Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.40' (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 syzkaller login: [ 31.950107] ================================================================== [ 31.957489] BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 [ 31.964130] Read of size 8 at addr ffff8880b35ac7a0 by task kworker/u4:0/5 [ 31.971117] [ 31.972722] CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.264-syzkaller #0 [ 31.980053] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.989392] Workqueue: tipc_rcv tipc_recv_work [ 31.993947] Call Trace: [ 31.996518] dump_stack+0x1b2/0x281 [ 32.000121] print_address_description.cold+0x54/0x1d3 [ 32.005387] kasan_report_error.cold+0x8a/0x191 [ 32.010034] ? __lock_acquire+0x2c57/0x3f20 [ 32.014331] __asan_report_load8_noabort+0x68/0x70 [ 32.019242] ? tipc_subscrb_rcv_cb+0x360/0xa40 [ 32.023799] ? __lock_acquire+0x2c57/0x3f20 [ 32.028099] __lock_acquire+0x2c57/0x3f20 [ 32.032228] ? io_schedule_timeout+0x140/0x140 [ 32.036790] ? __wake_up_common_lock+0xcd/0x140 [ 32.041438] ? trace_hardirqs_on+0x10/0x10 [ 32.045653] ? trace_hardirqs_on+0x10/0x10 [ 32.049866] ? preempt_schedule_common+0x45/0xc0 [ 32.054602] ? ___preempt_schedule+0x16/0x18 [ 32.058989] ? tipc_recvmsg+0x43e/0x9e0 [ 32.062940] ? __local_bh_enable_ip+0x132/0x170 [ 32.067588] lock_acquire+0x170/0x3f0 [ 32.071366] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 32.075943] _raw_spin_lock_bh+0x2f/0x40 [ 32.079982] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 32.084548] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 32.088945] tipc_receive_from_sock+0x25c/0x450 [ 32.093594] ? trace_hardirqs_on+0x10/0x10 [ 32.097808] ? lock_acquire+0x170/0x3f0 [ 32.101757] ? tipc_close_conn+0x200/0x200 [ 32.105985] tipc_recv_work+0x75/0xd0 [ 32.109765] process_one_work+0x793/0x14a0 [ 32.113980] ? work_busy+0x320/0x320 [ 32.117678] ? worker_thread+0x158/0xff0 [ 32.121721] ? _raw_spin_unlock_irq+0x24/0x80 [ 32.126200] worker_thread+0x5cc/0xff0 [ 32.130070] ? rescuer_thread+0xc80/0xc80 [ 32.134196] kthread+0x30d/0x420 [ 32.137545] ? kthread_create_on_node+0xd0/0xd0 [ 32.142194] ret_from_fork+0x24/0x30 [ 32.145893] [ 32.147497] Allocated by task 5: [ 32.150847] kasan_kmalloc+0xeb/0x160 [ 32.154627] kmem_cache_alloc_trace+0x131/0x3d0 [ 32.159274] tipc_subscrb_connect_cb+0x40/0x150 [ 32.163922] tipc_accept_from_sock+0x25b/0x400 [ 32.168482] tipc_recv_work+0x75/0xd0 [ 32.172268] process_one_work+0x793/0x14a0 [ 32.176480] worker_thread+0x5cc/0xff0 [ 32.180346] kthread+0x30d/0x420 [ 32.183691] ret_from_fork+0x24/0x30 [ 32.187376] [ 32.188979] Freed by task 34: [ 32.192065] kasan_slab_free+0xc3/0x1a0 [ 32.196015] kfree+0xc9/0x250 [ 32.199098] tipc_subscrb_put+0x22/0x30 [ 32.203052] tipc_close_conn+0x16a/0x200 [ 32.207092] tipc_send_work+0x41e/0x520 [ 32.211047] process_one_work+0x793/0x14a0 [ 32.215261] worker_thread+0x5cc/0xff0 [ 32.219125] kthread+0x30d/0x420 [ 32.222500] ret_from_fork+0x24/0x30 [ 32.226186] [ 32.227792] The buggy address belongs to the object at ffff8880b35ac780 [ 32.227792] which belongs to the cache kmalloc-96 of size 96 [ 32.240261] The buggy address is located 32 bytes inside