[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.4' (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 syzkaller login: [ 30.041619] ================================================================== [ 30.049670] BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 [ 30.056374] Read of size 8 at addr ffff8880a2c38fa0 by task kworker/u4:3/325 [ 30.063637] [ 30.065262] CPU: 1 PID: 325 Comm: kworker/u4:3 Not tainted 4.14.222-syzkaller #0 [ 30.072775] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.082124] Workqueue: tipc_rcv tipc_recv_work [ 30.086684] Call Trace: [ 30.089254] dump_stack+0x1b2/0x281 [ 30.092888] print_address_description.cold+0x54/0x1d3 [ 30.098332] kasan_report_error.cold+0x8a/0x191 [ 30.103006] ? __lock_acquire+0x2c57/0x3f20 [ 30.107320] __asan_report_load8_noabort+0x68/0x70 [ 30.113289] ? tipc_subscrb_rcv_cb+0x340/0xa40 [ 30.117876] ? __lock_acquire+0x2c57/0x3f20 [ 30.122470] __lock_acquire+0x2c57/0x3f20 [ 30.126634] ? io_schedule_timeout+0x140/0x140 [ 30.131201] ? __wake_up_common_lock+0xcd/0x140 [ 30.135990] ? trace_hardirqs_on+0x10/0x10 [ 30.140222] ? trace_hardirqs_on+0x10/0x10 [ 30.144525] ? preempt_schedule_common+0x45/0xc0 [ 30.149259] ? ___preempt_schedule+0x16/0x18 [ 30.153927] ? tipc_recvmsg+0x43e/0x9e0 [ 30.157882] ? __local_bh_enable_ip+0x132/0x170 [ 30.162634] lock_acquire+0x170/0x3f0 [ 30.166441] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 30.171046] _raw_spin_lock_bh+0x2f/0x40 [ 30.175610] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 30.180715] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 30.185328] tipc_receive_from_sock+0x25c/0x450 [ 30.191027] ? trace_hardirqs_on+0x10/0x10 [ 30.195247] ? lock_acquire+0x170/0x3f0 [ 30.199213] ? tipc_close_conn+0x200/0x200 [ 30.203606] tipc_recv_work+0x75/0xd0 [ 30.207398] process_one_work+0x793/0x14a0 [ 30.213808] ? work_busy+0x320/0x320 [ 30.219373] ? worker_thread+0x158/0xff0 [ 30.223523] ? _raw_spin_unlock_irq+0x24/0x80 [ 30.228316] worker_thread+0x5cc/0xff0 [ 30.232381] ? rescuer_thread+0xc80/0xc80 [ 30.236507] kthread+0x30d/0x420 [ 30.239869] ? kthread_create_on_node+0xd0/0xd0 [ 30.244744] ret_from_fork+0x24/0x30 [ 30.248706] [ 30.250671] Allocated by task 325: [ 30.254197] kasan_kmalloc+0xeb/0x160 [ 30.258251] kmem_cache_alloc_trace+0x131/0x3d0 [ 30.263333] tipc_subscrb_connect_cb+0x40/0x150 [ 30.268959] tipc_accept_from_sock+0x25b/0x400 [ 30.273977] tipc_recv_work+0x75/0xd0 [ 30.277756] process_one_work+0x793/0x14a0 [ 30.282114] worker_thread+0x5cc/0xff0 [ 30.286635] kthread+0x30d/0x420 [ 30.290472] ret_from_fork+0x24/0x30 [ 30.294163] [ 30.295766] Freed by task 137: [ 30.298950] kasan_slab_free+0xc3/0x1a0 [ 30.302903] kfree+0xc9/0x250 [ 30.305988] tipc_subscrb_put+0x22/0x30 [ 30.309939] tipc_close_conn+0x16a/0x200 [ 30.313980] tipc_send_work+0x41e/0x520 [ 30.317933] process_one_work+0x793/0x14a0 [ 30.322143] worker_thread+0x5cc/0xff0 [ 30.326006] kthread+0x30d/0x420 [ 30.329351] ret_from_fork+0x24/0x30 [ 30.333045] [ 30.334648] The buggy address belongs to the object at ffff8880a2c38f80 [ 30.334648] which belongs to the cache kmalloc-96 of size 96 [ 30.349670] The buggy address is located 32 bytes inside