously. Use it here as well. Fixes: f147dd9ecabf ("RDS/IB: Disallow connections less than RDS 3.1") Reported-by: TencentOS Corvus AI Cc: stable@vger.kernel.org Reviewed-by: Allison Henderson Signed-off-by: Aohan Mei Link: https://patch.msgid.link/20260911073436.3542080-1-ljp1205831794@gmail.com Signed-off-by: Jakub Kicinski --- net/rds/ib_cm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c index 4feb0edc360c..6e3110a04ae6 100644 --- a/net/rds/ib_cm.c +++ b/net/rds/ib_cm.c @@ -115,7 +115,7 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_even &conn->c_laddr, &conn->c_faddr, RDS_PROTOCOL_MAJOR(conn->c_version), RDS_PROTOCOL_MINOR(conn->c_version)); - rds_conn_destroy(conn); + rds_conn_drop(conn); return; } }