Bluetooth: hci1: Opcode 0x0406 failed: -4 Bluetooth: hci1: Opcode 0x0406 failed: -4 Bluetooth: hci4: Opcode 0x0c1a failed: -4 Bluetooth: hci4: Opcode 0x0406 failed: -4 ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc7-syzkaller-00179-gb3ee1e460951 #0 Not tainted ------------------------------------------------------ syz.9.1128/10091 is trying to acquire lock: ffff88803331e840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] ffff88803331e840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffff88803331e840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4150 [inline] ffff88803331e840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0xe9/0xc60 kernel/workqueue.c:4208 but task is already holding lock: ffff88803331eb38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1761 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&conn->lock#2){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 l2cap_info_timeout+0x60/0xa0 net/bluetooth/l2cap_core.c:1667 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 touch_work_lockdep_map kernel/workqueue.c:3922 [inline] start_flush_work kernel/workqueue.c:4176 [inline] __flush_work+0x739/0xc60 kernel/workqueue.c:4208 __cancel_work_sync+0xbc/0x110 kernel/workqueue.c:4364 l2cap_conn_del+0x507/0x690 net/bluetooth/l2cap_core.c:1795 l2cap_connect_cfm+0x11f/0x1220 net/bluetooth/l2cap_core.c:7198 hci_connect_cfm include/net/bluetooth/hci_core.h:2029 [inline] hci_conn_failed+0x1d0/0x300 net/bluetooth/hci_conn.c:1266 hci_abort_conn_sync+0x59f/0xeb0 net/bluetooth/hci_sync.c:5588 hci_disconnect_all_sync+0x264/0x460 net/bluetooth/hci_sync.c:5611 hci_suspend_sync+0x41a/0xca0 net/bluetooth/hci_sync.c:6088 hci_suspend_dev+0x2be/0x4c0 net/bluetooth/hci_core.c:2812 hci_suspend_notifier+0xf2/0x2b0 net/bluetooth/hci_core.c:2392 notifier_call_chain+0x1a7/0x3f0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0xe8/0x1e0 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:102 snapshot_open+0x19b/0x280 kernel/power/user.c:77 misc_open+0x2ce/0x340 drivers/char/misc.c:179 chrdev_open+0x523/0x600 fs/char_dev.c:414 do_dentry_open+0xdee/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&conn->lock#2); lock((work_completion)(&(&conn->info_timer)->work)); lock(&conn->lock#2); lock((work_completion)(&(&conn->info_timer)->work)); *** DEADLOCK *** 8 locks held by syz.9.1128/10091: #0: ffffffff8f39a5c8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x54/0x340 drivers/char/misc.c:143 #1: ffffffff8e9ed368 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x60/0xa0 kernel/power/main.c:56 #2: ffffffff8ea0cbf0 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xac/0x1e0 kernel/notifier.c:344 #3: ffff888064ed0d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_suspend_dev+0x2b6/0x4c0 net/bluetooth/hci_core.c:2811 #4: ffff888064ed0078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1f2/0xeb0 net/bluetooth/hci_sync.c:5569 #5: ffffffff9003b928 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2026 [inline] #5: ffffffff9003b928 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x15d/0x300 net/bluetooth/hci_conn.c:1266 #6: ffff88803331eb38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1761 #7: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #7: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #7: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4150 [inline] #7: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xe9/0xc60 kernel/workqueue.c:4208 stack backtrace: CPU: 1 UID: 0 PID: 10091 Comm: syz.9.1128 Not tainted 6.14.0-rc7-syzkaller-00179-gb3ee1e460951 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 touch_work_lockdep_map kernel/workqueue.c:3922 [inline] start_flush_work kernel/workqueue.c:4176 [inline] __flush_work+0x739/0xc60 kernel/workqueue.c:4208 __cancel_work_sync+0xbc/0x110 kernel/workqueue.c:4364 l2cap_conn_del+0x507/0x690 net/bluetooth/l2cap_core.c:1795 l2cap_connect_cfm+0x11f/0x1220 net/bluetooth/l2cap_core.c:7198 hci_connect_cfm include/net/bluetooth/hci_core.h:2029 [inline] hci_conn_failed+0x1d0/0x300 net/bluetooth/hci_conn.c:1266 hci_abort_conn_sync+0x59f/0xeb0 net/bluetooth/hci_sync.c:5588 hci_disconnect_all_sync+0x264/0x460 net/bluetooth/hci_sync.c:5611 hci_suspend_sync+0x41a/0xca0 net/bluetooth/hci_sync.c:6088 hci_suspend_dev+0x2be/0x4c0 net/bluetooth/hci_core.c:2812 hci_suspend_notifier+0xf2/0x2b0 net/bluetooth/hci_core.c:2392 notifier_call_chain+0x1a7/0x3f0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0xe8/0x1e0 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:102 snapshot_open+0x19b/0x280 kernel/power/user.c:77 misc_open+0x2ce/0x340 drivers/char/misc.c:179 chrdev_open+0x523/0x600 fs/char_dev.c:414 do_dentry_open+0xdee/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f31c058d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f31c141a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f31c07a6080 RCX: 00007f31c058d169 RDX: 0000000000044000 RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f31c060e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f31c07a6080 R15: 00007fff25790ea8