[ 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 '10.128.0.46' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 47.285347] audit: type=1400 audit(1596913669.871:8): avc: denied { execmem } for pid=6358 comm="syz-executor973" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 47.311075] ================================================================== [ 47.318567] BUG: KASAN: use-after-free in l2cap_chan_close+0x4fb/0x770 [ 47.325232] Read of size 1 at addr ffff8880976a24e0 by task kworker/1:2/3653 [ 47.332406] executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.334043] CPU: 1 PID: 3653 Comm: kworker/1:2 Not tainted 4.14.193-syzkaller #0 [ 47.341575] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.350934] Workqueue: events do_enable_set [ 47.355254] Call Trace: [ 47.357856] dump_stack+0x1b2/0x283 [ 47.361574] print_address_description.cold+0x54/0x1d3 [ 47.366852] kasan_report_error.cold+0x8a/0x194 [ 47.371522] ? l2cap_chan_close+0x4fb/0x770 [ 47.375843] __asan_report_load1_noabort+0x68/0x70 [ 47.380770] ? l2cap_chan_close+0x4fb/0x770 [ 47.385094] l2cap_chan_close+0x4fb/0x770 [ 47.389533] ? __set_monitor_timer+0x110/0x110 [ 47.394129] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 47.399240] do_enable_set+0x473/0x8a0 [ 47.403227] ? lock_acquire+0x170/0x3f0 [ 47.407210] ? chan_recv_cb+0x970/0x970 [ 47.411185] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 47.416637] process_one_work+0x793/0x14a0 [ 47.420882] ? work_busy+0x320/0x320 [ 47.424616] ? worker_thread+0x158/0xff0 [ 47.428764] ? _raw_spin_unlock_irq+0x24/0x80 [ 47.433253] worker_thread+0x5cc/0xff0 [ 47.437136] ? rescuer_thread+0xc80/0xc80 [ 47.441270] kthread+0x30d/0x420 [ 47.444639] ? kthread_create_on_node+0xd0/0xd0 [ 47.449307] ret_from_fork+0x24/0x30 [ 47.453016] [ 47.454642] Allocated by task 24: [ 47.458095] kasan_kmalloc+0xeb/0x160 [ 47.461879] kmem_cache_alloc_trace+0x131/0x3d0 [ 47.466532] l2cap_chan_create+0x3e/0x3c0 [ 47.470671] do_enable_set+0x4ac/0x8a0 [ 47.474553] process_one_work+0x793/0x14a0 [ 47.478785] worker_thread+0x5cc/0xff0 [ 47.482655] kthread+0x30d/0x420 [ 47.486007] ret_from_fork+0x24/0x30 [ 47.489709] [ 47.491325] Freed by task 24: [ 47.494422] kasan_slab_free+0xc3/0x1a0 [ 47.498376] kfree+0xc9/0x250 [ 47.501467] l2cap_chan_put+0x152/0x1b0 [ 47.505428] do_enable_set+0x47f/0x8a0 [ 47.509299] process_one_work+0x793/0x14a0 [ 47.513518] worker_thread+0x5cc/0xff0 [ 47.517430] kthread+0x30d/0x420 [ 47.520780] ret_from_fork+0x24/0x30 [ 47.524472] [ 47.526083] The buggy address belongs to the object at ffff8880976a24c0 [ 47.526083] which belongs to the cache kmalloc-2048 of size 2048 [ 47.538904] The buggy address is located 32 bytes inside of [ 47.538904] 2048-byte region [ffff8880976a24c0, ffff8880976a2cc0) [ 47.550768] The buggy address belongs to the page: [ 47.555700] page:ffffea00025da880 count:1 mapcount:0 mapping:ffff8880976a24c0 index:0x0 compound_mapcount: 0 [ 47.565679] flags: 0xfffe0000008100(slab|head) [ 47.570262] raw: 00fffe0000008100 ffff8880976a24c0 0000000000000000 0000000100000003 [ 47.578146] raw: ffffea00025d3ca0 ffffea00025c0720 ffff88812fe52c40 0000000000000000 [ 47.586008] page dumped because: kasan: bad access detected [ 47.591701] [ 47.593313] Memory state around the buggy address: [ 47.598311] ffff8880976a2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 47.606723] ffff8880976a2400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 47.614071] >ffff8880976a2480: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 47.621429] ^ [ 47.627910] ffff8880976a2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.635533] ffff8880976a2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.642876] ================================================================== [ 47.650244] Disabling lock debugging due to kernel taint executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.796255] Kernel panic - not syncing: panic_on_warn set ... [ 47.796255] [ 47.803656] CPU: 1 PID: 3653 Comm: kworker/1:2 Tainted: G B 4.14.193-syzkaller #0 [ 47.812401] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.821764] Workqueue: events do_enable_set [ 47.826067] Call Trace: [ 47.828650] dump_stack+0x1b2/0x283 [ 47.832368] panic+0x1f9/0x42d [ 47.835561] ? add_taint.cold+0x16/0x16 [ 47.839520] ? ___preempt_schedule+0x16/0x18 [ 47.843919] kasan_end_report+0x43/0x49 [ 47.847894] kasan_report_error.cold+0xa7/0x194 [ 47.852548] ? l2cap_chan_close+0x4fb/0x770 [ 47.856854] __asan_report_load1_noabort+0x68/0x70 [ 47.861781] ? l2cap_chan_close+0x4fb/0x770 [ 47.866087] l2cap_chan_close+0x4fb/0x770 [ 47.870225] ? __set_monitor_timer+0x110/0x110 [ 47.874810] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 47.879920] do_enable_set+0x473/0x8a0 [ 47.883797] ? lock_acquire+0x170/0x3f0 [ 47.887754] ? chan_recv_cb+0x970/0x970 [ 47.891710] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 47.897235] process_one_work+0x793/0x14a0 [ 47.901455] ? work_busy+0x320/0x320 [ 47.905160] ? worker_thread+0x158/0xff0 [ 47.909204] ? _raw_spin_unlock_irq+0x24/0x80 [ 47.913833] worker_thread+0x5cc/0xff0 [ 47.917708] ? rescuer_thread+0xc80/0xc80 [ 47.921870] kthread+0x30d/0x420 [ 47.925231] ? kthread_create_on_node+0xd0/0xd0 [ 47.929892] ret_from_fork+0x24/0x30 [ 47.934654] Kernel Offset: disabled [ 47.938264] Rebooting in 86400 seconds..