====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/1:1/28 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: ffff88801d789420 (&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/1:1/28: #0: ffff88802c055538 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #0: ffff88802c055538 ((wq_completion)ib_cm){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #1: ffffc90000a4fd00 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc90000a4fd00 ((work_completion)(&(&work->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #2: ffff888026b94420 (&id_priv->handler_mutex){+.+.}-{3:3}, at: cma_ib_req_handler+0x2186/0x50b0 drivers/infiniband/core/cma.c:2407 #3: ffff88801d789420 (&id_priv->handler_mutex/1){+.+.}-{3:3}, at: cma_ib_req_handler+0x2dd4/0x50b0 drivers/infiniband/core/cma.c:2430 stack backtrace: CPU: 1 PID: 28 Comm: kworker/1:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: ib_cm cm_work_handler Call Trace: 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