program: r0 = syz_open_dev$tty1(0xc, 0x4, 0x1) ioctl$KDSETLED(r0, 0x4b32, 0x6) r1 = syz_init_net_socket$bt_l2cap(0x1f, 0x2, 0x0) connect$bt_l2cap(r1, &(0x7f0000000080)={0x1f, 0x0, @fixed={'\xaa\xaa\xaa\xaa\xaa', 0x10}, 0x7ff}, 0xe) r2 = socket$nl_route(0x10, 0x3, 0x0) sendmsg$nl_route(r2, &(0x7f0000000140)={0x0, 0x0, &(0x7f0000000080)={&(0x7f0000000240)=@newlink={0x20, 0x10, 0x801, 0x4, 0x0, {0x0, 0x0, 0x0, 0x0, 0x4}}, 0x20}}, 0x0) r3 = socket(0x10, 0x3, 0x0) r4 = socket$netlink(0x10, 0x3, 0x0) r5 = socket(0x10, 0x3, 0x0) sendmsg$nl_route_sched(r5, &(0x7f0000000000)={0x0, 0x0, &(0x7f0000000040)={0x0, 0x28}}, 0x0) getsockname$packet(r5, &(0x7f0000000100)={0x11, 0x0, 0x0, 0x1, 0x0, 0x6, @broadcast}, &(0x7f0000000200)=0x14) sendmsg$nl_route_sched(r4, &(0x7f0000001400)={0x0, 0x0, &(0x7f00000002c0)={&(0x7f0000000140)=@newqdisc={0x38, 0x24, 0xf0b, 0x0, 0x0, {0x0, 0x0, 0x0, r6, {}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_bfifo={{0xa}, {0x8}}]}, 0x38}}, 0x0) sendmsg$nl_route_sched(r3, &(0x7f0000000080)={0x0, 0x0, &(0x7f0000000380)={&(0x7f00000008c0)=@newqdisc={0x38, 0x24, 0x1, 0x0, 0x0, {0x0, 0x0, 0x0, r6, {}, {0xffff, 0xffff}}, [@qdisc_kind_options=@q_skbprio={{0xc}, {0x8}}]}, 0x38}}, 0x0) r7 = ioctl$TUNGETDEVNETNS(0xffffffffffffffff, 0x54e3, 0x0) setns(r7, 0x0) r8 = socket(0x10, 0x803, 0x0) ioctl$sock_SIOCETHTOOL(r8, 0x8946, &(0x7f0000000140)={'veth0_to_team\x00', &(0x7f0000000280)=@ethtool_channels={0x3d, 0x0, 0x0, 0x0, 0x4, 0x2, 0x1}}) r9 = syz_init_net_socket$bt_hidp(0x1f, 0x3, 0x6) ioctl$sock_bt_hidp_HIDPCONNADD(r9, 0x400448c8, &(0x7f00000000c0)={r1, r1, 0x206, 0x0, 0x0, 0x2, 0x72, 0x1, 0x3, 0x7, 0x0, 0x8, 'syz1\x00'}) r10 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) ioctl$HCIINQUIRY(r10, 0x400448ca, 0x0) [ 86.001240][ T5344] input: Bluetooth HID Boot Protocol Device as /devices/virtual/bluetooth/hci0/hci0:200/input5 [ 86.108790][ T5344] [ 86.109937][ T5344] ====================================================== [ 86.112862][ T5344] WARNING: possible circular locking dependency detected [ 86.116007][ T5344] syzkaller #0 Not tainted [ 86.117837][ T5344] ------------------------------------------------------ [ 86.120626][ T5344] syz.0.0/5344 is trying to acquire lock: [ 86.123192][ T5344] ffff888040d81840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0xd2/0xbc0 [ 86.128699][ T5344] [ 86.128699][ T5344] but task is already holding lock: [ 86.131957][ T5344] ffff888040d81b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 [ 86.135745][ T5344] [ 86.135745][ T5344] which lock already depends on the new lock. [ 86.135745][ T5344] [ 86.140228][ T5344] [ 86.140228][ T5344] the existing dependency chain (in reverse order) is: [ 86.144472][ T5344] [ 86.144472][ T5344] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 86.147929][ T5344] __mutex_lock+0x187/0x1350 [ 86.150210][ T5344] l2cap_info_timeout+0x60/0xa0 [ 86.152585][ T5344] process_scheduled_works+0xad1/0x1770 [ 86.155139][ T5344] worker_thread+0x8a0/0xda0 [ 86.157511][ T5344] kthread+0x711/0x8a0 [ 86.159599][ T5344] ret_from_fork+0x510/0xa50 [ 86.161838][ T5344] ret_from_fork_asm+0x1a/0x30 [ 86.164123][ T5344] [ 86.164123][ T5344] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 86.168672][ T5344] __lock_acquire+0x15a6/0x2cf0 [ 86.171150][ T5344] lock_acquire+0x107/0x340 [ 86.173430][ T5344] __flush_work+0x6b8/0xbc0 [ 86.175463][ T5344] __cancel_work_sync+0xbe/0x110 [ 86.177446][ T5344] l2cap_conn_del+0x402/0x5b0 [ 86.179383][ T5344] hci_conn_hash_flush+0x10d/0x260 [ 86.181325][ T5344] hci_dev_close_sync+0x821/0x1100 [ 86.183307][ T5344] hci_dev_close+0x108/0x270 [ 86.185150][ T5344] sock_do_ioctl+0xdc/0x300 [ 86.187245][ T5344] sock_ioctl+0x576/0x790 [ 86.189112][ T5344] __se_sys_ioctl+0xfc/0x170 [ 86.191181][ T5344] do_syscall_64+0xec/0xf80 [ 86.193234][ T5344] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.195616][ T5344] [ 86.195616][ T5344] other info that might help us debug this: [ 86.195616][ T5344] [ 86.199772][ T5344] Possible unsafe locking scenario: [ 86.199772][ T5344] [ 86.202558][ T5344] CPU0 CPU1 [ 86.204531][ T5344] ---- ---- [ 