[ OK ] Started OpenBSD Secure Shell server. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.205' (ECDSA) to the list of known hosts. syzkaller login: [ 38.943083] audit: type=1400 audit(1596599580.443:8): avc: denied { execmem } for pid=6439 comm="syz-executor537" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 38.956705] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program [ 40.098154] Bluetooth: Wrong link type (-22) [ 40.109294] Bluetooth: Wrong link type (-22) [ 40.119192] Bluetooth: Wrong link type (-22) [ 40.134769] Bluetooth: Wrong link type (-22) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 40.144587] Bluetooth: Wrong link type (-22) executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 40.185860] Bluetooth: Wrong link type (-22) [ 40.190453] Bluetooth: Wrong link type (-22) [ 40.194993] Bluetooth: Wrong link type (-22) [ 40.200102] Bluetooth: Wrong link type (-22) [ 40.204645] Bluetooth: Wrong link type (-22) [ 40.209243] Bluetooth: Wrong link type (-22) [ 40.213766] Bluetooth: Wrong link type (-22) [ 40.218635] Bluetooth: Wrong link type (-22) [ 40.223172] Bluetooth: Wrong link type (-22) [ 40.227764] Bluetooth: Wrong link type (-22) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 40.232279] Bluetooth: Wrong link type (-22) [ 40.237165] Bluetooth: Wrong link type (-22) [ 40.241688] Bluetooth: Wrong link type (-22) [ 40.246267] Bluetooth: Wrong link type (-22) [ 40.250794] Bluetooth: Wrong link type (-22) [ 40.255321] Bluetooth: Wrong link type (-22) [ 40.260127] Bluetooth: Wrong link type (-22) [ 40.264652] Bluetooth: Wrong link type (-22) [ 40.269235] Bluetooth: Wrong link type (-22) [ 40.273752] Bluetooth: Wrong link type (-22) [ 40.316674] ================================================================== [ 40.324292] BUG: KASAN: use-after-free in hci_send_acl+0xad6/0xc70 [ 40.330595] Read of size 8 at addr ffff8880996b6498 by task kworker/u5:1/6463 [ 40.337846] [ 40.339458] CPU: 0 PID: 6463 Comm: kworker/u5:1 Not tainted 4.19.136-syzkaller #0 [ 40.347056] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.356401] Workqueue: hci0 hci_rx_work [ 40.360360] Call Trace: [ 40.362930] dump_stack+0x1fc/0x2fe [ 40.366543] print_address_description.cold+0x54/0x219 [ 40.371818] kasan_report_error.cold+0x8a/0x1c7 [ 40.376471] ? hci_send_acl+0xad6/0xc70 [ 40.380425] __asan_report_load8_noabort+0x88/0x90 [ 40.385337] ? hci_send_acl+0xad6/0xc70 [ 40.389292] hci_send_acl+0xad6/0xc70 [ 40.393071] ? memcpy+0x35/0x50 [ 40.396331] ? l2cap_build_cmd+0x53e/0x6e0 [ 40.400548] l2cap_send_cmd+0x1bd/0x210 [ 40.404505] l2cap_recv_frame+0x1e75/0xa550 [ 40.408818] ? mark_held_locks+0xf0/0xf0 [ 40.412862] ? kfree_skbmem+0xc1/0x140 [ 40.416728] ? hci_event_packet+0x561/0x858f [ 40.421119] ? l2cap_ertm_init+0xa60/0xa60 [ 40.425338] ? __lock_acquire+0x6de/0x3ff0 [ 40.429556] ? lock_acquire+0x170/0x3c0 [ 40.433513] ? hci_rx_work+0x2e4/0xa90 [ 40.437387] ? hci_rx_work+0x426/0xa90 [ 40.441258] ? lock_downgrade+0x720/0x720 [ 40.445387] ? hci_rx_work+0x2e4/0xa90 [ 40.449255] ? __mutex_add_waiter+0x160/0x160 [ 40.453738] ? __mutex_unlock_slowpath+0xea/0x610 [ 40.458574] ? hci_conn_enter_active_mode+0x19c/0x2c0 [ 40.463762] l2cap_recv_acldata+0x80e/0x910 [ 40.468077] hci_rx_work+0x455/0xa90 [ 40.471793] process_one_work+0x864/0x1570 [ 40.476029] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 40.480688] worker_thread+0x64c/0x1130 [ 40.484652] ? process_one_work+0x1570/0x1570 [ 40.489135] kthread+0x30b/0x410 [ 40.492486] ? kthread_park+0x180/0x180 [ 40.496449] ret_from_fork+0x24/0x30 [ 40.500149] [ 40.501757] Allocated by task 1225: [ 40.505368] kmem_cache_alloc_trace+0x12f/0x380 [ 40.510021] hci_chan_create+0x8e/0x310 [ 40.513988] l2cap_conn_add.part.0+0x18/0xc40 [ 40.518463] l2cap_connect_cfm+0x236/0xe70 [ 40.522675] hci_event_packet+0x3a31/0x858f [ 40.526979] hci_rx_work+0x46b/0xa90 [ 40.530770] process_one_work+0x864/0x1570 [ 40.534981] worker_thread+0x64c/0x1130 [ 40.538935] kthread+0x30b/0x410 [ 40.542279] ret_from_fork+0x24/0x30 [ 40.545965] [ 40.547569] Freed by task 6463: [ 40.550831] kfree+0xcc/0x210 [ 40.553913] hci_event_packet+0xf52/0x858f [ 40.558129] hci_rx_work+0x46b/0xa90 [ 40.561819] process_one_work+0x864/0x1570 [ 40.566038] worker_thread+0x64c/0x1130 [ 40.569989] kthread+0x30b/0x410 [ 40.573336] ret_from_fork+0x24/0x30 [ 40.577021] [ 40.578629] The buggy address belongs to the object at ffff8880996b6480 [ 40.578629] which belongs to the cache kmalloc-128 of size 128 [ 40.591289] The buggy address is located 24 bytes inside of [ 40.591289] 128-byte region [ffff8880996b6480, ffff8880996b6500) [ 40.603054] The buggy address belongs to the page: [ 40.607963] page:ffffea000265ad80 count:1 mapcount:0 mapping:ffff88812c39c640 index:0x0 [ 40.616086] flags: 0xfffe0000000100(slab) [ 40.620228] raw: 00fffe0000000100 ffffea0002a18fc8 ffff88812c394548 ffff88812c39c640 [ 40.628097] raw: 0000000000000000 ffff8880996b6000 0000000100000015 0000000000000000 [ 40.636059] page dumped because: kasan: bad access detected [ 40.641753] [ 40.643374] Memory state around the buggy address: [ 40.648291] ffff8880996b6380: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 40.655633] ffff8880996b6400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc executing program [ 40.662988] >ffff8880996b6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.670326] ^ [ 40.674455] ffff8880996b6500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 40.681797] ffff8880996b6580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 40.689133] ================================================================== [ 40.696467] Disabling lock debugging due to kernel taint [ 40.704521] Kernel panic - not syncing: panic_on_warn set ... [ 40.704521] [ 40.711907] CPU: 1 PID: 6463 Comm: kworker/u5:1 Tainted: G B 4.19.136-syzkaller #0 [ 40.720910] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.730274] Workqueue: hci0 hci_rx_work [ 40.734236] Call Trace: [ 40.736805] dump_stack+0x1fc/0x2fe [ 40.740407] panic+0x26a/0x50e [ 40.743574] ? __warn_printk+0xf3/0xf3 [ 40.747440] ? preempt_schedule_common+0x45/0xc0 [ 40.752171] ? ___preempt_schedule+0x16/0x18 [ 40.756556] ? trace_hardirqs_on+0x55/0x210 [ 40.760856] kasan_end_report+0x43/0x49 [ 40.764804] kasan_report_error.cold+0xa7/0x1c7 [ 40.769450] ? hci_send_acl+0xad6/0xc70 [ 40.773397] __asan_report_load8_noabort+0x88/0x90 [ 40.778349] ? hci_send_acl+0xad6/0xc70 [ 40.782299] hci_send_acl+0xad6/0xc70 [ 40.786098] ? memcpy+0x35/0x50 [ 40.789355] ? l2cap_build_cmd+0x53e/0x6e0 [ 40.793566] l2cap_send_cmd+0x1bd/0x210 [ 40.797519] l2cap_recv_frame+0x1e75/0xa550 [ 40.801819] ? mark_held_locks+0xf0/0xf0 [ 40.805857] ? kfree_skbmem+0xc1/0x140 [ 40.809733] ? hci_event_packet+0x561/0x858f [ 40.814126] ? l2cap_ertm_init+0xa60/0xa60 [ 40.818349] ? __lock_acquire+0x6de/0x3ff0 [ 40.822568] ? lock_acquire+0x170/0x3c0 [ 40.826520] ? hci_rx_work+0x2e4/0xa90 [ 40.830386] ? hci_rx_work+0x426/0xa90 [ 40.834264] ? lock_downgrade+0x720/0x720 [ 40.838389] ? hci_rx_work+0x2e4/0xa90 [ 40.842253] ? __mutex_add_waiter+0x160/0x160 [ 40.846727] ? __mutex_unlock_slowpath+0xea/0x610 [ 40.851545] ? hci_conn_enter_active_mode+0x19c/0x2c0 [ 40.856750] l2cap_recv_acldata+0x80e/0x910 [ 40.861051] hci_rx_work+0x455/0xa90 [ 40.864740] process_one_work+0x864/0x1570 [ 40.868954] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 40.873600] worker_thread+0x64c/0x1130 [ 40.877554] ? process_one_work+0x1570/0x1570 [ 40.886036] kthread+0x30b/0x410 [ 40.889400] ? kthread_park+0x180/0x180 [ 40.893360] ret_from_fork+0x24/0x30 [ 40.898277] Kernel Offset: disabled [ 40.901893] Rebooting in 86400 seconds..