======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/0:9/4361 is trying to acquire lock:
ffffffff8e441c10 (rds_trans_sem){++++}-{3:3}, at: rds_trans_get_preferred+0x12f/0x3a0 net/rds/transport.c:100

but task is already holding lock:
ffff88807b3643b8 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x251a/0x4fd0 drivers/infiniband/core/cma.c:2270

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+0x1e5/0x2400 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       cma_ib_req_handler+0x251a/0x4fd0 drivers/infiniband/core/cma.c:2270
       cm_process_work+0x4b/0x410 drivers/infiniband/core/cm.c:1859
       cm_req_handler drivers/infiniband/core/cm.c:2222 [inline]
       cm_work_handler+0x9a26/0xeb30 drivers/infiniband/core/cm.c:3873
       process_one_work+0x867/0xff0 kernel/workqueue.c:2310
       worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
       kthread+0x42e/0x520 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

-> #1 (&id_priv->handler_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       rdma_destroy_id+0x17/0x20 drivers/infiniband/core/cma.c:1943
       rds_ib_laddr_check_cm net/rds/ib.c:491 [inline]
       rds_ib_laddr_check+0x3c1/0x680 net/rds/ib.c:513
       rds_trans_get_preferred+0x16f/0x3a0 net/rds/transport.c:104
       rds_bind+0x68c/0x870 net/rds/bind.c:254
       __sys_bind+0x2e9/0x3e0 net/socket.c:1730
       __do_sys_bind net/socket.c:1741 [inline]
       __se_sys_bind net/socket.c:1739 [inline]
       __x64_sys_bind+0x76/0x80 net/socket.c:1739
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (rds_trans_sem){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3120 [inline]
       check_prevs_add kernel/locking/lockdep.c:3239 [inline]
       validate_chain kernel/locking/lockdep.c:3855 [inline]
       __lock_acquire+0x38f7/0x7d40 kernel/locking/lockdep.c:5120
       lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       rds_trans_get_preferred+0x12f/0x3a0 net/rds/transport.c:100
       __rds_conn_create+0x9bc/0x1ea0 net/rds/connection.c:250
       rds_conn_create+0x3f/0x50 net/rds/connection.c:364
       rds_ib_cm_handle_connect+0x474/0x10d0 net/rds/ib_cm.c:860
       rds_rdma_cm_event_handler_cmn+0x454/0x8e0 net/rds/rdma_transport.c:85
       cma_cm_event_handler+0xa6/0x290 drivers/infiniband/core/cma.c:2000
       cma_ib_req_handler+0x2c49/0x4fd0 drivers/infiniband/core/cma.c:2281
       cm_process_work+0x4b/0x410 drivers/infiniband/core/cm.c:1859
       cm_req_handler drivers/infiniband/core/cm.c:2222 [inline]
       cm_work_handler+0x9a26/0xeb30 drivers/infiniband/core/cm.c:3873
       process_one_work+0x867/0xff0 kernel/workqueue.c:2310
       worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
       kthread+0x42e/0x520 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

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/0:9/4361:
 #0: ffff88814c416d38 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900031efd00 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff8880780be3b8 (&id_priv->handler_mutex){+.+.}-{3:3}, at: cma_ib_req_handler+0x2028/0x4fd0 drivers/infiniband/core/cma.c:2247
 #3: ffff88807b3643b8 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x251a/0x4fd0 drivers/infiniband/core/cma.c:2270

stack backtrace:
CPU: 0 PID: 4361 Comm: kworker/0:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: ib_cm cm_work_handler
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x400 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3120 [inline]
 check_prevs_add kernel/locking/lockdep.c:3239 [inline]
 validate_chain kernel/locking/lockdep.c:3855 [inline]
 __lock_acquire+0x38f7/0x7d40 kernel/locking/lockdep.c:5120
 lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737
 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
 rds_trans_get_preferred+0x12f/0x3a0 net/rds/transport.c:100
 __rds_conn_create+0x9bc/0x1ea0 net/rds/connection.c:250
 rds_conn_create+0x3f/0x50 net/rds/connection.c:364
 rds_ib_cm_handle_connect+0x474/0x10d0 net/rds/ib_cm.c:860
 rds_rdma_cm_event_handler_cmn+0x454/0x8e0 net/rds/rdma_transport.c:85
 cma_cm_event_handler+0xa6/0x290 drivers/infiniband/core/cma.c:2000
 cma_ib_req_handler+0x2c49/0x4fd0 drivers/infiniband/core/cma.c:2281
 cm_process_work+0x4b/0x410 drivers/infiniband/core/cm.c:1859
 cm_req_handler drivers/infiniband/core/cm.c:2222 [inline]
 cm_work_handler+0x9a26/0xeb30 drivers/infiniband/core/cm.c:3873
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
RDS/IB: Passive conn connected <::ffff:172.20.20.170,::ffff:172.20.20.170,0> version 3.1