86.206738][ T5344] lock(&conn->lock#2); [ 86.208836][ T5344] lock((work_completion)(&(&conn->info_timer)->work)); [ 86.213210][ T5344] lock(&conn->lock#2); [ 86.216171][ T5344] lock((work_completion)(&(&conn->info_timer)->work)); [ 86.219289][ T5344] [ 86.219289][ T5344] *** DEADLOCK *** [ 86.219289][ T5344] [ 86.222936][ T5344] 5 locks held by syz.0.0/5344: [ 86.224999][ T5344] #0: ffff888011178ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x270 [ 86.228324][ T5344] #1: ffff8880111780c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 [ 86.232079][ T5344] #2: ffffffff8f485c88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 86.235849][ T5344] #3: ffff888040d81b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 [ 86.240700][ T5344] #4: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xd2/0xbc0 [ 86.245643][ T5344] [ 86.245643][ T5344] stack backtrace: [ 86.248198][ T5344] CPU: 0 UID: 0 PID: 5344 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 86.248213][ T5344] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 [ 86.248220][ T5344] Call Trace: [ 86.248228][ T5344] [ 86.248234][ T5344] dump_stack_lvl+0xe8/0x150 [ 86.248251][ T5344] print_circular_bug+0x2e2/0x300 [ 86.248267][ T5344] check_noncircular+0x12e/0x150 [ 86.248282][ T5344] __lock_acquire+0x15a6/0x2cf0 [ 86.248293][ T5344] ? do_raw_spin_lock+0x121/0x290 [ 86.248310][ T5344] ? __flush_work+0xd2/0xbc0 [ 86.248321][ T5344] lock_acquire+0x107/0x340 [ 86.248330][ T5344] ? __flush_work+0xd2/0xbc0 [ 86.248342][ T5344] ? __flush_work+0xd2/0xbc0 [ 86.248352][ T5344] __flush_work+0x6b8/0xbc0 [ 86.248362][ T5344] ? __flush_work+0xd2/0xbc0 [ 86.248373][ T5344] ? __flush_work+0xd2/0xbc0 [ 86.248384][ T5344] ? __pfx___flush_work+0x10/0x10 [ 86.248396][ T5344] ? __pfx_wq_barrier_func+0x10/0x10 [ 86.248410][ T5344] ? __cancel_work_sync+0x5c/0x110 [ 86.248420][ T5344] __cancel_work_sync+0xbe/0x110 [ 86.248431][ T5344] l2cap_conn_del+0x402/0x5b0 [ 86.248448][ T5344] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 86.248467][ T5344] hci_conn_hash_flush+0x10d/0x260 [ 86.248483][ T5344] hci_dev_close_sync+0x821/0x1100 [ 86.248496][ T5344] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 86.248506][ T5344] ? lockdep_hardirqs_on+0x7b/0x110 [ 86.248514][ T5344] ? enable_work+0x1e9/0x220 [ 86.248527][ T5344] hci_dev_close+0x108/0x270 [ 86.248539][ T5344] sock_do_ioctl+0xdc/0x300 [ 86.248551][ T5344] ? __pfx_sock_do_ioctl+0x10/0x10 [ 86.248564][ T5344] ? do_futex+0x395/0x420 [ 86.248574][ T5344] ? call_rcu+0x644/0x890 [ 86.248591][ T5344] sock_ioctl+0x576/0x790 [ 86.248604][ T5344] ? __pfx_sock_ioctl+0x10/0x10 [ 86.248615][ T5344] ? __fget_files+0x2a/0x420 [ 86.248625][ T5344] ? __fget_files+0x3a0/0x420 [ 86.248638][ T5344] ? __fget_files+0x2a/0x420 [ 86.248649][ T5344] ? bpf_lsm_file_ioctl+0x9/0x20 [ 86.248665][ T5344] ? __pfx_sock_ioctl+0x10/0x10 [ 86.248675][ T5344] __se_sys_ioctl+0xfc/0x170 [ 86.248689][ T5344] do_syscall_64+0xec/0xf80 [ 86.248699][ T5344] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.248708][ T5344] ? trace_irq_disable+0x37/0x100 [ 86.248723][ T5344] ? clear_bhb_loop+0x60/0xb0 [ 86.248735][ T5344] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 86.248746][ T5344] RIP: 0033:0x7fcadc38f7c9 [ 86.248758][ T5344] 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 [ 86.248769][ T5344] RSP: 002b:00007fcadd164038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 86.248780][ T5344] RAX: ffffffffffffffda RBX: 00007fcadc5e5fa0 RCX: 00007fcadc38f7c9 [ 86.248787][ T5344] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 000000000000000c [ 86.248793][ T5344] RBP: 00007fcadc413f91 R08: 0000000000000000 R09: 0000000000000000 [ 86.248799][ T5344] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 86.248804][ T5344] R13: 00007fcadc5e6038 R14: 00007fcadc5e5fa0 R15: 00007ffe2e3db2b8 [ 86.248814][ T5344] [ 86.378899][ T5317] Bluetooth: hci0: command tx timeout [ 88.411410][ T5317] Bluetooth: hci0: command tx timeout [ 90.491524][ T5317] Bluetooth: hci0: command tx timeout [ 91.853971][ T9] cfg80211: failed to load regulatory.db