[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.70' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program 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: [ 175.071762] ================================================================== [ 175.079445] BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 [ 175.086092] Read of size 8 at addr ffff8880a3011620 by task kworker/u4:0/5 [ 175.093601] [ 175.095216] CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.218-syzkaller #0 [ 175.102564] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 175.111944] Workqueue: tipc_rcv tipc_recv_work [ 175.116542] Call Trace: [ 175.119124] dump_stack+0x1b2/0x281 [ 175.122731] print_address_description.cold+0x54/0x1d3 [ 175.128075] kasan_report_error.cold+0x8a/0x191 [ 175.132728] ? __lock_acquire+0x2c57/0x3f20 [ 175.137057] __asan_report_load8_noabort+0x68/0x70 [ 175.141977] ? tipc_subscrb_rcv_cb+0x2c0/0xa40 [ 175.146537] ? __lock_acquire+0x2c57/0x3f20 [ 175.150859] __lock_acquire+0x2c57/0x3f20 [ 175.155278] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 175.160294] ? _raw_spin_unlock_irq+0x5a/0x80 [ 175.164784] ? finish_task_switch+0x178/0x610 [ 175.169520] ? finish_task_switch+0x14d/0x610 [ 175.174013] ? trace_hardirqs_on+0x10/0x10 [ 175.178238] ? trace_hardirqs_on+0x10/0x10 [ 175.182456] ? rcu_read_unlock_special+0x776/0xdd0 [ 175.187379] ? mark_held_locks+0xa6/0xf0 [ 175.191431] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 175.196515] lock_acquire+0x170/0x3f0 [ 175.200312] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 175.204876] _raw_spin_lock_bh+0x2f/0x40 [ 175.208935] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 175.213597] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 175.218003] tipc_receive_from_sock+0x25c/0x450 [ 175.222660] ? trace_hardirqs_on+0x10/0x10 [ 175.227328] ? lock_acquire+0x170/0x3f0 [ 175.231281] ? tipc_close_conn+0x200/0x200 [ 175.235491] tipc_recv_work+0x75/0xd0 [ 175.239286] process_one_work+0x793/0x14a0 [ 175.243556] ? work_busy+0x320/0x320 [ 175.247254] ? worker_thread+0x158/0xff0 [ 175.251293] ? _raw_spin_unlock_irq+0x24/0x80 [ 175.255763] worker_thread+0x5cc/0xff0 [ 175.259626] ? rescuer_thread+0xc80/0xc80 [ 175.263747] kthread+0x30d/0x420 [ 175.267087] ? kthread_create_on_node+0xd0/0xd0 [ 175.271747] ret_from_fork+0x24/0x30 [ 175.275437] [ 175.277038] Allocated by task 2932: [ 175.280674] kasan_kmalloc+0xeb/0x160 [ 175.284548] kmem_cache_alloc_trace+0x131/0x3d0 [ 175.289208] tipc_subscrb_connect_cb+0x40/0x150 [ 175.293850] tipc_accept_from_sock+0x25b/0x400 [ 175.298418] tipc_recv_work+0x75/0xd0 [ 175.302209] process_one_work+0x793/0x14a0 [ 175.306431] worker_thread+0x5cc/0xff0 [ 175.310293] kthread+0x30d/0x420 [ 175.313764] ret_from_fork+0x24/0x30 [ 175.317552] [ 175.319156] Freed by task 22: [ 175.322240] kasan_slab_free+0xc3/0x1a0 [ 175.326204] kfree+0xc9/0x250 [ 175.329288] tipc_subscrb_put+0x22/0x30 [ 175.333250] tipc_close_conn+0x16a/0x200 [ 175.337298] tipc_send_work+0x41e/0x520 [ 175.341249] process_one_work+0x793/0x14a0 [ 175.345470] worker_thread+0x5cc/0xff0 [ 175.349333] kthread+0x30d/0x420 [ 175.352677] ret_from_fork+0x24/0x30 [ 175.356361] [ 175.357964] The buggy address belongs to the object at ffff8880a3011600 [ 175.357964] which belongs to the cache kmalloc-96 of size 96 [ 175.370427] The buggy