[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.112' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 37.902788] audit: type=1400 audit(1596693423.732:8): avc: denied { execmem } for pid=6356 comm="syz-executor173" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 37.981328] ================================================================== [ 37.988856] BUG: KASAN: use-after-free in l2cap_chan_close+0x4fb/0x770 [ 37.995523] Read of size 1 at addr ffff8880975c3520 by task kworker/0:2/3347 [ 38.002701] [ 38.004328] CPU: 0 PID: 3347 Comm: kworker/0:2 Not tainted 4.14.192-syzkaller #0 [ 38.011851] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.021210] Workqueue: events do_enable_set [ 38.025571] Call Trace: [ 38.028149] dump_stack+0x1b2/0x283 executing program executing program executing program executing program executing program executing program executing program [ 38.031772] print_address_description.cold+0x54/0x1d3 [ 38.037042] kasan_report_error.cold+0x8a/0x194 [ 38.041708] ? l2cap_chan_close+0x4fb/0x770 [ 38.046031] __asan_report_load1_noabort+0x68/0x70 [ 38.050943] ? l2cap_chan_close+0x4fb/0x770 [ 38.055257] l2cap_chan_close+0x4fb/0x770 [ 38.059406] ? __set_monitor_timer+0x110/0x110 [ 38.063977] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 38.069064] do_enable_set+0x473/0x8a0 [ 38.072934] ? lock_acquire+0x170/0x3f0 [ 38.076895] ? chan_recv_cb+0x970/0x970 executing program executing program executing program executing program executing program executing program executing program executing program [ 38.080866] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 38.086311] process_one_work+0x793/0x14a0 [ 38.090537] ? work_busy+0x320/0x320 [ 38.094246] ? worker_thread+0x158/0xff0 [ 38.098305] ? _raw_spin_unlock_irq+0x24/0x80 [ 38.102855] worker_thread+0x5cc/0xff0 [ 38.106738] ? rescuer_thread+0xc80/0xc80 [ 38.110879] kthread+0x30d/0x420 [ 38.114243] ? kthread_create_on_node+0xd0/0xd0 [ 38.118915] ret_from_fork+0x24/0x30 [ 38.122619] [ 38.124223] Allocated by task 4408: [ 38.127838] kasan_kmalloc+0xeb/0x160 executing program executing program executing program executing program executing program executing program executing program [ 38.131729] kmem_cache_alloc_trace+0x131/0x3d0 [ 38.136521] l2cap_chan_create+0x3e/0x3c0 [ 38.140755] do_enable_set+0x4ac/0x8a0 [ 38.144703] process_one_work+0x793/0x14a0 [ 38.148916] worker_thread+0x5cc/0xff0 [ 38.152791] kthread+0x30d/0x420 [ 38.156152] ret_from_fork+0x24/0x30 [ 38.159846] [ 38.161554] Freed by task 4408: [ 38.164821] kasan_slab_free+0xc3/0x1a0 [ 38.168787] kfree+0xc9/0x250 [ 38.171886] l2cap_chan_put+0x152/0x1b0 [ 38.175880] do_enable_set+0x47f/0x8a0 executing program executing program executing program executing program executing program executing program executing program executing program [ 38.179765] process_one_work+0x793/0x14a0 [ 38.183996] worker_thread+0x5cc/0xff0 [ 38.187883] kthread+0x30d/0x420 [ 38.191325] ret_from_fork+0x24/0x30 [ 38.195016] [ 38.196644] The buggy address belongs to the object at ffff8880975c3500 [ 38.196644] which belongs to the cache kmalloc-2048 of size 2048 [ 38.209464] The buggy address is located 32 bytes inside of [ 38.209464] 2048-byte region [ffff8880975c3500, ffff8880975c3d00) [ 38.221321] The buggy address belongs to the page: executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.226242] page:ffffea00025d7080 count:1 mapcount:0 mapping:ffff8880975c2400 index:0x0 compound_mapcount: 0 [ 38.236719] flags: 0xfffe0000008100(slab|head) [ 38.241300] raw: 00fffe0000008100 ffff8880975c2400 0000000000000000 0000000100000003 [ 38.249171] raw: ffffea00025f1620 ffffea00025e4b20 ffff88812fe52c40 0000000000000000 [ 38.257072] page dumped because: kasan: bad access detected [ 38.262769] [ 38.264372] Memory state around the buggy address: [ 38.269283] ffff8880975c3400: 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 [ 38.276637] ffff8880975c3480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 38.284010] >ffff8880975c3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.291351] ^ [ 38.295756] ffff8880975c3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.303112] ffff8880975c3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 38.310475] ================================================================== [ 38.322073] 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 [ 38.333816] Kernel panic - not syncing: panic_on_warn set ... [ 38.333816] [ 38.341202] CPU: 0 PID: 3347 Comm: kworker/0:2 Tainted: G B 4.14.192-syzkaller #0 [ 38.349938] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.359295] Workqueue: events do_enable_set [ 38.363611] Call Trace: [ 38.366194] dump_stack+0x1b2/0x283 [ 38.369819] panic+0x1f9/0x42d [ 38.373051] ? add_taint.cold+0x16/0x16 [ 38.377051] ? ___preempt_schedule+0x16/0x18 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.381458] kasan_end_report+0x43/0x49 [ 38.385441] kasan_report_error.cold+0xa7/0x194 [ 38.392279] ? l2cap_chan_close+0x4fb/0x770 [ 38.396597] __asan_report_load1_noabort+0x68/0x70 [ 38.401527] ? l2cap_chan_close+0x4fb/0x770 [ 38.405847] l2cap_chan_close+0x4fb/0x770 [ 38.409994] ? __set_monitor_timer+0x110/0x110 [ 38.414574] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 38.419671] do_enable_set+0x473/0x8a0 [ 38.425291] ? lock_acquire+0x170/0x3f0 [ 38.429609] ? chan_recv_cb+0x970/0x970 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 38.433666] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 38.439114] process_one_work+0x793/0x14a0 [ 38.443354] ? work_busy+0x320/0x320 [ 38.447074] ? worker_thread+0x158/0xff0 [ 38.451145] ? _raw_spin_unlock_irq+0x24/0x80 [ 38.455730] worker_thread+0x5cc/0xff0 [ 38.459659] ? rescuer_thread+0xc80/0xc80 [ 38.463801] kthread+0x30d/0x420 [ 38.467160] ? kthread_create_on_node+0xd0/0xd0 [ 38.471824] ret_from_fork+0x24/0x30 [ 38.476964] Kernel Offset: disabled [ 38.480591] Rebooting in 86400 seconds..