of [ 32.240261] 96-byte region [ffff8880b35ac780, ffff8880b35ac7e0) [ 32.251936] The buggy address belongs to the page: [ 32.256841] page:ffffea0002cd6b00 count:1 mapcount:0 mapping:ffff8880b35ac000 index:0xffff8880b35ac600 [ 32.266263] flags: 0xfff00000000100(slab) [ 32.270394] raw: 00fff00000000100 ffff8880b35ac000 ffff8880b35ac600 000000010000000e [ 32.278257] raw: ffffea0002cdbfe0 ffffea0002cf93a0 ffff88813fe744c0 0000000000000000 [ 32.286112] page dumped because: kasan: bad access detected [ 32.291795] [ 32.293397] Memory state around the buggy address: [ 32.298302] ffff8880b35ac680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 32.305634] ffff8880b35ac700: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 32.312967] >ffff8880b35ac780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 32.320301] ^ [ 32.324684] ffff8880b35ac800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 32.332036] ffff8880b35ac880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 32.339377] ================================================================== [ 32.346710] Disabling lock debugging due to kernel taint [ 32.352134] Kernel panic - not syncing: panic_on_warn set ... [ 32.352134] [ 32.359474] CPU: 0 PID: 5 Comm: kworker/u4:0 Tainted: G B 4.14.264-syzkaller #0 [ 32.368028] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.377371] Workqueue: tipc_rcv tipc_recv_work [ 32.381932] Call Trace: [ 32.384502] dump_stack+0x1b2/0x281 [ 32.388109] panic+0x1f9/0x42d [ 32.391279] ? add_taint.cold+0x16/0x16 [ 32.395231] ? lock_downgrade+0x740/0x740 [ 32.399358] kasan_end_report+0x43/0x49 [ 32.403311] kasan_report_error.cold+0xa7/0x191 [ 32.407958] ? __lock_acquire+0x2c57/0x3f20 [ 32.412257] __asan_report_load8_noabort+0x68/0x70 [ 32.417164] ? tipc_subscrb_rcv_cb+0x360/0xa40 [ 32.421721] ? __lock_acquire+0x2c57/0x3f20 [ 32.426022] __lock_acquire+0x2c57/0x3f20 [ 32.430155] ? io_schedule_timeout+0x140/0x140 [ 32.434714] ? __wake_up_common_lock+0xcd/0x140 [ 32.439366] ? trace_hardirqs_on+0x10/0x10 [ 32.443582] ? trace_hardirqs_on+0x10/0x10 [ 32.447793] ? preempt_schedule_common+0x45/0xc0 [ 32.452527] ? ___preempt_schedule+0x16/0x18 [ 32.456918] ? tipc_recvmsg+0x43e/0x9e0 [ 32.460875] ? __local_bh_enable_ip+0x132/0x170 [ 32.465522] lock_acquire+0x170/0x3f0 [ 32.469304] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 32.473870] _raw_spin_lock_bh+0x2f/0x40 [ 32.477914] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 32.482476] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 32.486868] tipc_receive_from_sock+0x25c/0x450 [ 32.491519] ? trace_hardirqs_on+0x10/0x10 [ 32.495734] ? lock_acquire+0x170/0x3f0 [ 32.499686] ? tipc_close_conn+0x200/0x200 [ 32.503902] tipc_recv_work+0x75/0xd0 [ 32.507681] process_one_work+0x793/0x14a0 [ 32.511893] ? work_busy+0x320/0x320 [ 32.515583] ? worker_thread+0x158/0xff0 [ 32.519622] ? _raw_spin_unlock_irq+0x24/0x80 [ 32.524096] worker_thread+0x5cc/0xff0 [ 32.527965] ? rescuer_thread+0xc80/0xc80 [ 32.532091] kthread+0x30d/0x420 [ 32.535436] ? kthread_create_on_node+0xd0/0xd0 [ 32.540082] ret_from_fork+0x24/0x30 [ 32.543931] Kernel Offset: disabled [ 32.547554] Rebooting in 86400 seconds..