[ OK ] Started OpenBSD Secure Shell server. [ 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 '10.128.0.10' (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 syzkaller login: [ 28.267922] ================================================================== [ 28.275385] BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 [ 28.282025] Read of size 8 at addr ffff8880b445dfa0 by task kworker/u4:2/25 [ 28.289098] [ 28.290710] CPU: 0 PID: 25 Comm: kworker/u4:2 Not tainted 4.14.302-syzkaller #0 [ 28.298126] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 [ 28.307460] Workqueue: tipc_rcv tipc_recv_work [ 28.312016] Call Trace: [ 28.314578] dump_stack+0x1b2/0x281 [ 28.318182] print_address_description.cold+0x54/0x1d3 [ 28.323434] kasan_report_error.cold+0x8a/0x191 [ 28.328079] ? __lock_acquire+0x2c57/0x3f20 [ 28.332377] __asan_report_load8_noabort+0x68/0x70 [ 28.337286] ? tipc_subscrb_rcv_cb+0x2f0/0xa40 [ 28.341843] ? __lock_acquire+0x2c57/0x3f20 [ 28.346142] __lock_acquire+0x2c57/0x3f20 [ 28.350267] ? io_schedule_timeout+0x140/0x140 [ 28.354827] ? __wake_up_common_lock+0xcd/0x140 [ 28.359469] ? trace_hardirqs_on+0x10/0x10 [ 28.363687] ? trace_hardirqs_on+0x10/0x10 [ 28.367905] ? preempt_schedule_common+0x45/0xc0 [ 28.372636] ? ___preempt_schedule+0x16/0x18 [ 28.377052] ? tipc_recvmsg+0x43e/0x9e0 [ 28.380997] ? __local_bh_enable_ip+0x132/0x170 [ 28.385727] lock_acquire+0x170/0x3f0 [ 28.389499] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.394056] _raw_spin_lock_bh+0x2f/0x40 [ 28.398090] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.402728] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.407111] tipc_receive_from_sock+0x25c/0x450 [ 28.411930] ? trace_hardirqs_on+0x10/0x10 [ 28.416140] ? tipc_close_conn+0x200/0x200 [ 28.420350] tipc_recv_work+0x75/0xd0 [ 28.424126] process_one_work+0x793/0x14a0 [ 28.428338] ? work_busy+0x320/0x320 [ 28.432027] ? worker_thread+0x158/0xff0 [ 28.436060] ? _raw_spin_unlock_irq+0x24/0x80 [ 28.440527] worker_thread+0x5cc/0xff0 [ 28.444409] ? rescuer_thread+0xc80/0xc80 [ 28.448720] kthread+0x30d/0x420 [ 28.452147] ? kthread_create_on_node+0xd0/0xd0 [ 28.456789] ret_from_fork+0x24/0x30 [ 28.460477] [ 28.462077] Allocated by task 25: [ 28.465502] kasan_kmalloc+0xeb/0x160 [ 28.469280] kmem_cache_alloc_trace+0x131/0x3d0 [ 28.473924] tipc_subscrb_connect_cb+0x40/0x150 [ 28.478565] tipc_accept_from_sock+0x25b/0x400 [ 28.483130] tipc_recv_work+0x75/0xd0 [ 28.486904] process_one_work+0x793/0x14a0 [ 28.491109] worker_thread+0x5cc/0xff0 [ 28.495141] kthread+0x30d/0x420 [ 28.498478] ret_from_fork+0x24/0x30 [ 28.502160] [ 28.503759] Freed by task 2881: [ 28.507010] kasan_slab_free+0xc3/0x1a0 [ 28.510954] kfree+0xc9/0x250 [ 28.514051] tipc_subscrb_put+0x22/0x30 [ 28.517996] tipc_close_conn+0x16a/0x200 [ 28.522028] tipc_send_work+0x41e/0x520 [ 28.525973] process_one_work+0x793/0x14a0 [ 28.530184] worker_thread+0x5cc/0xff0 [ 28.534041] kthread+0x30d/0x420 [ 28.537379] ret_from_fork+0x24/0x30 [ 28.541059] [ 28.542659] The buggy address belongs to the object at ffff8880b445df80 [ 28.542659] which belongs to the cache kmalloc-96 of size 96 [ 28.555118] The buggy address