[ OK ] Reached target Login Prompts. [ 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 '10.128.1.34' (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 syzkaller login: [ 59.434971][ T4000] ================================================================== [ 59.443221][ T4000] BUG: KASAN: use-after-free in l2cap_chan_close+0x763/0xb10 [ 59.450608][ T4000] Read of size 1 at addr ffff888093197020 by task kworker/0:6/4000 [ 59.458525][ T4000] [ 59.460861][ T4000] CPU: 0 PID: 4000 Comm: kworker/0:6 Not tainted 5.7.0-rc6-syzkaller #0 [ 59.469279][ T4000] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.479585][ T4000] Workqueue: events do_enable_set executing program executing program executing program [ 59.484610][ T4000] Call Trace: [ 59.487905][ T4000] dump_stack+0x188/0x20d [ 59.492252][ T4000] print_address_description.constprop.0.cold+0xd3/0x413 [ 59.499370][ T4000] ? mark_held_locks+0xe0/0xe0 [ 59.504141][ T4000] ? vprintk_func+0x81/0x17e [ 59.508842][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 59.513958][ T4000] __kasan_report.cold+0x20/0x38 [ 59.518990][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 59.524063][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 59.530135][ T4000] kasan_report+0x33/0x50 executing program executing program executing program [ 59.534474][ T4000] l2cap_chan_close+0x763/0xb10 [ 59.539618][ T4000] ? l2cap_send_i_or_rr_or_rnr+0x320/0x320 [ 59.545538][ T4000] do_enable_set+0x4cf/0x8e0 [ 59.550144][ T4000] ? lowpan_control_write+0x480/0x480 [ 59.555620][ T4000] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 59.561184][ T4000] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 59.567272][ T4000] ? _raw_spin_unlock_irq+0x1f/0x80 [ 59.572571][ T4000] process_one_work+0x965/0x16a0 [ 59.577524][ T4000] ? lock_release+0x800/0x800 executing program executing program executing program [ 59.582224][ T4000] ? pwq_dec_nr_in_flight+0x310/0x310 [ 59.587807][ T4000] ? rwlock_bug.part.0+0x90/0x90 [ 59.592758][ T4000] worker_thread+0x96/0xe20 [ 59.597280][ T4000] ? process_one_work+0x16a0/0x16a0 [ 59.602838][ T4000] kthread+0x388/0x470 [ 59.607031][ T4000] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 59.612759][ T4000] ret_from_fork+0x24/0x30 [ 59.617188][ T4000] [ 59.619606][ T4000] Allocated by task 35: [ 59.623933][ T4000] save_stack+0x1b/0x40 [ 59.629240][ T4000] __kasan_kmalloc.constprop.0+0xbf/0xd0 executing program executing program [ 59.634866][ T4000] kmem_cache_alloc_trace+0x153/0x7d0 [ 59.640232][ T4000] l2cap_chan_create+0x40/0x3a0 [ 59.645080][ T4000] chan_create+0xc/0xd0 [ 59.649232][ T4000] do_enable_set+0x511/0x8e0 [ 59.653827][ T4000] process_one_work+0x965/0x16a0 [ 59.658859][ T4000] worker_thread+0x96/0xe20 [ 59.663358][ T4000] kthread+0x388/0x470 [ 59.667424][ T4000] ret_from_fork+0x24/0x30 [ 59.671828][ T4000] [ 59.674150][ T4000] Freed by task 35: [ 59.677953][ T4000] save_stack+0x1b/0x40 executing program executing program executing program executing program [ 59.682107][ T4000] __kasan_slab_free+0xf7/0x140 [ 59.686951][ T4000] kfree+0x109/0x2b0 [ 59.690842][ T4000] l2cap_chan_put+0x1b2/0x230 [ 59.695516][ T4000] do_enable_set+0x4db/0x8e0 [ 59.700101][ T4000] process_one_work+0x965/0x16a0 [ 59.705033][ T4000] worker_thread+0x96/0xe20 [ 59.709530][ T4000] kthread+0x388/0x470 [ 59.713594][ T4000] ret_from_fork+0x24/0x30 [ 59.718000][ T4000] [ 59.720329][ T4000] The buggy address belongs to the object at ffff888093197000 [ 59.720329][ T4000] which belongs