======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/0:0/8 is trying to acquire lock:
ffffffff8f408690 (rds_trans_sem){++++}-{3:3}, at: rds_trans_get_preferred+0x133/0x3b0 net/rds/transport.c:100

but task is already holding lock:
ffff888032539420 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x2dd4/0x50b0 drivers/infiniband/core/cma.c:2430

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 kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
       cma_ib_req_handler+0x2dd4/0x50b0 drivers/infiniband/core/cma.c:2430
       cm_process_work+0x4b/0x410 drivers/infiniband/core/cm.c:1854
       cm_req_handler drivers/infiniband/core/cm.c:2220 [inline]
       cm_work_handler+0x9bbe/0xea50 drivers/infiniband/core/cm.c:3869
       process_one_work kernel/workqueue.c:2657 [inline]
       process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
       worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
       kthread+0x2fa/0x390 kernel/kthread.c:388
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

-> #1 (&id_priv->handler_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
       rdma_destroy_id+0x1b/0x30 drivers/infiniband/core/cma.c:2103
       rds_ib_laddr_check_cm net/rds/ib.c:491 [inline]
       rds_ib_laddr_check+0x3e1/0x6b0 net/rds/ib.c:513
       rds_trans_get_preferred+0x173/0x3b0 net/rds/transport.c:104
       rds_bind+0x690/0x870 net/rds/bind.c:254
       __sys_bind+0x2f0/0x3f0 net/socket.c:1856
       __do_sys_bind net/socket.c:1867 [inline]
       __se_sys_bind net/socket.c:1865 [inline]
       __x64_sys_bind+0x7a/0x90 net/socket.c:1865
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #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+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       rds_trans_get_preferred+0x133/0x3b0 net/rds/transport.c:100
       __rds_conn_create+0xa1e/0x1fe0 net/rds/connection.c:250
       rds_conn_create+0x43/0x60 net/rds/connection.c:364
       rds_ib_cm_handle_connect+0x478/0x10d0 net/rds/ib_cm.c:860
       rds_rdma_cm_event_handler_cmn+0x648/0x9a0 net/rds/rdma_transport.c:85
       cma_cm_event_handler+0xa6/0x290 drivers/infiniband/core/cma.c:2160
       cma_ib_req_handler+0x3435/0x50b0 drivers/infiniband/core/cma.c:2441
       cm_process_work+0x4b/0x410 drivers/infiniband/core/cm.c:1854
       cm_req_handler drivers/infiniband/core/cm.c:2220 [inline]
       cm_work_handler+0x9bbe/0xea50 drivers/infiniband/core/cm.c:3869
       process_one_work kernel/workqueue.c:2657 [inline]
       process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
       worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
       kthread+0x2fa/0x390 kernel/kthread.c:388
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

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/0:0/8:
 #0: ffff88802bef5138 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88802bef5138 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900000d7d00 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900000d7d00 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff888061601420 (&id_priv->handler_mutex){+.+.}-{3:3}, at: cma_ib_req_handler+0x2186/0x50b0 drivers/infiniband/core/cma.c:2407
 #3: ffff888032539420 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x2dd4/0x50b0 drivers/infiniband/core/cma.c:2430

stack backtrace:
CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted syzkaller #0
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+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 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+0x3a07/0x7eb0 kernel/locking/lockdep.c:5171
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
 rds_trans_get_preferred+0x133/0x3b0 net/rds/transport.c:100
 __rds_conn_create+0xa1e/0x1fe0 net/rds/connection.c:250
 rds_conn_create+0x43/0x60 net/rds/connection.c:364
 rds_ib_cm_handle_connect+0x478/0x10d0 net/rds/ib_cm.c:860
 rds_rdma_cm_event_handler_cmn+0x648/0x9a0 net/rds/rdma_transport.c:85
 cma_cm_event_handler+0xa6/0x290 drivers/infiniband/core/cma.c:2160
 cma_ib_req_handler+0x3435/0x50b0 drivers/infiniband/core/cma.c:2441
 cm_process_work+0x4b/0x410 drivers/infiniband/core/cm.c:1854
 cm_req_handler drivers/infiniband/core/cm.c:2220 [inline]
 cm_work_handler+0x9bbe/0xea50 drivers/infiniband/core/cm.c:3869
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
RDS/IB: Active conn connected <::ffff:172.20.20.170,::ffff:172.20.20.170,0> version 3.1
RDS/IB: Passive conn connected <::ffff:172.20.20.170,::ffff:172.20.20.170,0> version 3.1