[ 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 '10.128.0.104' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program 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: [ 66.490152][ T23] ================================================================== [ 66.498417][ T23] BUG: KASAN: use-after-free in l2cap_chan_close+0x564/0xb10 [ 66.505816][ T23] Read of size 1 at addr ffff88809d984020 by task kworker/1:1/23 [ 66.513523][ T23] [ 66.515858][ T23] CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 5.8.0-syzkaller #0 [ 66.523658][ T23] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.534701][ T23] Workqueue: events do_enable_set [ 66.539738][ T23] Call Trace: [ 66.543036][ T23] dump_stack+0x18f/0x20d [ 66.547374][ T23] ? l2cap_chan_close+0x564/0xb10 [ 66.552428][ T23] ? l2cap_chan_close+0x564/0xb10 [ 66.557557][ T23] print_address_description.constprop.0.cold+0xae/0x436 [ 66.564611][ T23] ? mark_lock+0xbc/0x1710 [ 66.569034][ T23] ? vprintk_func+0x97/0x1a6 [ 66.573661][ T23] ? l2cap_chan_close+0x564/0xb10 [ 66.578690][ T23] kasan_report.cold+0x1f/0x37 [ 66.583495][ T23] ? l2cap_chan_close+0x564/0xb10 [ 66.588527][ T23] l2cap_chan_close+0x564/0xb10 [ 66.593388][ T23] ? l2cap_retransmit_all+0x760/0x760 [ 66.598764][ T23] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 66.604889][ T23] do_enable_set+0x4ed/0x980 [ 66.609486][ T23] ? chan_recv_cb+0xa10/0xa10 [ 66.614176][ T23] ? _raw_spin_unlock_irq+0x1f/0x80 [ 66.619382][ T23] ? _raw_spin_unlock_irq+0x1f/0x80 [ 66.624591][ T23] ? lock_is_held_type+0xbb/0xf0 [ 66.629548][ T23] process_one_work+0x94c/0x1670 [ 66.634500][ T23] ? lock_release+0x8e0/0x8e0 [ 66.639191][ T23] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 66.644574][ T23] ? rwlock_bug.part.0+0x90/0x90 [ 66.649566][ T23] worker_thread+0x64c/0x1120 [ 66.654283][ T23] ? __kthread_parkme+0x13f/0x1e0 [ 66.659312][ T23] ? process_one_work+0x1670/0x1670 [ 66.664550][ T23] kthread+0x3b5/0x4a0 [ 66.668625][ T23] ? __kthread_bind_mask+0xc0/0xc0 [ 66.673765][ T23] ? __kthread_bind_mask+0xc0/0xc0 [ 66.678885][ T23] ret_from_fork+0x1f/0x30 [ 66.683309][ T23] [ 66.685641][ T23] Allocated by task 23: [ 66.689796][ T23] save_stack+0x1b/0x40 [ 66.693953][ T23] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 66.699586][ T23] kmem_cache_alloc_trace+0x14f/0x2d0 [ 66.704960][ T23] l2cap_chan_create+0x40/0x3a0 [ 66.709824][ T23] do_enable_set+0x52f/0x980 [ 66.714415][ T23] process_one_work+0x94c/0x1670 [ 66.719355][ T23] worker_thread+0x64c/0x1120 [ 66.724034][ T23] kthread+0x3b5/0x4a0 [ 66.728108][ T23] ret_from_fork+0x1f/0x30 [ 66.732514][ T23] [ 66.734842][ T23] Freed by task 2578: [ 66.738826][ T23] save_stack+0x1b/0x40 [ 66.742987][ T23] __kasan_slab_free+0xf5/0x140 [ 66.747838][ T23] kfree+0x103/0x2c0 [ 66.751737][ T23] l2cap_chan_put+0x1b2/0x230 [ 66.756627][ T23] do_enable_set+0x4f9/0x980 [ 66.761220][ T23] process_one_work+0x94c/0x1670 [ 66.766159][ T23] worker_thread+0x64c/0x1120 [ 66.770836][ T23] kthread+0x3b5/0x4a0 [ 66.775028][ T23] ret_from_fork+0x1f/0x30 [ 66.779435][ T23] [ 66.781771][ T23] The buggy address belongs to the object at ffff88809d984000 [ 66.781771][ T23] which belongs to the cache kmalloc-2k of size 2048 [ 66.796090][ T23] The buggy address is located 