address is located 32 bytes inside of [ 175.370427] 96-byte region [ffff8880a3011600, ffff8880a3011660) [ 175.382205] The buggy address belongs to the page: [ 175.387112] page:ffffea00028c0440 count:1 mapcount:0 mapping:ffff8880a3011000 index:0x0 [ 175.395232] flags: 0xfff00000000100(slab) [ 175.399396] raw: 00fff00000000100 ffff8880a3011000 0000000000000000 0000000100000020 [ 175.407283] raw: ffffea0002863ea0 ffffea000284bd20 ffff88813fe804c0 0000000000000000 [ 175.415171] page dumped because: kasan: bad access detected [ 175.420912] [ 175.422514] Memory state around the buggy address: [ 175.427909] ffff8880a3011500: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 175.435261] ffff8880a3011580: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 175.442610] >ffff8880a3011600: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 175.450132] ^ [ 175.454667] ffff8880a3011680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 175.462005] ffff8880a3011700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 175.469341] ================================================================== [ 175.477041] Disabling lock debugging due to kernel taint [ 175.482554] Kernel panic - not syncing: panic_on_warn set ... [ 175.482554] [ 175.489909] CPU: 0 PID: 5 Comm: kworker/u4:0 Tainted: G B 4.14.218-syzkaller #0 [ 175.498476] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 175.507827] Workqueue: tipc_rcv tipc_recv_work [ 175.512488] Call Trace: [ 175.515071] dump_stack+0x1b2/0x281 [ 175.518780] panic+0x1f9/0x42d [ 175.521965] ? add_taint.cold+0x16/0x16 [ 175.525917] ? lock_downgrade+0x740/0x740 [ 175.530043] kasan_end_report+0x43/0x49 [ 175.534016] kasan_report_error.cold+0xa7/0x191 [ 175.538677] ? __lock_acquire+0x2c57/0x3f20 [ 175.542992] __asan_report_load8_noabort+0x68/0x70 [ 175.547913] ? tipc_subscrb_rcv_cb+0x2c0/0xa40 [ 175.552483] ? __lock_acquire+0x2c57/0x3f20 [ 175.556792] __lock_acquire+0x2c57/0x3f20 [ 175.560928] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 175.565918] ? _raw_spin_unlock_irq+0x5a/0x80 [ 175.570404] ? finish_task_switch+0x178/0x610 [ 175.574886] ? finish_task_switch+0x14d/0x610 [ 175.580138] ? trace_hardirqs_on+0x10/0x10 [ 175.584346] ? trace_hardirqs_on+0x10/0x10 [ 175.588561] ? rcu_read_unlock_special+0x776/0xdd0 [ 175.593569] ? mark_held_locks+0xa6/0xf0 [ 175.597604] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 175.602693] lock_acquire+0x170/0x3f0 [ 175.606485] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 175.611059] _raw_spin_lock_bh+0x2f/0x40 [ 175.615189] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 175.619749] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 175.624136] tipc_receive_from_sock+0x25c/0x450 [ 175.628784] ? trace_hardirqs_on+0x10/0x10 [ 175.632993] ? lock_acquire+0x170/0x3f0 [ 175.636953] ? tipc_close_conn+0x200/0x200 [ 175.641173] tipc_recv_work+0x75/0xd0 [ 175.644956] process_one_work+0x793/0x14a0 [ 175.649170] ? work_busy+0x320/0x320 [ 175.652875] ? worker_thread+0x158/0xff0 [ 175.656910] ? _raw_spin_unlock_irq+0x24/0x80 [ 175.661379] worker_thread+0x5cc/0xff0 [ 175.665251] ? rescuer_thread+0xc80/0xc80 [ 175.669375] kthread+0x30d/0x420 [ 175.672726] ? kthread_create_on_node+0xd0/0xd0 [ 175.678344] ret_from_fork+0x24/0x30 [ 175.682697] Kernel Offset: disabled [ 175.686415] Rebooting in 86400 seconds..