Hello, syzbot found the following issue on: HEAD commit: 20529233 Add linux-next specific files for 20201118 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=124ae36e500000 kernel config: https://syzkaller.appspot.com/x/.config?x=2c4fb58b6526b3c1 dashboard link: https://syzkaller.appspot.com/bug?extid=76c931ae5fdee51fff5b compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+76c931ae5fdee51fff5b@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.10.0-rc4-next-20201118-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/14971 is trying to acquire lock: ffff88801923e3b8 (&id_priv->handler_mutex){+.+.}-{3:3}, at: rdma_destroy_id+0x17/0x20 drivers/infiniband/core/cma.c:1904 but task is already holding lock: ffffffff8c684748 (lock#6){+.+.}-{3:3}, at: cma_add_one+0x55c/0xce0 drivers/infiniband/core/cma.c:4902 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (lock#6){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103 cma_acquire_dev_by_src_ip+0x1af/0x960 drivers/infiniband/core/cma.c:625 addr_handler+0x3d9/0x480 drivers/infiniband/core/cma.c:3160 process_one_req+0xfa/0x680 drivers/infiniband/core/addr.c:645 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 -> #0 (&id_priv->handler_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:2866 [inline] check_prevs_add kernel/locking/lockdep.c:2991 [inline] validate_chain kernel/locking/lockdep.c:3606 [inline] __lock_acquire+0x2ca6/0x5c00 kernel/locking/lockdep.c:4830 lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103 rdma_destroy_id+0x17/0x20 drivers/infiniband/core/cma.c:1904 cma_listen_on_dev.cold+0x168/0x16d drivers/infiniband/core/cma.c:2535 cma_add_one+0x667/0xce0 drivers/infiniband/core/cma.c:4905 add_client_context+0x405/0x5e0 drivers/infiniband/core/device.c:712 enable_device_and_get+0x1d5/0x3c0 drivers/infiniband/core/device.c:1333 ib_register_device drivers/infiniband/core/device.c:1408 [inline] ib_register_device+0x7a0/0xa30 drivers/infiniband/core/device.c:1367 siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline] siw_newlink drivers/infiniband/sw/siw/siw_main.c:545 [inline] siw_newlink+0xddb/0x1340 drivers/infiniband/sw/siw/siw_main.c:522 nldev_newlink+0x30e/0x540 drivers/infiniband/core/nldev.c:1555 rdma_nl_rcv_msg+0x367/0x690 drivers/infiniband/core/netlink.c:195 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x2f2/0x440 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:650 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:670 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2339 ___sys_sendmsg+0xf3/0x170 net/socket.c:2393 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2426 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#6); lock(&id_priv->handler_mutex); lock(lock#6); lock(&id_priv->handler_mutex); *** DEADLOCK *** 6 locks held by syz-executor.0/14971: #0: ffffffff8fa76958 (&rdma_nl_types[idx].sem){.+.+}-{3:3}, at: rdma_nl_rcv_msg+0x15b/0x690 drivers/infiniband/core/netlink.c:164 #1: ffffffff8c66c490 (link_ops_rwsem){++++}-{3:3}, at: nldev_newlink+0x261/0x540 drivers/infiniband/core/nldev.c:1545 #2: ffffffff8c65bd90 (devices_rwsem){++++}-{3:3}, at: enable_device_and_get+0xfc/0x3c0 drivers/infiniband/core/device.c:1321 #3: ffffffff8c65bc50 (clients_rwsem){++++}-{3:3}, at: enable_device_and_get+0x163/0x3c0 drivers/infiniband/core/device.c:1331 #4: ffff88806dbc8598 (&device->client_data_rwsem){++++}-{3:3}, at: add_client_context+0x3d0/0x5e0 drivers/infiniband/core/device.c:710 #5: ffffffff8c684748 (lock#6){+.+.}-{3:3}, at: cma_add_one+0x55c/0xce0 drivers/infiniband/core/cma.c:4902 stack backtrace: CPU: 1 PID: 14971 Comm: syz-executor.0 Not tainted 5.10.0-rc4-next-20201118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2115 check_prev_add kernel/locking/lockdep.c:2866 [inline] check_prevs_add kernel/locking/lockdep.c:2991 [inline] validate_chain kernel/locking/lockdep.c:3606 [inline] __lock_acquire+0x2ca6/0x5c00 kernel/locking/lockdep.c:4830 lock_acquire kernel/locking/lockdep.c:5435 [inline] lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5400 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103 rdma_destroy_id+0x17/0x20 drivers/infiniband/core/cma.c:1904 cma_listen_on_dev.cold+0x168/0x16d drivers/infiniband/core/cma.c:2535 cma_add_one+0x667/0xce0 drivers/infiniband/core/cma.c:4905 add_client_context+0x405/0x5e0 drivers/infiniband/core/device.c:712 enable_device_and_get+0x1d5/0x3c0 drivers/infiniband/core/device.c:1333 ib_register_device drivers/infiniband/core/device.c:1408 [inline] ib_register_device+0x7a0/0xa30 drivers/infiniband/core/device.c:1367 siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline] siw_newlink drivers/infiniband/sw/siw/siw_main.c:545 [inline] siw_newlink+0xddb/0x1340 drivers/infiniband/sw/siw/siw_main.c:522 nldev_newlink+0x30e/0x540 drivers/infiniband/core/nldev.c:1555 rdma_nl_rcv_msg+0x367/0x690 drivers/infiniband/core/netlink.c:195 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x2f2/0x440 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:650 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:670 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2339 ___sys_sendmsg+0xf3/0x170 net/socket.c:2393 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2426 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6cfdcbac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002d040 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fff0f7c1c9f R14: 00007f6cfdcbb9c0 R15: 000000000118bf2c --- This report is generated by a bot. 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