to the cache kmalloc-2k of size 2048 executing program executing program [ 59.734822][ T4000] The buggy address is located 32 bytes inside of [ 59.734822][ T4000] 2048-byte region [ffff888093197000, ffff888093197800) [ 59.748186][ T4000] The buggy address belongs to the page: [ 59.754518][ T4000] page:ffffea00024c65c0 refcount:1 mapcount:0 mapping:00000000c923272b index:0x0 [ 59.763623][ T4000] flags: 0xfffe0000000200(slab) [ 59.768479][ T4000] raw: 00fffe0000000200 ffffea000279b948 ffffea0002a40488 ffff8880aa000e00 [ 59.777157][ T4000] raw: 0000000000000000 ffff888093197000 0000000100000001 0000000000000000 executing program executing program executing program executing program [ 59.785735][ T4000] page dumped because: kasan: bad access detected [ 59.792154][ T4000] [ 59.794484][ T4000] Memory state around the buggy address: [ 59.800111][ T4000] ffff888093196f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 59.808170][ T4000] ffff888093196f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 59.816238][ T4000] >ffff888093197000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 59.824290][ T4000] ^ executing program executing program executing program executing program [ 59.829398][ T4000] ffff888093197080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 59.837469][ T4000] ffff888093197100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 59.845524][ T4000] ================================================================== [ 59.853580][ T4000] Disabling lock debugging due to kernel taint [ 59.910535][ T4000] Kernel panic - not syncing: panic_on_warn set ... [ 59.917759][ T4000] CPU: 0 PID: 4000 Comm: kworker/0:6 Tainted: G B 5.7.0-rc6-syzkaller #0 [ 59.927463][ T4000] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.937521][ T4000] Workqueue: events do_enable_set [ 59.942539][ T4000] Call Trace: [ 59.945825][ T4000] dump_stack+0x188/0x20d [ 59.950153][ T4000] panic+0x2e3/0x75c [ 59.954040][ T4000] ? add_taint.cold+0x16/0x16 [ 59.958709][ T4000] ? preempt_schedule_common+0x5e/0xc0 [ 59.964159][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 59.969247][ T4000] ? preempt_schedule_thunk+0x16/0x18 [ 59.974615][ T4000] ? trace_hardirqs_on+0x55/0x220 [ 59.979633][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 59.984672][ T4000] end_report+0x4d/0x53 [ 59.988824][ T4000] __kasan_report.cold+0xd/0x38 [ 59.993682][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 59.998705][ T4000] ? l2cap_chan_close+0x763/0xb10 [ 60.003981][ T4000] kasan_report+0x33/0x50 [ 60.008302][ T4000] l2cap_chan_close+0x763/0xb10 [ 60.013172][ T4000] ? l2cap_send_i_or_rr_or_rnr+0x320/0x320 [ 60.018985][ T4000] do_enable_set+0x4cf/0x8e0 [ 60.023575][ T4000] ? lowpan_control_write+0x480/0x480 [ 60.028962][ T4000] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 60.034506][ T4000] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 60.040493][ T4000] ? _raw_spin_unlock_irq+0x1f/0x80 [ 60.045863][ T4000] process_one_work+0x965/0x16a0 [ 60.050906][ T4000] ? lock_release+0x800/0x800 [ 60.055603][ T4000] ? pwq_dec_nr_in_flight+0x310/0x310 [ 60.060976][ T4000] ? rwlock_bug.part.0+0x90/0x90 [ 60.065915][ T4000] worker_thread+0x96/0xe20 [ 60.070442][ T4000] ? process_one_work+0x16a0/0x16a0 [ 60.075633][ T4000] kthread+0x388/0x470 [ 60.079698][ T4000] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 60.085414][ T4000] ret_from_fork+0x24/0x30 [ 60.091540][ T4000] Kernel Offset: disabled [ 60.095925][ T4000] Rebooting in 86400 seconds..