[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 35.953037] random: sshd: uninitialized urandom read (32 bytes read) [ 36.264945] kauditd_printk_skb: 10 callbacks suppressed [ 36.264953] audit: type=1400 audit(1556086942.354:35): avc: denied { map } for pid=6916 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 36.321125] random: sshd: uninitialized urandom read (32 bytes read) [ 36.832523] random: sshd: uninitialized urandom read (32 bytes read) [ 37.012313] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.42' (ECDSA) to the list of known hosts. [ 42.708250] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 42.820219] audit: type=1400 audit(1556086948.904:36): avc: denied { map } for pid=6928 comm="syz-executor327" path="/root/syz-executor327750717" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file 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 [ 43.224870] ================================================================== [ 43.232493] BUG: KASAN: use-after-free in refcount_inc_not_zero+0xd3/0xe0 [ 43.239411] Read of size 4 at addr ffff8880979c1a80 by task kworker/u4:1/22 [ 43.246490] [ 43.248106] CPU: 1 PID: 22 Comm: kworker/u4:1 Not tainted 4.14.113 #3 [ 43.254670] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.264016] Workqueue: tipc_rcv tipc_recv_work [ 43.268591] Call Trace: [ 43.271170] dump_stack+0x138/0x19c [ 43.274786] ? refcount_inc_not_zero+0xd3/0xe0 [ 43.279355] print_address_description.cold+0x7c/0x1dc [ 43.284615] ? refcount_inc_not_zero+0xd3/0xe0 [ 43.289182] kasan_report.cold+0xaf/0x2b5 [ 43.293352] __asan_report_load4_noabort+0x14/0x20 [ 43.298283] refcount_inc_not_zero+0xd3/0xe0 [ 43.302777] refcount_inc+0x16/0x40 [ 43.306401] tipc_subscrb_rcv_cb+0x61d/0xa80 [ 43.310797] tipc_receive_from_sock+0x28a/0x4e0 [ 43.315451] ? trace_hardirqs_on+0x10/0x10 [ 43.319668] ? tipc_send_work+0x5a0/0x5a0 [ 43.323802] ? process_one_work+0x787/0x1610 [ 43.328293] ? __lock_is_held+0xb6/0x140 [ 43.332341] ? check_preemption_disabled+0x3c/0x250 [ 43.337344] tipc_recv_work+0x8b/0xf0 [ 43.341216] process_one_work+0x868/0x1610 [ 43.345438] ? pwq_dec_nr_in_flight+0x2e0/0x2e0 [ 43.350114] worker_thread+0x5d9/0x1050 [ 43.354095] kthread+0x31c/0x430 [ 43.357447] ? process_one_work+0x1610/0x1610 [ 43.361925] ? kthread_create_on_node+0xd0/0xd0 [ 43.366577] ret_from_fork+0x3a/0x50 [ 43.370276] [ 43.371889] Allocated by task 5: [ 43.375238] save_stack_trace+0x16/0x20 [ 43.379302] save_stack+0x45/0xd0 [ 43.382740] kasan_kmalloc+0xce/0xf0 [ 43.386575] kmem_cache_alloc_trace+0x152/0x790 [ 43.391230] tipc_subscrb_connect_cb+0x46/0x160 [ 43.395881] tipc_accept_from_sock+0x280/0x470 [ 43.400617] tipc_recv_work+0x8b/0xf0 [ 43.404398] process_one_work+0x868/0x1610 [ 43.408626] worker_thread+0x5d9/0x1050 [ 43.412619] kthread+0x31c/0x430 [ 43.415967] ret_from_fork+0x3a/0x50 [ 43.419668] [ 43.421276] Freed by task 5: [ 43.424280] save_stack_trace+0x16/0x20 [ 43.428239] save_stack+0x45/0xd0 [ 43.431675] kasan_slab_free+0x75/0xc0 [ 43.435544] kfree+0xcc/0x270 [ 43.438632] tipc_subscrb_put+0x27/0x30 [ 43.442589] tipc_subscrb_release_cb+0x20/0x30 [ 43.447154] tipc_close_conn+0x179/0x210 [ 43.451198] tipc_send_work+0x470/0x5a0 [ 43.455153] process_one_work+0x868/0x1610 [ 43.459455] worker_thread+0x5d9/0x1050 [ 43.463409] kthread+0x31c/0x430 [ 43.466757] ret_from_fork+0x3a/0x50 [ 43.470448] [ 43.472061] The buggy address belongs to the object at ffff8880979c1a80 [ 43.472061] which belongs to the cache kmalloc-96 of size 96 [ 43.484537] The buggy address is located 0 bytes inside of [ 43.484537] 96-byte region [ffff8880979c1a80, ffff8880979c1ae0) [ 43.496148] The buggy address belongs to the page: [ 43.501063] page:ffffea00025e7040 count:1 mapcount:0 mapping:ffff8880979c1000 index:0xffff8880979c1000 [ 43.510492] flags: 0x1fffc0000000100(slab) [ 43.514793] raw: 01fffc0000000100 ffff8880979c1000 ffff8880979c1000 0000000100000008 [ 43.522659] raw: ffffea00023e9be0 ffffea0002482ca0 ffff8880aa8004c0 0000000000000000 [ 43.530525] page dumped because: kasan: bad access detected [ 43.536226] [ 43.537833] Memory state around the buggy address: [ 43.542744] ffff8880979c1980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 43.550084] ffff8880979c1a00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 43.557435] >ffff8880979c1a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 43.564774] ^ [ 43.568121] ffff8880979c1b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc executing program executing program executing program executing program executing program executing program executing program [ 43.575466] ffff8880979c1b80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 43.582818] ================================================================== [ 43.590158] Disabling lock debugging due to kernel taint [ 43.595626] Kernel panic - not syncing: panic_on_warn set ... [ 43.595626] [ 43.603267] CPU: 1 PID: 22 Comm: kworker/u4:1 Tainted: G B 4.14.113 #3 [ 43.611162] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.620526] Workqueue: tipc_rcv tipc_recv_work 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 [ 43.625284] Call Trace: [ 43.627880] dump_stack+0x138/0x19c [ 43.631613] ? refcount_inc_not_zero+0xd3/0xe0 [ 43.636200] panic+0x1f2/0x438 [ 43.639403] ? add_taint.cold+0x16/0x16 [ 43.643388] kasan_end_report+0x47/0x4f [ 43.647452] kasan_report.cold+0x136/0x2b5 [ 43.651691] __asan_report_load4_noabort+0x14/0x20 [ 43.656632] refcount_inc_not_zero+0xd3/0xe0 [ 43.661054] refcount_inc+0x16/0x40 [ 43.664684] tipc_subscrb_rcv_cb+0x61d/0xa80 [ 43.669097] tipc_receive_from_sock+0x28a/0x4e0 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 [ 43.673767] ? trace_hardirqs_on+0x10/0x10 [ 43.678001] ? tipc_send_work+0x5a0/0x5a0 [ 43.682160] ? process_one_work+0x787/0x1610 [ 43.686582] ? __lock_is_held+0xb6/0x140 [ 43.690653] ? check_preemption_disabled+0x3c/0x250 [ 43.695675] tipc_recv_work+0x8b/0xf0 [ 43.699557] process_one_work+0x868/0x1610 [ 43.703796] ? pwq_dec_nr_in_flight+0x2e0/0x2e0 [ 43.708470] worker_thread+0x5d9/0x1050 [ 43.712453] kthread+0x31c/0x430 [ 43.715823] ? process_one_work+0x1610/0x1610 [ 43.720329] ? kthread_create_on_node+0xd0/0xd0 [ 43.724995] ret_from_fork+0x3a/0x50 [ 43.729767] Kernel Offset: disabled [ 43.733386] Rebooting in 86400 seconds..