[ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.129' (ECDSA) to the list of known hosts. syzkaller login: [ 83.227351][ T28] audit: type=1400 audit(1596768889.078:8): avc: denied { execmem } for pid=6844 comm="syz-executor287" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 83.243148][ T6845] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 85.816729][ T1537] ------------[ cut here ]------------ [ 85.822615][ T1537] refcount_t: addition on 0; use-after-free. [ 85.829537][ T1537] WARNING: CPU: 1 PID: 1537 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 [ 85.839028][ T1537] Kernel panic - not syncing: panic_on_warn set ... [ 85.845641][ T1537] CPU: 1 PID: 1537 Comm: kworker/u5:0 Not tainted 5.8.0-syzkaller #0 [ 85.854053][ T1537] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 85.864757][ T1537] Workqueue: hci0 hci_rx_work [ 85.869458][ T1537] Call Trace: [ 85.872794][ T1537] dump_stack+0x18f/0x20d [ 85.877152][ T1537] panic+0x2e3/0x75c [ 85.881076][ T1537] ? __warn_printk+0xf3/0xf3 [ 85.885696][ T1537] ? lockdep_hardirqs_on+0x76/0xf0 [ 85.890832][ T1537] ? __warn.cold+0x5/0x45 [ 85.895198][ T1537] ? __warn+0xd6/0x1f2 [ 85.899305][ T1537] ? refcount_warn_saturate+0x169/0x1e0 [ 85.904883][ T1537] __warn.cold+0x20/0x45 [ 85.909142][ T1537] ? wake_up_klogd.part.0+0x8c/0xc0 [ 85.914375][ T1537] ? refcount_warn_saturate+0x169/0x1e0 [ 85.919960][ T1537] report_bug+0x1bd/0x210 [ 85.924321][ T1537] handle_bug+0x38/0x90 [ 85.928515][ T1537] exc_invalid_op+0x14/0x40 [ 85.933070][ T1537] asm_exc_invalid_op+0x12/0x20 [ 85.937993][ T1537] RIP: 0010:refcount_warn_saturate+0x169/0x1e0 [ 85.944249][ T1537] Code: 07 31 ff 89 de e8 97 7f db fd 84 db 0f 85 36 ff ff ff e8 4a 83 db fd 48 c7 c7 a0 83 93 88 c6 05 9a da 13 07 01 e8 a9 94 ac fd <0f> 0b e9 17 ff ff ff e8 2b 83 db fd 0f b6 1d 7f da 13 07 31 ff 89 [ 85.963993][ T1537] RSP: 0018:ffffc900057f7908 EFLAGS: 00010286 [ 85.970085][ T1537] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 85.978090][ T1537] RDX: ffff8880a4424080 RSI: ffffffff815d8eb7 RDI: fffff52000afef13 [ 85.986081][ T1537] RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880ae731927 [ 85.994084][ T1537] R10: 0000000000000000 R11: 0000000033353154 R12: dffffc0000000000 [ 86.002163][ T1537] R13: 0000000000000001 R14: ffff8880897ca000 R15: 0000000000000003 [ 86.010277][ T1537] ? vprintk_func+0x97/0x1a6 [ 86.014920][ T1537] ? refcount_warn_saturate+0x169/0x1e0 [ 86.020483][ T1537] l2cap_global_chan_by_psm+0x53f/0x5b0 [ 86.026056][ T1537] ? l2cap_chan_timeout+0x450/0x450 [ 86.031273][ T1537] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 86.037287][ T1537] ? mark_lock+0xbc/0x1710 [ 86.041732][ T1537] ? __lock_acquire+0x16cb/0x5640 [ 86.046787][ T1537] l2cap_recv_frame+0xc3b/0xae10 [ 86.051762][ T1537] ? hci_rx_work+0x35b/0xb50 [ 86.056393][ T1537] ? __lock_acquire+0xbb5/0x5640 [ 86.061361][ T1537] ? l2cap_config_rsp.isra.0+0x1130/0x1130 [ 86.067223][ T1537] ? find_held_lock+0x2d/0x110 [ 86.072007][ T1537] ? hci_rx_work+0x498/0xb50 [ 86.076616][ T1537] ? lock_downgrade+0x830/0x830 [ 86.081488][ T1537] ? lock_acquire+0x1f1/0xad0 [ 86.086273][ T1537] ? hci_rx_work+0x33d/0xb50 [ 86.090896][ T1537] ? find_held_lock+0x2d/0x110 [ 86.095789][ T1537] ? __mutex_unlock_slowpath+0xe2/0x610 [ 86.101443][ T1537] ? hci_conn_enter_active_mode+0x11a/0x2e0 [ 86.107378][ T1537] l2cap_recv_acldata+0x7f6/0x8e0 [ 86.112623][ T1537] hci_rx_work+0x4c7/0xb50 [ 86.117087][ T1537] process_one_work+0x94c/0x1670 [ 86.122063][ T1537] ? lock_release+0x8e0/0x8e0 [ 86.126759][ T1537] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 86.132245][ T1537] ? rwlock_bug.part.0+0x90/0x90 [ 86.137392][ T1537] worker_thread+0x64c/0x1120 [ 86.142096][ T1537] ? process_one_work+0x1670/0x1670 [ 86.147410][ T1537] kthread+0x3b5/0x4a0 [ 86.151490][ T1537] ? __kthread_bind_mask+0xc0/0xc0 [ 86.156608][ T1537] ? __kthread_bind_mask+0xc0/0xc0 [ 86.161745][ T1537] ret_from_fork+0x1f/0x30 [ 86.167338][ T1537] Kernel Offset: disabled [ 86.171733][ T1537] Rebooting in 86400 seconds..