32 bytes inside of [ 66.796090][ T23] 2048-byte region [ffff88809d984000, ffff88809d984800) [ 66.809382][ T23] The buggy address belongs to the page: [ 66.815020][ T23] page:ffffea0002766100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 66.824126][ T23] flags: 0xfffe0000000200(slab) [ 66.828982][ T23] raw: 00fffe0000000200 ffffea000276f6c8 ffffea0002a20f88 ffff8880aa000e00 [ 66.837576][ T23] raw: 0000000000000000 ffff88809d984000 0000000100000001 0000000000000000 [ 66.846160][ T23] page dumped because: kasan: bad access detected [ 66.852569][ T23] [ 66.854893][ T23] Memory state around the buggy address: [ 66.860531][ T23] ffff88809d983f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 66.868595][ T23] ffff88809d983f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 66.876682][ T23] >ffff88809d984000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 66.884760][ T23] ^ executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 66.889872][ T23] ffff88809d984080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 66.897937][ T23] ffff88809d984100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 66.906016][ T23] ================================================================== [ 66.914074][ T23] 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 [ 67.004936][ T23] Kernel panic - not syncing: panic_on_warn set ... [ 67.011559][ T23] CPU: 1 PID: 23 Comm: kworker/1:1 Tainted: G B 5.8.0-syzkaller #0 [ 67.020738][ T23] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.030794][ T23] Workqueue: events do_enable_set [ 67.035811][ T23] Call Trace: [ 67.039101][ T23] dump_stack+0x18f/0x20d [ 67.043431][ T23] ? l2cap_chan_close+0x560/0xb10 [ 67.048458][ T23] panic+0x2e3/0x75c [ 67.052442][ T23] ? __warn_printk+0xf3/0xf3 [ 67.057033][ T23] ? preempt_schedule_common+0x59/0xc0 [ 67.062523][ T23] ? l2cap_chan_close+0x564/0xb10 [ 67.067550][ T23] ? preempt_schedule_thunk+0x16/0x18 [ 67.072929][ T23] ? trace_hardirqs_on+0x55/0x220 [ 67.077951][ T23] ? l2cap_chan_close+0x564/0xb10 [ 67.082974][ T23] ? l2cap_chan_close+0x564/0xb10 [ 67.088021][ T23] end_report+0x4d/0x53 [ 67.092179][ T23] kasan_report.cold+0xd/0x37 [ 67.096856][ T23] ? l2cap_chan_close+0x564/0xb10 [ 67.101881][ T23] l2cap_chan_close+0x564/0xb10 [ 67.106740][ T23] ? l2cap_retransmit_all+0x760/0x760 [ 67.112135][ T23] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 67.118118][ T23] do_enable_set+0x4ed/0x980 [ 67.122707][ T23] ? chan_recv_cb+0xa10/0xa10 [ 67.127413][ T23] ? _raw_spin_unlock_irq+0x1f/0x80 [ 67.132612][ T23] ? _raw_spin_unlock_irq+0x1f/0x80 [ 67.137807][ T23] ? lock_is_held_type+0xbb/0xf0 [ 67.142748][ T23] process_one_work+0x94c/0x1670 [ 67.147686][ T23] ? lock_release+0x8e0/0x8e0 [ 67.152387][ T23] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 67.157757][ T23] ? rwlock_bug.part.0+0x90/0x90 [ 67.162722][ T23] worker_thread+0x64c/0x1120 [ 67.167401][ T23] ? __kthread_parkme+0x13f/0x1e0 [ 67.172423][ T23] ? process_one_work+0x1670/0x1670 [ 67.177617][ T23] kthread+0x3b5/0x4a0 [ 67.181683][ T23] ? __kthread_bind_mask+0xc0/0xc0 [ 67.186791][ T23] ? __kthread_bind_mask+0xc0/0xc0 [ 67.192039][ T23] ret_from_fork+0x1f/0x30 [ 67.197446][ T23] Kernel Offset: disabled [ 67.201760][ T23] Rebooting in 86400 seconds..