[ OK ] Reached target Multi-User System. [ 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 '10.128.0.143' (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 syzkaller login: [ 28.271697] ================================================================== [ 28.279078] BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 [ 28.285718] Read of size 8 at addr ffff88809aca2020 by task kworker/u4:0/5 [ 28.292703] [ 28.294309] CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.280-syzkaller #0 [ 28.301644] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.310981] Workqueue: tipc_rcv tipc_recv_work [ 28.315546] Call Trace: [ 28.318110] dump_stack+0x1b2/0x281 [ 28.321713] print_address_description.cold+0x54/0x1d3 [ 28.326966] kasan_report_error.cold+0x8a/0x191 [ 28.331612] ? __lock_acquire+0x2c57/0x3f20 [ 28.335906] __asan_report_load8_noabort+0x68/0x70 [ 28.340814] ? tipc_subscrb_rcv_cb+0x2c0/0xa40 [ 28.345371] ? __lock_acquire+0x2c57/0x3f20 [ 28.349667] __lock_acquire+0x2c57/0x3f20 [ 28.353797] ? io_schedule_timeout+0x140/0x140 [ 28.358355] ? __wake_up_common_lock+0xcd/0x140 [ 28.362998] ? trace_hardirqs_on+0x10/0x10 [ 28.367209] ? trace_hardirqs_on+0x10/0x10 [ 28.371441] ? preempt_schedule_common+0x45/0xc0 [ 28.376174] ? ___preempt_schedule+0x16/0x18 [ 28.380558] ? tipc_recvmsg+0x43e/0x9e0 [ 28.384506] ? __local_bh_enable_ip+0x132/0x170 [ 28.389152] lock_acquire+0x170/0x3f0 [ 28.392930] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.397485] _raw_spin_lock_bh+0x2f/0x40 [ 28.401518] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.406073] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.410466] tipc_receive_from_sock+0x25c/0x450 [ 28.415112] ? trace_hardirqs_on+0x10/0x10 [ 28.419322] ? lock_acquire+0x170/0x3f0 [ 28.423274] ? tipc_close_conn+0x200/0x200 [ 28.427484] tipc_recv_work+0x75/0xd0 [ 28.431263] process_one_work+0x793/0x14a0 [ 28.435472] ? work_busy+0x320/0x320 [ 28.439157] ? worker_thread+0x158/0xff0 [ 28.443196] ? _raw_spin_unlock_irq+0x24/0x80 [ 28.447665] worker_thread+0x5cc/0xff0 [ 28.451532] ? rescuer_thread+0xc80/0xc80 [ 28.455651] kthread+0x30d/0x420 [ 28.458993] ? kthread_create_on_node+0xd0/0xd0 [ 28.463636] ret_from_fork+0x24/0x30 [ 28.467325] [ 28.468930] Allocated by task 5: [ 28.472274] kasan_kmalloc+0xeb/0x160 [ 28.476048] kmem_cache_alloc_trace+0x131/0x3d0 [ 28.480792] tipc_subscrb_connect_cb+0x40/0x150 [ 28.485435] tipc_accept_from_sock+0x25b/0x400 [ 28.489994] tipc_recv_work+0x75/0xd0 [ 28.493771] process_one_work+0x793/0x14a0 [ 28.497981] worker_thread+0x5cc/0xff0 [ 28.501841] kthread+0x30d/0x420 [ 28.505182] ret_from_fork+0x24/0x30 [ 28.508866] [ 28.510469] Freed by task 22: [ 28.513549] kasan_slab_free+0xc3/0x1a0 [ 28.517496] kfree+0xc9/0x250 [ 28.520575] tipc_subscrb_put+0x22/0x30 [ 28.524546] tipc_close_conn+0x16a/0x200 [ 28.528580] tipc_send_work+0x41e/0x520 [ 28.532527] process_one_work+0x793/0x14a0 [ 28.536759] worker_thread+0x5cc/0xff0 [ 28.540620] kthread+0x30d/0x420 [ 28.543962] ret_from_fork+0x24/0x30 [ 28.547645] [ 28.549248] The buggy address belongs to the object at ffff88809aca2000 [ 28.549248] which belongs to the cache kmalloc-96 of size 96 [ 28.561704] The buggy