program: socket$alg(0x26, 0x5, 0x0) r0 = gettid() r1 = syz_open_procfs(r0, &(0x7f0000000080)='net/ip_mr_cache\x00') r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000180), 0x2800, 0x0) ioctl$SG_BLKTRACESETUP(r1, 0xc0481273, &(0x7f00000001c0)={'\x00', 0x5, 0x8, 0xffffffff, 0x4d0, 0x6, r0}) r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0xd) r4 = ioctl$KVM_CREATE_VCPU(r3, 0xae41, 0x0) r5 = openat$fb0(0xffffffffffffff9c, &(0x7f0000000000), 0x0, 0x0) ioctl$FBIOPUT_VSCREENINFO(r5, 0x4601, &(0x7f0000000040)={0x80, 0xa0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, {0x10, 0x8}, {0x8, 0x8}, {}, {}, 0x0, 0x10, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x6, 0x0, 0x0, 0x0, 0x0, 0x2, 0x6}) ioctl$KVM_SET_MSRS(r4, 0xc008ae88, &(0x7f0000000040)={0x1, 0x0, [{0x40000100}]}) r6 = syz_init_net_socket$bt_l2cap(0x1f, 0x1, 0x3) r7 = syz_open_dev$midi(&(0x7f0000000000), 0x2, 0x0) ioctl$SNDRV_RAWMIDI_IOCTL_DRAIN(r7, 0x40045731, &(0x7f0000000100)=0x1) connect(r6, &(0x7f0000000000)=@rc={0x1f, @fixed={'\xaa\xaa\xaa\xaa\xaa', 0x10}, 0x8}, 0x80) r8 = syz_init_net_socket$bt_hci(0x1f, 0x3, 0x1) r9 = syz_genetlink_get_family_id$nl802154(&(0x7f0000000180), 0xffffffffffffffff) r10 = syz_init_net_socket$nl_generic(0x10, 0x3, 0x10) ioctl$sock_SIOCGIFINDEX_802154(r10, 0x8933, &(0x7f0000000ec0)={'wpan0\x00', 0x0}) sendmsg$NL802154_CMD_DEL_SEC_KEY(r10, &(0x7f0000000500)={0x0, 0x0, &(0x7f0000000080)={&(0x7f0000000380)={0x20, r9, 0x1, 0x0, 0x0, {}, [@NL802154_ATTR_IFINDEX={0x8, 0x3, r11}, @NL802154_ATTR_SEC_KEY={0x4}]}, 0x20}}, 0x0) ioctl$HCIINQUIRY(r8, 0x400448ca, 0x0) [ 85.365270][ T5325] [ 85.366384][ T5325] ====================================================== [ 85.369600][ T5325] WARNING: possible circular locking dependency detected [ 85.373071][ T5325] syzkaller #0 Not tainted [ 85.375371][ T5325] ------------------------------------------------------ [ 85.378604][ T5325] syz.0.0/5325 is trying to acquire lock: [ 85.381001][ T5325] ffff88803fdaa840 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}, at: __flush_work+0x100/0xc50 [ 85.385938][ T5325] [ 85.385938][ T5325] but task is already holding lock: [ 85.389469][ T5325] ffff88803fdaaaf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 85.393373][ T5325] [ 85.393373][ T5325] which lock already depends on the new lock. [ 85.393373][ T5325] [ 85.396903][ T5325] [ 85.396903][ T5325] the existing dependency chain (in reverse order) is: [ 85.400428][ T5325] [ 85.400428][ T5325] -> #1 (&conn->lock#2){+.+.}-{4:4}: [ 85.403520][ T5325] __mutex_lock+0x19f/0x1300 [ 85.405970][ T5325] l2cap_info_timeout+0x60/0xa0 [ 85.408747][ T5325] process_scheduled_works+0xb6e/0x18c0 [ 85.411623][ T5325] worker_thread+0xa53/0xfc0 [ 85.413801][ T5325] kthread+0x388/0x470 [ 85.415727][ T5325] ret_from_fork+0x51e/0xb90 [ 85.417865][ T5325] ret_from_fork_asm+0x1a/0x30 [ 85.420070][ T5325] [ 85.420070][ T5325] -> #0 ((work_completion)(&(&conn->info_timer)->work)){+.+.}-{0:0}: [ 85.424706][ T5325] __lock_acquire+0x15a5/0x2cf0 [ 85.427274][ T5325] lock_acquire+0xf0/0x2e0 [ 85.429433][ T5325] __flush_work+0x700/0xc50 [ 85.431874][ T5325] __cancel_work_sync+0xbe/0x110 [ 85.434274][ T5325] l2cap_conn_del+0x40f/0x5c0 [ 85.436547][ T5325] hci_conn_hash_flush+0x10d/0x260 [ 85.439131][ T5325] hci_dev_close_sync+0x821/0x10e0 [ 85.441924][ T5325] hci_dev_close+0x108/0x260 [ 85.444793][ T5325] sock_do_ioctl+0x101/0x320 [ 85.447872][ T5325] sock_ioctl+0x5c6/0x7f0 [ 85.450116][ T5325] __se_sys_ioctl+0xfc/0x170 [ 85.452298][ T5325] do_syscall_64+0x14d/0xf80 [ 85.454565][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.457641][ T5325] [ 85.457641][ T5325] other info that might help us debug this: [ 85.457641][ T5325] [ 85.462273][ T5325] Possible unsafe locking scenario: [ 85.462273][ T5325] [ 85.465674][ T5325] CPU0 CPU1 [ 85.468112][ T5325] ---- ---- [ 85.470553][ T5325] lock(&conn->lock#2); [ 85.472490][ T5325] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.477099][ T5325] lock(&conn->lock#2); [ 85.480464][ T5325] lock((work_completion)(&(&conn->info_timer)->work)); [ 85.483556][ T5325] [ 85.483556][ T5325] *** DEADLOCK *** [ 85.483556][ T5325] [ 85.487269][ T5325] 5 locks held by syz.0.0/5325: [ 85.490294][ T5325] #0: ffff88801bfe0ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_close+0x100/0x260 [ 85.494724][ T5325] #1: ffff88801bfe00c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 [ 85.498675][ T5325] #2: ffffffff8fd5c828 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 [ 85.503558][ T5325] #3: ffff88803fdaaaf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 [ 85.508299][ T5325] #4: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x100/0xc50 [ 85.512285][ T5325] [ 85.512285][ T5325] stack backtrace: [ 85.514888][ T5325] CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 85.514910][ T5325] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 85.514919][ T5325] Call Trace: [ 85.514927][ T5325] [ 85.514935][ T5325] dump_stack_lvl+0xe8/0x150 [ 85.514964][ T5325] print_circular_bug+0x2e1/0x300 [ 85.514986][ T5325] check_noncircular+0x12e/0x150 [ 85.515009][ T5325] __lock_acquire+0x15a5/0x2cf0 [ 85.515029][ T5325] ? do_raw_spin_lock+0x12b/0x2f0 [ 85.515045][ T5325] ? do_raw_spin_unlock+0x4d/0x210 [ 85.515058][ T5325] lock_acquire+0xf0/0x2e0 [ 85.515074][ T5325] ? __flush_work+0x100/0xc50 [ 85.515090][ T5325] ? __flush_work+0x100/0xc50 [ 85.515104][ T5325] __flush_work+0x700/0xc50 [ 85.515117][ T5325] ? __flush_work+0x100/0xc50 [ 85.515132][ T5325] ? __flush_work+0x100/0xc50 [ 85.515147][ T5325] ? __pfx___flush_work+0x10/0x10 [ 85.515162][ T5325] ? __pfx_wq_barrier_func+0x10/0x10 [ 85.515178][ T5325] ? __cancel_work_sync+0x5c/0x110 [ 85.515194][ T5325] __cancel_work_sync+0xbe/0x110 [ 85.515209][ T5325] l2cap_conn_del+0x40f/0x5c0 [ 85.515226][ T5325] ? __pfx_l2cap_disconn_cfm+0x10/0x10 [ 85.515251][ T5325] hci_conn_hash_flush+0x10d/0x260 [ 85.515275][ T5325] hci_dev_close_sync+0x821/0x10e0 [ 85.515294][ T5325] ? __pfx_hci_dev_close_sync+0x10/0x10 [ 85.515306][ T5325] ? lockdep_hardirqs_on+0x7a/0x110 [ 85.515317][ T5325] ? enable_work+0x1fd/0x230 [ 85.515336][ T5325] hci_dev_close+0x108/0x260 [ 85.515354][ T5325] sock_do_ioctl+0x101/0x320 [ 85.515368][ T5325] ? __pfx_sock_do_ioctl+0x10/0x10 [ 85.515381][ T5325] ? do_futex+0x333/0x420 [ 85.515404][ T5325] sock_ioctl+0x5c6/0x7f0 [ 85.515419][ T5325] ? __pfx_sock_ioctl+0x10/0x10 [ 85.515430][ T5325] ? __fget_files+0x2a/0x420 [ 85.515443][ T5325] ? __fget_files+0x3a0/0x420 [ 85.515456][ T5325] ? __fget_files+0x2a/0x420 [ 85.515474][ T5325] ? bpf_lsm_file_ioctl+0x9/0x20 [ 85.515489][ T5325] ? __pfx_sock_ioctl+0x10/0x10 [ 85.515501][ T5325] __se_sys_ioctl+0xfc/0x170 [ 85.515512][ T5325] do_syscall_64+0x14d/0xf80 [ 85.515524][ T5325] ? trace_irq_disable+0x3b/0x150 [ 85.515543][ T5325] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.515555][ T5325] ? clear_bhb_loop+0x40/0x90 [ 85.515570][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 85.515583][ T5325] RIP: 0033:0x7ff4dab9c799 [ 85.515598][ T5325] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 [ 85.515607][ T5325] RSP: 002b:00007ff4db9f9fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 85.515623][ T5325] RAX: ffffffffffffffda RBX: 00007ff4dae16090 RCX: 00007ff4dab9c799 [ 85.515633][ T5325] RDX: 0000000000000000 RSI: 00000000400448ca RDI: 000000000000000a [ 85.515642][ T5325] RBP: 00007ff4dac32c99 R08: 0000000000000000 R09: 0000000000000000 [ 85.515651][ T5325] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 85.515656][ T5325] R13: 00007ff4dae16128 R14: 00007ff4dae16090 R15: 00007fff12ad8038 [ 85.515668][ T5325] [ 85.663957][ T4666] Bluetooth: hci0: command tx timeout [ 87.679116][ T4666] Bluetooth: hci0: command tx timeout [ 89.758732][ T4666] Bluetooth: hci0: command tx timeout [ 91.926014][ T9] cfg80211: failed to load regulatory.db