syzbot has found a reproducer for the following issue on: HEAD commit: d12d7e1cfe38 Add linux-next specific files for 20220411 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=162e29a8f00000 kernel config: https://syzkaller.appspot.com/x/.config?x=58fcaf7d8df169a6 dashboard link: https://syzkaller.appspot.com/bug?extid=b825d87fe2d043e3e652 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16a2ff0f700000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=149fd2df700000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b825d87fe2d043e3e652@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.18.0-rc1-next-20220411-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor104/3623 is trying to acquire lock: ffff88807bd9b130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1682 [inline] ffff88807bd9b130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_del+0x131/0x2c0 net/bluetooth/sco.c:197 but task is already holding lock: ffffffff8d777e08 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1580 [inline] ffffffff8d777e08 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1458 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hci_cb_list_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 hci_connect_cfm include/net/bluetooth/hci_core.h:1565 [inline] hci_remote_features_evt+0x62b/0xa20 net/bluetooth/hci_event.c:3736 hci_event_func net/bluetooth/hci_event.c:6890 [inline] hci_event_packet+0x7c1/0xf60 net/bluetooth/hci_event.c:6939 hci_rx_work+0x522/0xd60 net/bluetooth/hci_core.c:3819 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 -> #1 (&hdev->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 sco_sock_connect+0x1eb/0xa80 net/bluetooth/sco.c:593 __sys_connect_file+0x14f/0x190 net/socket.c:1900 __sys_connect+0x161/0x190 net/socket.c:1917 __do_sys_connect net/socket.c:1927 [inline] __se_sys_connect net/socket.c:1924 [inline] __x64_sys_connect+0x6f/0xb0 net/socket.c:1924 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 lock_sock_nested+0x36/0xf0 net/core/sock.c:3314 lock_sock include/net/sock.h:1682 [inline] sco_conn_del+0x131/0x2c0 net/bluetooth/sco.c:197 sco_disconn_cfm+0x71/0xb0 net/bluetooth/sco.c:1379 hci_disconn_cfm include/net/bluetooth/hci_core.h:1583 [inline] hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1458 hci_dev_close_sync+0x567/0x1140 net/bluetooth/hci_sync.c:4152 hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553 hci_rfkill_set_block+0x19c/0x1d0 net/bluetooth/hci_core.c:935 rfkill_set_block+0x1f9/0x540 net/rfkill/core.c:345 rfkill_fop_write+0x2c3/0x570 net/rfkill/core.c:1286 vfs_write+0x269/0xac0 fs/read_write.c:589 ksys_write+0x1e8/0x250 fs/read_write.c:644 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> &hdev->lock --> hci_cb_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hci_cb_list_lock); lock(&hdev->lock); lock(hci_cb_list_lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO); *** DEADLOCK *** 4 locks held by syz-executor104/3623: #0: ffffffff8d9583a8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x15c/0x570 net/rfkill/core.c:1278 #1: ffff888022e89048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551 #2: ffff888022e88078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x26d/0x1140 net/bluetooth/hci_sync.c:4139 #3: ffffffff8d777e08 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1580 [inline] #3: ffffffff8d777e08 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1458 stack backtrace: CPU: 0 PID: 3623 Comm: syz-executor104 Not tainted 5.18.0-rc1-next-20220411-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 lock_sock_nested+0x36/0xf0 net/core/sock.c:3314 lock_sock include/net/sock.h:1682 [inline] sco_conn_del+0x131/0x2c0 net/bluetooth/sco.c:197 sco_disconn_cfm+0x71/0xb0 net/bluetooth/sco.c:1379 hci_disconn_cfm include/net/bluetooth/hci_core.h:1583 [inline] hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1458 hci_dev_close_sync+0x567/0x1140 net/bluetooth/hci_sync.c:4152 hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553 hci_rfkill_set_block+0x19c/0x1d0 net/bluetooth/hci_core.c:935 rfkill_set_block+0x1f9/0x540 net/rfkill/core.c:345 rfkill_fop_write+0x2c3/0x570 net/rfkill/core.c:1286 vfs_write+0x269/0xac0 fs/read_write.c:589 ksys_write+0x1e8/0x250 fs/read_write.c:644 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f841a998629 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 15 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f841a1472f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f841aa214c0 RCX: 00007f841a998629 RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff20c0bcce R13: 00007fff20c0bccf R14: 00007f841aa214c8 R15: 0000000000022000 </TASK>
