Bluetooth: hci0: Opcode 0x0406 failed: -4 ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0 Not tainted ------------------------------------------------------ syz.1.2/6011 is trying to acquire lock: ffff88802a420840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:3922 [inline] ffff88802a420840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4176 [inline] ffff88802a420840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x4d0/0xcc0 kernel/workqueue.c:4208 but task is already holding lock: ffff88802a420b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 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}: __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 l2cap_info_timeout+0x79/0xa0 net/bluetooth/l2cap_core.c:1667 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 touch_work_lockdep_map kernel/workqueue.c:3922 [inline] start_flush_work kernel/workqueue.c:4176 [inline] __flush_work+0x4e4/0xcc0 kernel/workqueue.c:4208 __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4364 l2cap_conn_del+0x5af/0x730 net/bluetooth/l2cap_core.c:1795 l2cap_connect_cfm+0x9e1/0xf80 net/bluetooth/l2cap_core.c:7234 hci_connect_cfm include/net/bluetooth/hci_core.h:2052 [inline] hci_conn_failed+0x1ba/0x330 net/bluetooth/hci_conn.c:1269 hci_abort_conn_sync+0x740/0xb40 net/bluetooth/hci_sync.c:5616 hci_disconnect_all_sync.constprop.0+0x104/0x3c0 net/bluetooth/hci_sync.c:5639 hci_suspend_sync+0x770/0xab0 net/bluetooth/hci_sync.c:6116 hci_suspend_dev+0x308/0x500 net/bluetooth/hci_core.c:2812 hci_suspend_notifier+0x28d/0x2f0 net/bluetooth/hci_core.c:2392 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc8/0x160 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x231/0x6a0 fs/char_dev.c:414 do_dentry_open+0x741/0x1c10 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x1e5e/0x2d40 fs/namei.c:4039 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_compat_sys_openat fs/open.c:1506 [inline] __se_compat_sys_openat fs/open.c:1504 [inline] __ia32_compat_sys_openat+0x16d/0x210 fs/open.c:1504 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e 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.1.2/6011: #0: ffffffff8f0e2e08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x420 drivers/char/misc.c:143 #1: ffffffff8e283608 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 #2: ffffffff8e2c3150 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] #2: ffffffff8e2c3150 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xa8/0x160 kernel/notifier.c:333 #3: ffff88804c23cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_suspend_dev+0x300/0x500 net/bluetooth/hci_core.c:2811 #4: ffff88804c23c078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x146/0xb40 net/bluetooth/hci_sync.c:5597 #5: ffffffff90394808 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2049 [inline] ffffffff90394808 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x14f/0x330 net/bluetooth/hci_conn.c:1269 #6: ffff88802a420b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1761 #7: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4150 [inline] #7: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfb/0xcc0 kernel/workqueue.c:4208 stack backtrace: CPU: 2 UID: 0 PID: 6011 Comm: syz.1.2 Not tainted 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 touch_work_lockdep_map kernel/workqueue.c:3922 [inline] start_flush_work kernel/workqueue.c:4176 [inline] __flush_work+0x4e4/0xcc0 kernel/workqueue.c:4208 __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4364 l2cap_conn_del+0x5af/0x730 net/bluetooth/l2cap_core.c:1795 l2cap_connect_cfm+0x9e1/0xf80 net/bluetooth/l2cap_core.c:7234 hci_connect_cfm include/net/bluetooth/hci_core.h:2052 [inline] hci_conn_failed+0x1ba/0x330 net/bluetooth/hci_conn.c:1269 hci_abort_conn_sync+0x740/0xb40 net/bluetooth/hci_sync.c:5616 hci_disconnect_all_sync.constprop.0+0x104/0x3c0 net/bluetooth/hci_sync.c:5639 hci_suspend_sync+0x770/0xab0 net/bluetooth/hci_sync.c:6116 hci_suspend_dev+0x308/0x500 net/bluetooth/hci_core.c:2812 hci_suspend_notifier+0x28d/0x2f0 net/bluetooth/hci_core.c:2392 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc8/0x160 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x231/0x6a0 fs/char_dev.c:414 do_dentry_open+0x741/0x1c10 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x1e5e/0x2d40 fs/namei.c:4039 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_compat_sys_openat fs/open.c:1506 [inline] __se_compat_sys_openat fs/open.c:1504 [inline] __ia32_compat_sys_openat+0x16d/0x210 fs/open.c:1504 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf702e579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f501e55c EFLAGS: 00000296 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000800002c0 RDX: 0000000000007600 RSI: 000000000000feff RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi