======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/1:4/5724 is trying to acquire lock:
ffffffff914a2268 (rds_trans_sem){++++}-{4:4}, at: rds_trans_get_preferred+0x133/0x3c0 net/rds/transport.c:100

but task is already holding lock:
ffff888093184420 (&id_priv->handler_mutex/1){+.+.}-{4:4}, at: cma_ib_req_handler+0x2dd8/0x50d0 drivers/infiniband/core/cma.c:2450

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&id_priv->handler_mutex/1){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       cma_ib_req_handler+0x2dd8/0x50d0 drivers/infiniband/core/cma.c:2450
       cm_process_work+0x51/0x420 drivers/infiniband/core/cm.c:1869
       cm_req_handler drivers/infiniband/core/cm.c:2235 [inline]
       cm_work_handler+0x96c3/0xdff0 drivers/infiniband/core/cm.c:3849
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 (&id_priv->handler_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       rdma_destroy_id+0x1b/0x30 drivers/infiniband/core/cma.c:2124
       rds_ib_laddr_check_cm net/rds/ib.c:489 [inline]
       rds_ib_laddr_check+0x373/0x630 net/rds/ib.c:511
       rds_trans_get_preferred+0x179/0x3c0 net/rds/transport.c:104
       rds_bind+0x687/0x870 net/rds/bind.c:254
       __sys_bind_socket net/socket.c:1945 [inline]
       __sys_bind+0x2e3/0x410 net/socket.c:1976
       __do_sys_bind net/socket.c:1981 [inline]
       __se_sys_bind net/socket.c:1979 [inline]
       __x64_sys_bind+0x7a/0x90 net/socket.c:1979
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (rds_trans_sem){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
       down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
       rds_trans_get_preferred+0x133/0x3c0 net/rds/transport.c:100
       __rds_conn_create+0xa2c/0x2290 net/rds/connection.c:252
       rds_conn_create+0x43/0x60 net/rds/connection.c:384
       rds_ib_cm_handle_connect+0x446/0x1120 net/rds/ib_cm.c:860
       rds_rdma_cm_event_handler_cmn+0x691/0xa30 net/rds/rdma_transport.c:91
       cma_cm_event_handler+0xac/0x2c0 drivers/infiniband/core/cma.c:2181
       cma_ib_req_handler+0x3440/0x50d0 drivers/infiniband/core/cma.c:2461
       cm_process_work+0x51/0x420 drivers/infiniband/core/cm.c:1869
       cm_req_handler drivers/infiniband/core/cm.c:2235 [inline]
       cm_work_handler+0x96c3/0xdff0 drivers/infiniband/core/cm.c:3849
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

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 ***

locks held by kworker/1:4/5724: 4, last CPU#1:
 #0: ffff88802caa7140 ((wq_completion)ib_cm){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88802caa7140 ((wq_completion)ib_cm){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88802caa7140 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88802caa7140 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90004317c40 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90004317c40 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90004317c40 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90004317c40 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff888038ada420 (&id_priv->handler_mutex){+.+.}-{4:4}, at: cma_ib_req_handler+0x2188/0x50d0 drivers/infiniband/core/cma.c:2427
 #3: ffff888093184420 (&id_priv->handler_mutex/1){+.+.}-{4:4}, at: cma_ib_req_handler+0x2dd8/0x50d0 drivers/infiniband/core/cma.c:2450

stack backtrace:
CPU: 1 UID: 0 PID: 5724 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: ib_cm cm_work_handler
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
 rds_trans_get_preferred+0x133/0x3c0 net/rds/transport.c:100
 __rds_conn_create+0xa2c/0x2290 net/rds/connection.c:252
 rds_conn_create+0x43/0x60 net/rds/connection.c:384
 rds_ib_cm_handle_connect+0x446/0x1120 net/rds/ib_cm.c:860
 rds_rdma_cm_event_handler_cmn+0x691/0xa30 net/rds/rdma_transport.c:91
 cma_cm_event_handler+0xac/0x2c0 drivers/infiniband/core/cma.c:2181
 cma_ib_req_handler+0x3440/0x50d0 drivers/infiniband/core/cma.c:2461
 cm_process_work+0x51/0x420 drivers/infiniband/core/cm.c:1869
 cm_req_handler drivers/infiniband/core/cm.c:2235 [inline]
 cm_work_handler+0x96c3/0xdff0 drivers/infiniband/core/cm.c:3849
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>