[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.9' (ECDSA) to the list of known hosts. syzkaller login: [ 121.305182] IPVS: ftp: loaded support on port[0] = 21 executing program [ 123.359039] Bluetooth: hci0: command 0x0409 tx timeout [ 125.438888] Bluetooth: hci0: command 0x041b tx timeout executing program [ 127.518660] Bluetooth: hci0: command 0x040f tx timeout [ 129.598656] Bluetooth: hci0: command 0x0419 tx timeout executing program [ 131.678669] Bluetooth: hci0: command 0x0405 tx timeout executing program executing program executing program executing program executing program executing program [ 161.999223] ================================================================== [ 162.006630] BUG: KASAN: use-after-free in __lock_acquire+0x2cb4/0x3ff0 [ 162.013274] Read of size 8 at addr ffff8880b2c64c60 by task kworker/0:2/3634 [ 162.020451] [ 162.022097] CPU: 0 PID: 3634 Comm: kworker/0:2 Not tainted 4.19.172-syzkaller #0 [ 162.029613] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 162.038950] Workqueue: events l2cap_chan_timeout [ 162.043682] Call Trace: [ 162.046253] dump_stack+0x1fc/0x2ef [ 162.049878] print_address_description.cold+0x54/0x219 [ 162.055174] kasan_report_error.cold+0x8a/0x1b9 [ 162.059827] ? __lock_acquire+0x2cb4/0x3ff0 [ 162.064153] __asan_report_load8_noabort+0x88/0x90 [ 162.069091] ? __lock_acquire+0x2cb4/0x3ff0 [ 162.073395] __lock_acquire+0x2cb4/0x3ff0 [ 162.077544] ? trace_hardirqs_off+0x64/0x200 [ 162.081935] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 162.087032] ? debug_object_assert_init+0x242/0x2e0 [ 162.092047] ? mark_held_locks+0xf0/0xf0 [ 162.096110] ? debug_object_free+0x380/0x380 [ 162.100519] ? mark_held_locks+0xf0/0xf0 [ 162.104580] ? __save_stack_trace+0x9f/0x190 [ 162.108986] ? del_timer+0xc3/0x100 [ 162.112598] lock_acquire+0x170/0x3c0 [ 162.116415] ? lock_sock_nested+0x3b/0x110 [ 162.120655] _raw_spin_lock_bh+0x2f/0x40 [ 162.124885] ? lock_sock_nested+0x3b/0x110 [ 162.129126] lock_sock_nested+0x3b/0x110 [ 162.133352] l2cap_sock_teardown_cb+0xa0/0x6d0 [ 162.137928] ? lock_downgrade+0x720/0x720 [ 162.142161] l2cap_chan_del+0xbc/0xa50 [ 162.146088] ? trace_hardirqs_off+0x64/0x200 [ 162.150489] l2cap_chan_close+0x1b5/0x950 [ 162.154623] ? __set_monitor_timer+0x200/0x200 [ 162.159195] ? check_preemption_disabled+0x41/0x280 [ 162.164192] l2cap_chan_timeout+0x17e/0x2f0 [ 162.168548] process_one_work+0x864/0x1570 [ 162.172794] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 162.177461] worker_thread+0x64c/0x1130 [ 162.181424] ? __kthread_parkme+0x133/0x1e0 [ 162.185733] ? process_one_work+0x1570/0x1570 [ 162.190226] kthread+0x33f/0x460 [ 162.193585] ? kthread_park+0x180/0x180 [ 162.197629] ret_from_fork+0x24/0x30 [ 162.201354] [ 162.202983] Allocated by task 8133: [ 162.206590] __kmalloc+0x15a/0x3c0 [ 162.210172] sk_prot_alloc+0x1e2/0x2d0 [ 162.214054] sk_alloc+0x36/0xec0 [ 162.217413] l2cap_sock_alloc.constprop.0+0x31/0x210 [ 162.222523] l2cap_sock_create+0x123/0x1f0 [ 162.226753] bt_sock_create+0x154/0x2a0 [ 162.230719] __sock_create+0x3d8/0x740 [ 162.234603] __sys_socket+0xef/0x200 [ 162.238302] __x64_sys_socket+0x6f/0xb0 [ 162.242259] do_syscall_64+0xf9/0x620 [ 162.246042] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 162.251219] [ 162.252844] Freed by task 8133: [ 162.256280] kfree+0xcc/0x210 [ 162.259394] __sk_destruct+0x684/0x8a0 [ 162.263263] __sk_free+0x165/0x3b0 [ 162.266796] sk_free+0x3b/0x50 [ 162.269988] l2cap_sock_kill.part.0+0x124/0x150 [ 162.274640] l2cap_sock_release+0x1e6/0x290 [ 162.278948] __sock_release+0xcd/0x2a0 [ 162.282834] sock_close+0x15/0x20 [ 162.286280] __fput+0x2ce/0x890 [ 162.289563] task_work_run+0x148/0x1c0 [ 162.293450] do_exit+0xbf3/0x2be0 [ 162.296899] do_group_exit+0x125/0x310 [ 162.300780] get_signal+0x3f2/0x1f70 [ 162.304492] do_signal+0x8f/0x1670 [ 162.308021] exit_to_usermode_loop+0x204/0x2a0 [ 162.312590] do_syscall_64+0x538/0x620 [ 162.316463] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 162.321643] [ 162.323273] The buggy address belongs to the object at ffff8880b2c64bc0 [ 162.323273] which belongs to the cache kmalloc-2048 of size 2048 [ 162.336087] The buggy address is located 160 bytes inside of [ 162.336087] 2048-byte region [ffff8880b2c64bc0, ffff8880b2c653c0) [ 162.348029] The buggy address belongs to the page: [ 162.352940] page:ffffea0002cb1900 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0x0 compound_mapcount: 0 [ 162.362908] flags: 0xfff00000008100(slab|head) [ 162.367579] raw: 00fff00000008100 ffffea0002c00b88 ffffea0002c4cc88 ffff88813bff0c40 [ 162.375443] raw: 0000000000000000 ffff8880b2c64340 0000000100000003 0000000000000000 [ 162.383298] page dumped because: kasan: bad access detected [ 162.389002] [ 162.390611] Memory state around the buggy address: [ 162.395540] ffff8880b2c64b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 162.402884] ffff8880b2c64b80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 162.410230] >ffff8880b2c64c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 162.417587] ^ [ 162.424073] ffff8880b2c64c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 162.431524] ffff8880b2c64d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 162.438864] ================================================================== [ 162.446393] Disabling lock debugging due to kernel taint [ 162.451912] Kernel panic - not syncing: panic_on_warn set ... [ 162.451912] [ 162.459269] CPU: 0 PID: 3634 Comm: kworker/0:2 Tainted: G B 4.19.172-syzkaller #0 [ 162.468342] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 162.477687] Workqueue: events l2cap_chan_timeout [ 162.482419] Call Trace: [ 162.485000] dump_stack+0x1fc/0x2ef [ 162.488621] panic+0x26a/0x50e [ 162.491800] ? __warn_printk+0xf3/0xf3 [ 162.496195] ? lock_downgrade+0x720/0x720 [ 162.500333] ? print_shadow_for_address+0xb8/0x114 [ 162.505247] ? trace_hardirqs_off+0x64/0x200 [ 162.509643] kasan_end_report+0x43/0x49 [ 162.513608] kasan_report_error.cold+0xa7/0x1b9 [ 162.518262] ? __lock_acquire+0x2cb4/0x3ff0 [ 162.522585] __asan_report_load8_noabort+0x88/0x90 [ 162.527497] ? __lock_acquire+0x2cb4/0x3ff0 [ 162.531806] __lock_acquire+0x2cb4/0x3ff0 [ 162.535951] ? trace_hardirqs_off+0x64/0x200 [ 162.540345] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 162.545452] ? debug_object_assert_init+0x242/0x2e0 [ 162.550453] ? mark_held_locks+0xf0/0xf0 [ 162.554499] ? debug_object_free+0x380/0x380 [ 162.558896] ? mark_held_locks+0xf0/0xf0 [ 162.562992] ? __save_stack_trace+0x9f/0x190 [ 162.567391] ? del_timer+0xc3/0x100 [ 162.571176] lock_acquire+0x170/0x3c0 [ 162.574967] ? lock_sock_nested+0x3b/0x110 [ 162.579202] _raw_spin_lock_bh+0x2f/0x40 [ 162.583274] ? lock_sock_nested+0x3b/0x110 [ 162.587495] lock_sock_nested+0x3b/0x110 [ 162.591548] l2cap_sock_teardown_cb+0xa0/0x6d0 [ 162.596135] ? lock_downgrade+0x720/0x720 [ 162.600277] l2cap_chan_del+0xbc/0xa50 [ 162.604185] ? trace_hardirqs_off+0x64/0x200 [ 162.608591] l2cap_chan_close+0x1b5/0x950 [ 162.612734] ? __set_monitor_timer+0x200/0x200 [ 162.617302] ? check_preemption_disabled+0x41/0x280 [ 162.622316] l2cap_chan_timeout+0x17e/0x2f0 [ 162.626638] process_one_work+0x864/0x1570 [ 162.630880] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 162.635537] worker_thread+0x64c/0x1130 [ 162.639499] ? __kthread_parkme+0x133/0x1e0 [ 162.643812] ? process_one_work+0x1570/0x1570 [ 162.648296] kthread+0x33f/0x460 [ 162.651642] ? kthread_park+0x180/0x180 [ 162.655600] ret_from_fork+0x24/0x30 [ 162.659889] Kernel Offset: disabled [ 162.663611] Rebooting in 86400 seconds..