====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/1:3/4392 is trying to acquire lock: ffff800018caa470 (rds_trans_sem){++++}-{3:3}, at: rds_trans_get_preferred+0xfc/0x328 net/rds/transport.c:100 but task is already holding lock: ffff0000f563b420 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x1e14/0x4218 drivers/infiniband/core/cma.c:2407 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&id_priv->handler_mutex/1){+.+.}-{3:3}: __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 cma_ib_req_handler+0x1e14/0x4218 drivers/infiniband/core/cma.c:2407 cm_process_work+0x58/0x3f4 drivers/infiniband/core/cm.c:1854 cm_queue_work_unlock+0x11c/0x1fc drivers/infiniband/core/cm.c:917 cm_req_handler drivers/infiniband/core/cm.c:2220 [inline] cm_work_handler+0x7a48/0xd024 drivers/infiniband/core/cm.c:3869 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 -> #1 (&id_priv->handler_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 rdma_destroy_id+0x24/0x3c drivers/infiniband/core/cma.c:2080 rds_ib_laddr_check_cm net/rds/ib.c:491 [inline] rds_ib_laddr_check+0x3c4/0x4d0 net/rds/ib.c:513 rds_trans_get_preferred+0x134/0x328 net/rds/transport.c:104 rds_bind+0x4fc/0x6a4 net/rds/bind.c:254 __sys_bind+0x1f8/0x2a4 net/socket.c:1811 __do_sys_bind net/socket.c:1822 [inline] __se_sys_bind net/socket.c:1820 [inline] __arm64_sys_bind+0x7c/0x94 net/socket.c:1820 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (rds_trans_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3504/0x7280 kernel/locking/lockdep.c:5171 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790 down_read+0x64/0x300 kernel/locking/rwsem.c:1520 rds_trans_get_preferred+0xfc/0x328 net/rds/transport.c:100 __rds_conn_create+0x8bc/0x1944 net/rds/connection.c:250 rds_conn_create+0x60/0x7c net/rds/connection.c:364 rds_ib_cm_handle_connect+0x470/0xf88 net/rds/ib_cm.c:860 rds_rdma_cm_event_handler_cmn+0x3d8/0x7b4 net/rds/rdma_transport.c:85 rds_rdma_cm_event_handler+0x2c/0x3c net/rds/rdma_transport.c:186 cma_listen_handler+0x104/0x13c drivers/infiniband/core/cma.c:2674 cma_cm_event_handler+0xb8/0x400 drivers/infiniband/core/cma.c:2137 cma_ib_req_handler+0x2318/0x4218 drivers/infiniband/core/cma.c:2418 cm_process_work+0x58/0x3f4 drivers/infiniband/core/cm.c:1854 cm_queue_work_unlock+0x11c/0x1fc drivers/infiniband/core/cm.c:917 cm_req_handler drivers/infiniband/core/cm.c:2220 [inline] cm_work_handler+0x7a48/0xd024 drivers/infiniband/core/cm.c:3869 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 other info that might help us debug this: Chain exists of: rds_trans_sem --> &id_priv->handler_mutex --> &id_priv->handler_mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&id_priv->handler_mutex/1); lock(&id_priv->handler_mutex); lock(&id_priv->handler_mutex/1); rlock(rds_trans_sem); *** DEADLOCK *** 4 locks held by kworker/1:3/4392: #0: ffff0000d4022138 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1 #1: ffff8000224b7c40 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267 #2: ffff0000da7a3420 (&id_priv->handler_mutex){+.+.}-{3:3}, at: cma_ib_req_handler+0x1a98/0x4218 drivers/infiniband/core/cma.c:2384 #3: ffff0000f563b420 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x1e14/0x4218 drivers/infiniband/core/cma.c:2407 stack backtrace: CPU: 1 PID: 4392 Comm: kworker/1:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 Workqueue: ib_cm cm_work_handler Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2088 check_noncircular+0x290/0x370 kernel/locking/lockdep.c:2215 check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3504/0x7280 kernel/locking/lockdep.c:5171 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790 down_read+0x64/0x300 kernel/locking/rwsem.c:1520 rds_trans_get_preferred+0xfc/0x328 net/rds/transport.c:100 __rds_conn_create+0x8bc/0x1944 net/rds/connection.c:250 rds_conn_create+0x60/0x7c net/rds/connection.c:364 rds_ib_cm_handle_connect+0x470/0xf88 net/rds/ib_cm.c:860 rds_rdma_cm_event_handler_cmn+0x3d8/0x7b4 net/rds/rdma_transport.c:85 rds_rdma_cm_event_handler+0x2c/0x3c net/rds/rdma_transport.c:186 cma_listen_handler+0x104/0x13c drivers/infiniband/core/cma.c:2674 cma_cm_event_handler+0xb8/0x400 drivers/infiniband/core/cma.c:2137 cma_ib_req_handler+0x2318/0x4218 drivers/infiniband/core/cma.c:2418 cm_process_work+0x58/0x3f4 drivers/infiniband/core/cm.c:1854 cm_queue_work_unlock+0x11c/0x1fc drivers/infiniband/core/cm.c:917 cm_req_handler drivers/infiniband/core/cm.c:2220 [inline] cm_work_handler+0x7a48/0xd024 drivers/infiniband/core/cm.c:3869 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850