address is located 32 bytes inside of [ 28.561704] 96-byte region [ffff88809aca2000, ffff88809aca2060) [ 28.573376] The buggy address belongs to the page: [ 28.578278] page:ffffea00026b2880 count:1 mapcount:0 mapping:ffff88809aca2000 index:0xffff88809aca2680 [ 28.587714] flags: 0xfff00000000100(slab) [ 28.591846] raw: 00fff00000000100 ffff88809aca2000 ffff88809aca2680 0000000100000005 [ 28.599716] raw: ffffea0002d09660 ffffea0002d017a0 ffff88813fe744c0 0000000000000000 [ 28.607570] page dumped because: kasan: bad access detected [ 28.613251] [ 28.614854] Memory state around the buggy address: [ 28.619760] ffff88809aca1f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 28.627101] ffff88809aca1f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 28.634439] >ffff88809aca2000: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 28.641769] ^ [ 28.646148] ffff88809aca2080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 28.653480] ffff88809aca2100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 28.660810] ================================================================== [ 28.668140] Disabling lock debugging due to kernel taint [ 28.673563] Kernel panic - not syncing: panic_on_warn set ... [ 28.673563] [ 28.680988] CPU: 0 PID: 5 Comm: kworker/u4:0 Tainted: G B 4.14.280-syzkaller #0 [ 28.689536] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.699331] Workqueue: tipc_rcv tipc_recv_work [ 28.703884] Call Trace: [ 28.706449] dump_stack+0x1b2/0x281 [ 28.710057] panic+0x1f9/0x42d [ 28.713224] ? add_taint.cold+0x16/0x16 [ 28.717173] ? lock_downgrade+0x740/0x740 [ 28.721297] kasan_end_report+0x43/0x49 [ 28.725244] kasan_report_error.cold+0xa7/0x191 [ 28.729886] ? __lock_acquire+0x2c57/0x3f20 [ 28.734181] __asan_report_load8_noabort+0x68/0x70 [ 28.739086] ? tipc_subscrb_rcv_cb+0x2c0/0xa40 [ 28.743638] ? __lock_acquire+0x2c57/0x3f20 [ 28.747943] __lock_acquire+0x2c57/0x3f20 [ 28.752068] ? io_schedule_timeout+0x140/0x140 [ 28.756798] ? __wake_up_common_lock+0xcd/0x140 [ 28.761439] ? trace_hardirqs_on+0x10/0x10 [ 28.765645] ? trace_hardirqs_on+0x10/0x10 [ 28.769853] ? preempt_schedule_common+0x45/0xc0 [ 28.774650] ? ___preempt_schedule+0x16/0x18 [ 28.779034] ? tipc_recvmsg+0x43e/0x9e0 [ 28.782987] ? __local_bh_enable_ip+0x132/0x170 [ 28.787629] lock_acquire+0x170/0x3f0 [ 28.791406] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.795970] _raw_spin_lock_bh+0x2f/0x40 [ 28.800006] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.804563] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.808954] tipc_receive_from_sock+0x25c/0x450 [ 28.813601] ? trace_hardirqs_on+0x10/0x10 [ 28.817812] ? lock_acquire+0x170/0x3f0 [ 28.821770] ? tipc_close_conn+0x200/0x200 [ 28.825981] tipc_recv_work+0x75/0xd0 [ 28.829761] process_one_work+0x793/0x14a0 [ 28.833969] ? work_busy+0x320/0x320 [ 28.837655] ? worker_thread+0x158/0xff0 [ 28.841689] ? _raw_spin_unlock_irq+0x24/0x80 [ 28.846158] worker_thread+0x5cc/0xff0 [ 28.850021] ? rescuer_thread+0xc80/0xc80 [ 28.854144] kthread+0x30d/0x420 [ 28.857485] ? kthread_create_on_node+0xd0/0xd0 [ 28.862133] ret_from_fork+0x24/0x30 [ 28.866068] Kernel Offset: disabled [ 28.869674] Rebooting in 86400 seconds..