[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.148' (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: [ 49.068480] audit: type=1400 audit(1598155590.055:8): avc: denied { execmem } for pid=6360 comm="syz-executor019" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 49.589354] ================================================================== [ 49.596737] BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 [ 49.603383] Read of size 8 at addr ffff88808c00b220 by task kworker/u4:2/96 [ 49.610449] [ 49.612051] CPU: 0 PID: 96 Comm: kworker/u4:2 Not tainted 4.14.194-syzkaller #0 [ 49.619479] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.628815] Workqueue: tipc_rcv tipc_recv_work [ 49.633380] Call Trace: [ 49.635938] dump_stack+0x1b2/0x283 [ 49.639539] print_address_description.cold+0x54/0x1d3 [ 49.644801] kasan_report_error.cold+0x8a/0x194 [ 49.649443] ? __lock_acquire+0x2c57/0x3f20 [ 49.653735] __asan_report_load8_noabort+0x68/0x70 [ 49.658637] ? tipc_subscrb_rcv_cb+0x2d0/0xa40 [ 49.663225] ? __lock_acquire+0x2c57/0x3f20 [ 49.667520] __lock_acquire+0x2c57/0x3f20 [ 49.671643] ? io_schedule_timeout+0x140/0x140 [ 49.676202] ? __wake_up_common_lock+0xcd/0x140 [ 49.680855] ? trace_hardirqs_on+0x10/0x10 [ 49.685068] ? trace_hardirqs_on+0x10/0x10 [ 49.689281] ? preempt_schedule_common+0x45/0xc0 [ 49.694011] ? ___preempt_schedule+0x16/0x18 [ 49.698392] ? tipc_recvmsg+0x436/0x9d0 [ 49.702338] ? __local_bh_enable_ip+0x132/0x170 [ 49.706995] lock_acquire+0x170/0x3f0 [ 49.710768] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 49.715324] _raw_spin_lock_bh+0x2f/0x40 [ 49.719367] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 49.723936] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 49.728317] tipc_receive_from_sock+0x25c/0x450 [ 49.732955] ? trace_hardirqs_on+0x10/0x10 [ 49.737159] ? lock_acquire+0x170/0x3f0 [ 49.741100] ? tipc_close_conn+0x200/0x200 [ 49.745307] tipc_recv_work+0x75/0xd0 [ 49.749081] process_one_work+0x793/0x14a0 [ 49.753304] ? work_busy+0x320/0x320 [ 49.757001] ? worker_thread+0x158/0xff0 [ 49.761044] ? _raw_spin_unlock_irq+0x24/0x80 [ 49.765509] worker_thread+0x5cc/0xff0 [ 49.769368] ? rescuer_thread+0xc80/0xc80 [ 49.773499] kthread+0x30d/0x420 [ 49.776851] ? kthread_create_on_node+0xd0/0xd0 [ 49.781499] ret_from_fork+0x24/0x30 [ 49.785193] [ 49.786791] Allocated by task 22: [ 49.790231] kasan_kmalloc+0xeb/0x160 [ 49.794002] kmem_cache_alloc_trace+0x131/0x3d0 [ 49.798654] tipc_subscrb_connect_cb+0x40/0x150 [ 49.803302] tipc_accept_from_sock+0x25b/0x400 [ 49.807853] tipc_recv_work+0x75/0xd0 [ 49.811623] process_one_work+0x793/0x14a0 [ 49.815828] worker_thread+0x5cc/0xff0 [ 49.819686] kthread+0x30d/0x420 [ 49.823034] ret_from_fork+0x24/0x30 [ 49.826714] [ 49.828310] Freed by task 5: [ 49.831300] kasan_slab_free+0xc3/0x1a0 [ 49.835244] kfree+0xc9/0x250 [ 49.838338] tipc_subscrb_put+0x22/0x30 [ 49.842280] tipc_close_conn+0x16a/0x200 [ 49.846313] tipc_send_work+0x41e/0x520 [ 49.850259] process_one_work+0x793/0x14a0 [ 49.854462] worker_thread+0x5cc/0xff0 [ 49.858316] kthread+0x30d/0x420 [ 49.861652] ret_from_fork+0x24/0x30 [ 49.865330] [ 49.866945] The buggy address belongs to the object at ffff88808c00b200 [ 49.866945] which belongs