of [ 30.349670] 96-byte region [ffff8880a2c38f80, ffff8880a2c38fe0) [ 30.361348] The buggy address belongs to the page: [ 30.366272] page:ffffea00028b0e00 count:1 mapcount:0 mapping:ffff8880a2c38000 index:0xffff8880a2c38e80 [ 30.375711] flags: 0xfff00000000100(slab) [ 30.379840] raw: 00fff00000000100 ffff8880a2c38000 ffff8880a2c38e80 0000000100000004 [ 30.387780] raw: ffffea00028c3fe0 ffffea000289b420 ffff88813fe804c0 0000000000000000 [ 30.395737] page dumped because: kasan: bad access detected [ 30.401424] [ 30.403022] Memory state around the buggy address: [ 30.407925] ffff8880a2c38e80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 30.415265] ffff8880a2c38f00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 30.422620] >ffff8880a2c38f80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 30.429974] ^ [ 30.434375] ffff8880a2c39000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.441935] ffff8880a2c39080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc [ 30.450816] ================================================================== [ 30.458532] Disabling lock debugging due to kernel taint [ 30.464152] Kernel panic - not syncing: panic_on_warn set ... [ 30.464152] [ 30.473595] CPU: 1 PID: 325 Comm: kworker/u4:3 Tainted: G B 4.14.222-syzkaller #0 [ 30.482364] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.491729] Workqueue: tipc_rcv tipc_recv_work [ 30.496289] Call Trace: [ 30.498874] dump_stack+0x1b2/0x281 [ 30.502482] panic+0x1f9/0x42d [ 30.505650] ? add_taint.cold+0x16/0x16 [ 30.509603] ? lock_downgrade+0x740/0x740 [ 30.513730] kasan_end_report+0x43/0x49 [ 30.517701] kasan_report_error.cold+0xa7/0x191 [ 30.522351] ? __lock_acquire+0x2c57/0x3f20 [ 30.526673] __asan_report_load8_noabort+0x68/0x70 [ 30.531676] ? tipc_subscrb_rcv_cb+0x340/0xa40 [ 30.536362] ? __lock_acquire+0x2c57/0x3f20 [ 30.540683] __lock_acquire+0x2c57/0x3f20 [ 30.544899] ? io_schedule_timeout+0x140/0x140 [ 30.549843] ? __wake_up_common_lock+0xcd/0x140 [ 30.555290] ? trace_hardirqs_on+0x10/0x10 [ 30.559538] ? trace_hardirqs_on+0x10/0x10 [ 30.563755] ? preempt_schedule_common+0x45/0xc0 [ 30.569636] ? ___preempt_schedule+0x16/0x18 [ 30.574027] ? tipc_recvmsg+0x43e/0x9e0 [ 30.578777] ? __local_bh_enable_ip+0x132/0x170 [ 30.583525] lock_acquire+0x170/0x3f0 [ 30.587402] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 30.591988] _raw_spin_lock_bh+0x2f/0x40 [ 30.596055] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 30.600640] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 30.605153] tipc_receive_from_sock+0x25c/0x450 [ 30.609823] ? trace_hardirqs_on+0x10/0x10 [ 30.614168] ? lock_acquire+0x170/0x3f0 [ 30.618225] ? tipc_close_conn+0x200/0x200 [ 30.622458] tipc_recv_work+0x75/0xd0 [ 30.626347] process_one_work+0x793/0x14a0 [ 30.630583] ? work_busy+0x320/0x320 [ 30.634747] ? worker_thread+0x158/0xff0 [ 30.638803] ? _raw_spin_unlock_irq+0x24/0x80 [ 30.643353] worker_thread+0x5cc/0xff0 [ 30.647225] ? rescuer_thread+0xc80/0xc80 [ 30.651348] kthread+0x30d/0x420 [ 30.654688] ? kthread_create_on_node+0xd0/0xd0 [ 30.659371] ret_from_fork+0x24/0x30 [ 30.663669] Kernel Offset: disabled [ 30.667373] Rebooting in 86400 seconds..