is located 32 bytes inside of [ 28.555118] 96-byte region [ffff8880b445df80, ffff8880b445dfe0) [ 28.566785] The buggy address belongs to the page: [ 28.571686] page:ffffea0002d11740 count:1 mapcount:0 mapping:ffff8880b445d000 index:0xffff8880b445dc80 [ 28.581105] flags: 0xfff00000000100(slab) [ 28.585225] raw: 00fff00000000100 ffff8880b445d000 ffff8880b445dc80 0000000100000002 [ 28.593076] raw: ffffea0002642be0 ffffea0002d43560 ffff88813fe744c0 0000000000000000 [ 28.600925] page dumped because: kasan: bad access detected [ 28.606603] [ 28.608202] Memory state around the buggy address: [ 28.613103] ffff8880b445de80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc [ 28.620434] ffff8880b445df00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 28.627764] >ffff8880b445df80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 28.635094] ^ [ 28.639471] ffff8880b445e000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 28.646798] ffff8880b445e080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 28.654126] ================================================================== [ 28.661453] Disabling lock debugging due to kernel taint [ 28.666874] Kernel panic - not syncing: panic_on_warn set ... [ 28.666874] [ 28.674207] CPU: 0 PID: 25 Comm: kworker/u4:2 Tainted: G B 4.14.302-syzkaller #0 [ 28.682837] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 [ 28.692171] Workqueue: tipc_rcv tipc_recv_work [ 28.696724] Call Trace: [ 28.699302] dump_stack+0x1b2/0x281 [ 28.702921] panic+0x1f9/0x42d [ 28.706099] ? add_taint.cold+0x16/0x16 [ 28.710055] ? lock_downgrade+0x740/0x740 [ 28.714185] kasan_end_report+0x43/0x49 [ 28.718138] kasan_report_error.cold+0xa7/0x191 [ 28.722781] ? __lock_acquire+0x2c57/0x3f20 [ 28.727078] __asan_report_load8_noabort+0x68/0x70 [ 28.731985] ? tipc_subscrb_rcv_cb+0x2f0/0xa40 [ 28.736543] ? __lock_acquire+0x2c57/0x3f20 [ 28.740838] __lock_acquire+0x2c57/0x3f20 [ 28.744973] ? io_schedule_timeout+0x140/0x140 [ 28.749635] ? __wake_up_common_lock+0xcd/0x140 [ 28.754283] ? trace_hardirqs_on+0x10/0x10 [ 28.758495] ? trace_hardirqs_on+0x10/0x10 [ 28.762713] ? preempt_schedule_common+0x45/0xc0 [ 28.767543] ? ___preempt_schedule+0x16/0x18 [ 28.771931] ? tipc_recvmsg+0x43e/0x9e0 [ 28.775891] ? __local_bh_enable_ip+0x132/0x170 [ 28.780540] lock_acquire+0x170/0x3f0 [ 28.784321] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.788880] _raw_spin_lock_bh+0x2f/0x40 [ 28.793011] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.797636] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 28.802025] tipc_receive_from_sock+0x25c/0x450 [ 28.806672] ? trace_hardirqs_on+0x10/0x10 [ 28.810883] ? tipc_close_conn+0x200/0x200 [ 28.815095] tipc_recv_work+0x75/0xd0 [ 28.818879] process_one_work+0x793/0x14a0 [ 28.823091] ? work_busy+0x320/0x320 [ 28.826780] ? worker_thread+0x158/0xff0 [ 28.830817] ? _raw_spin_unlock_irq+0x24/0x80 [ 28.835289] worker_thread+0x5cc/0xff0 [ 28.839182] ? rescuer_thread+0xc80/0xc80 [ 28.843305] kthread+0x30d/0x420 [ 28.846647] ? kthread_create_on_node+0xd0/0xd0 [ 28.851290] ret_from_fork+0x24/0x30 [ 28.855134] Kernel Offset: disabled [ 28.858737] Rebooting in 86400 seconds..