to the cache kmalloc-96 of size 96 [ 49.879403] The buggy address is located 32 bytes inside of [ 49.879403] 96-byte region [ffff88808c00b200, ffff88808c00b260) [ 49.891160] The buggy address belongs to the page: [ 49.896070] page:ffffea00023002c0 count:1 mapcount:0 mapping:ffff88808c00b000 index:0x0 [ 49.904186] flags: 0xfffe0000000100(slab) [ 49.908306] raw: 00fffe0000000100 ffff88808c00b000 0000000000000000 0000000100000020 [ 49.916167] raw: ffffea00022cf0a0 ffffea00029523e0 ffff88812fe524c0 0000000000000000 [ 49.924020] page dumped because: kasan: bad access detected [ 49.929715] [ 49.931358] Memory state around the buggy address: [ 49.936267] ffff88808c00b100: 00 00 00 00 00 00 00 00 04 fc fc fc fc fc fc fc [ 49.944293] ffff88808c00b180: 00 00 00 00 00 00 00 00 04 fc fc fc fc fc fc fc [ 49.951624] >ffff88808c00b200: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 49.958951] ^ [ 49.963328] ffff88808c00b280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 49.970659] ffff88808c00b300: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc [ 49.978256] ================================================================== [ 49.985584] Disabling lock debugging due to kernel taint [ 49.991012] Kernel panic - not syncing: panic_on_warn set ... [ 49.991012] [ 49.998358] CPU: 0 PID: 96 Comm: kworker/u4:2 Tainted: G B 4.14.194-syzkaller #0 [ 50.007003] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.016350] Workqueue: tipc_rcv tipc_recv_work [ 50.020919] Call Trace: [ 50.023497] dump_stack+0x1b2/0x283 [ 50.027103] panic+0x1f9/0x42d [ 50.030266] ? add_taint.cold+0x16/0x16 [ 50.034213] ? lock_downgrade+0x740/0x740 [ 50.038336] kasan_end_report+0x43/0x49 [ 50.042281] kasan_report_error.cold+0xa7/0x194 [ 50.047018] ? __lock_acquire+0x2c57/0x3f20 [ 50.051321] __asan_report_load8_noabort+0x68/0x70 [ 50.056234] ? tipc_subscrb_rcv_cb+0x2d0/0xa40 [ 50.060798] ? __lock_acquire+0x2c57/0x3f20 [ 50.065097] __lock_acquire+0x2c57/0x3f20 [ 50.069220] ? io_schedule_timeout+0x140/0x140 [ 50.073774] ? __wake_up_common_lock+0xcd/0x140 [ 50.078425] ? trace_hardirqs_on+0x10/0x10 [ 50.082648] ? trace_hardirqs_on+0x10/0x10 [ 50.086856] ? preempt_schedule_common+0x45/0xc0 [ 50.091584] ? ___preempt_schedule+0x16/0x18 [ 50.095963] ? tipc_recvmsg+0x436/0x9d0 [ 50.099909] ? __local_bh_enable_ip+0x132/0x170 [ 50.104549] lock_acquire+0x170/0x3f0 [ 50.108337] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 50.112891] _raw_spin_lock_bh+0x2f/0x40 [ 50.116923] ? tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 50.121475] tipc_subscrb_rcv_cb+0x4d4/0xa40 [ 50.125863] tipc_receive_from_sock+0x25c/0x450 [ 50.130516] ? trace_hardirqs_on+0x10/0x10 [ 50.134721] ? lock_acquire+0x170/0x3f0 [ 50.138667] ? tipc_close_conn+0x200/0x200 [ 50.142885] tipc_recv_work+0x75/0xd0 [ 50.146669] process_one_work+0x793/0x14a0 [ 50.150886] ? work_busy+0x320/0x320 [ 50.154581] ? worker_thread+0x158/0xff0 [ 50.158614] ? _raw_spin_unlock_irq+0x24/0x80 [ 50.163081] worker_thread+0x5cc/0xff0 [ 50.166954] ? rescuer_thread+0xc80/0xc80 [ 50.171073] kthread+0x30d/0x420 [ 50.174419] ? kthread_create_on_node+0xd0/0xd0 [ 50.179064] ret_from_fork+0x24/0x30 [ 50.183718] Kernel Offset: disabled [ 50.187326] Rebooting in 86400 seconds..