batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface team0 (retrying later): interface not active ====================================================== WARNING: possible circular locking dependency detected 6.1.106-syzkaller #0 Not tainted ------------------------------------------------------ syz.3.303/5752 is trying to acquire lock: ffff0000d63ef130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1748 [inline] ffff0000d63ef130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_del+0xec/0x498 net/bluetooth/sco.c:201 but task is already holding lock: ffff800018131f68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1805 [inline] ffff800018131f68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb0/0x27c net/bluetooth/hci_conn.c:2441 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+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 hci_connect_cfm include/net/bluetooth/hci_core.h:1790 [inline] hci_remote_features_evt+0x458/0x8c4 net/bluetooth/hci_event.c:3803 hci_event_func net/bluetooth/hci_event.c:7539 [inline] hci_event_packet+0x744/0x109c net/bluetooth/hci_event.c:7591 hci_rx_work+0x318/0xa68 net/bluetooth/hci_core.c:4097 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2292 worker_thread+0x8e4/0xfec kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864 -> #1 (&hdev->lock){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 sco_sock_connect+0x170/0x84c net/bluetooth/sco.c:589 __sys_connect_file net/socket.c:2006 [inline] __sys_connect+0x268/0x290 net/socket.c:2023 __do_sys_connect net/socket.c:2033 [inline] __se_sys_connect net/socket.c:2030 [inline] __arm64_sys_connect+0x7c/0x94 net/socket.c:2030 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x3338/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 lock_sock_nested+0x78/0x138 net/core/sock.c:3485 lock_sock include/net/sock.h:1748 [inline] sco_conn_del+0xec/0x498 net/bluetooth/sco.c:201 sco_disconn_cfm+0x8c/0xdc net/bluetooth/sco.c:1375 hci_disconn_cfm include/net/bluetooth/hci_core.h:1808 [inline] hci_conn_hash_flush+0x104/0x27c net/bluetooth/hci_conn.c:2441 hci_dev_do_reset net/bluetooth/hci_core.c:575 [inline] hci_dev_reset+0x33c/0x534 net/bluetooth/hci_core.c:619 hci_sock_ioctl+0x444/0x82c net/bluetooth/hci_sock.c:1079 sock_do_ioctl+0x134/0x2dc net/socket.c:1204 sock_ioctl+0x4ec/0x858 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 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 *** 3 locks held by syz.3.303/5752: #0: ffff0000d91490b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_reset net/bluetooth/hci_core.c:548 [inline] #0: ffff0000d91490b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_reset+0xf8/0x534 net/bluetooth/hci_core.c:619 #1: ffff0000d9148078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_reset net/bluetooth/hci_core.c:573 [inline] #1: ffff0000d9148078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_reset+0x164/0x534 net/bluetooth/hci_core.c:619 #2: ffff800018131f68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1805 [inline] #2: ffff800018131f68 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb0/0x27c net/bluetooth/hci_conn.c:2441 stack backtrace: CPU: 1 PID: 5752 Comm: syz.3.303 Not tainted 6.1.106-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2048 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x3338/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 lock_sock_nested+0x78/0x138 net/core/sock.c:3485 lock_sock include/net/sock.h:1748 [inline] sco_conn_del+0xec/0x498 net/bluetooth/sco.c:201 sco_disconn_cfm+0x8c/0xdc net/bluetooth/sco.c:1375 hci_disconn_cfm include/net/bluetooth/hci_core.h:1808 [inline] hci_conn_hash_flush+0x104/0x27c net/bluetooth/hci_conn.c:2441 hci_dev_do_reset net/bluetooth/hci_core.c:575 [inline] hci_dev_reset+0x33c/0x534 net/bluetooth/hci_core.c:619 hci_sock_ioctl+0x444/0x82c net/bluetooth/hci_sock.c:1079 sock_do_ioctl+0x134/0x2dc net/socket.c:1204 sock_ioctl+0x4ec/0x858 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Bluetooth: hci0: Opcode 0x0c03 failed: -4