====================================================== 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: 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 RDS/IB: Passive conn connected <::ffff:172.20.20.170,::ffff:172.20.20.170,0> version 3.1