[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty1. [ OK ] Started Getty on tty2. [ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.196' (ECDSA) to the list of known hosts. 2020/06/19 00:05:26 fuzzer started 2020/06/19 00:05:26 connecting to host at 10.128.0.26:35453 2020/06/19 00:05:26 checking machine... 2020/06/19 00:05:26 checking revisions... 2020/06/19 00:05:26 testing simple program... syzkaller login: [ 64.184805][ T6829] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 00:05:26 building call list... [ 64.567098][ T39] tipc: TX() has been purged, node left! [ 65.089451][ T39] ================================================================== [ 65.097878][ T39] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 65.105786][ T39] Write of size 1 at addr ffff8880a01db1e4 by task kworker/u4:2/39 [ 65.113667][ T39] [ 65.116001][ T39] CPU: 0 PID: 39 Comm: kworker/u4:2 Not tainted 5.8.0-rc1-syzkaller #0 [ 65.124231][ T39] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.134393][ T39] Workqueue: netns cleanup_net [ 65.139150][ T39] Call Trace: [ 65.142706][ T39] dump_stack+0x18f/0x20d [ 65.147042][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.153630][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.159173][ T39] ? afs_put_call+0xa40/0xa40 [ 65.165334][ T39] print_address_description.constprop.0.cold+0xd3/0x413 [ 65.172804][ T39] ? vprintk_func+0x97/0x1a6 [ 65.177426][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.182999][ T39] kasan_report.cold+0x1f/0x37 [ 65.187768][ T39] ? rcu_read_lock_held_common+0x51/0xa0 [ 65.193608][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.199159][ T39] afs_wake_up_async_call+0x6aa/0x770 [ 65.204547][ T39] ? afs_close_socket+0x320/0x320 [ 65.209580][ T39] ? afs_put_call+0xa40/0xa40 [ 65.214256][ T39] rxrpc_notify_socket+0x1db/0x5d0 [ 65.219400][ T39] ? afs_put_call+0xa40/0xa40 [ 65.224083][ T39] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 65.230506][ T39] rxrpc_call_completed+0xca/0xf0 [ 65.235538][ T39] rxrpc_discard_prealloc+0x781/0xab0 [ 65.241100][ T39] ? lock_sock_nested+0x94/0x110 [ 65.246138][ T39] rxrpc_listen+0x147/0x360 [ 65.250669][ T39] afs_close_socket+0x95/0x320 [ 65.257196][ T39] ? afs_purge_servers+0x16d/0x300 [ 65.262411][ T39] ? afs_rx_discard_new_call+0x50/0x50 [ 65.267876][ T39] ? init_wait_var_entry+0x200/0x200 [ 65.273171][ T39] ? rcu_read_lock_held_common+0xa0/0xa0 [ 65.278829][ T39] ? check_preemption_disabled+0x38/0x220 [ 65.285179][ T39] afs_net_exit+0x1bc/0x310 [ 65.290486][ T39] ? afs_net_init+0xe30/0xe30 [ 65.295169][ T39] ops_exit_list.isra.0+0xa8/0x150 [ 65.300930][ T39] cleanup_net+0x511/0xa50 [ 65.305379][ T39] ? unregister_pernet_device+0x70/0x70 [ 65.311580][ T39] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 65.317836][ T39] process_one_work+0x965/0x1690 [ 65.322902][ T39] ? lock_release+0x800/0x800 [ 65.327581][ T39] ? pwq_dec_nr_in_flight+0x310/0x310 [ 65.332980][ T39] ? rwlock_bug.part.0+0x90/0x90 [ 65.338035][ T39] worker_thread+0x96/0xe10 [ 65.342557][ T39] ? process_one_work+0x1690/0x1690 [ 65.347760][ T39] kthread+0x3b5/0x4a0 [ 65.352005][ T39] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 65.357724][ T39] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 65.363471][ T39] ret_from_fork+0x1f/0x30 [ 65.367902][ T39] [ 65.370230][ T39] Allocated by task 6829: [ 65.374587][ T39] save_stack+0x1b/0x40 [ 65.378930][ T39] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 65.384603][ T39] kmem_cache_alloc_trace+0x153/0x7d0 [ 65.389988][ T39] afs_alloc_call+0x55/0x630 [ 65.394671][ T39] afs_charge_preallocation+0xe9/0x2d0 [ 65.400131][ T39] afs_open_socket+0x292/0x360 [ 65.404897][ T39] afs_net_init+0xa6c/0xe30 [ 65.409605][ T39] ops_init+0xaf/0x420 [ 65.413728][ T39] setup_net+0x2de/0x860 [ 65.417975][ T39] copy_net_ns+0x293/0x590 [ 65.422417][ T39] create_new_namespaces+0x3fb/0xb30 [ 65.427708][ T39] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 65.433340][ T39] ksys_unshare+0x43d/0x8e0 [ 65.437866][ T39] __x64_sys_unshare+0x2d/0x40 [ 65.443985][ T39] do_syscall_64+0x60/0xe0 [ 65.448544][ T39] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 65.454469][ T39] [ 65.456808][ T39] Freed by task 39: [ 65.460638][ T39] save_stack+0x1b/0x40 [ 65.464832][ T39] __kasan_slab_free+0xf7/0x140 [ 65.469710][ T39] kfree+0x109/0x2b0 [ 65.473639][ T39] afs_put_call+0x585/0xa40 [ 65.478172][ T39] rxrpc_discard_prealloc+0x764/0xab0 [ 65.483590][ T39] rxrpc_listen+0x147/0x360 [ 65.488130][ T39] afs_close_socket+0x95/0x320 [ 65.493175][ T39] afs_net_exit+0x1bc/0x310 [ 65.497894][ T39] ops_exit_list.isra.0+0xa8/0x150 [ 65.503029][ T39] cleanup_net+0x511/0xa50 [ 65.507454][ T39] process_one_work+0x965/0x1690 [ 65.512410][ T39] worker_thread+0x96/0xe10 [ 65.517097][ T39] kthread+0x3b5/0x4a0 [ 65.521173][ T39] ret_from_fork+0x1f/0x30 [ 65.525589][ T39] [ 65.527937][ T39] The buggy address belongs to the object at ffff8880a01db000 [ 65.527937][ T39] which belongs to the cache kmalloc-1k of size 1024 [ 65.542147][ T39] The buggy address is located 484 bytes inside of [ 65.542147][ T39] 1024-byte region [ffff8880a01db000, ffff8880a01db400) [ 65.555653][ T39] The buggy address belongs to the page: [ 65.561313][ T39] page:ffffea00028076c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 65.570461][ T39] flags: 0xfffe0000000200(slab) [ 65.576195][ T39] raw: 00fffe0000000200 ffffea00028096c8 ffffea0002802408 ffff8880aa000c40 [ 65.585046][ T39] raw: 0000000000000000 ffff8880a01db000 0000000100000002 0000000000000000 [ 65.593714][ T39] page dumped because: kasan: bad access detected [ 65.600309][ T39] [ 65.602807][ T39] Memory state around the buggy address: [ 65.608438][ T39] ffff8880a01db080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 65.616547][ T39] ffff8880a01db100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 65.624617][ T39] >ffff8880a01db180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 65.632684][ T39] ^ [ 65.639917][ T39] ffff8880a01db200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 65.648146][ T39] ffff8880a01db280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 65.656248][ T39] ================================================================== [ 65.664605][ T39] Disabling lock debugging due to kernel taint [ 65.670805][ T39] Kernel panic - not syncing: panic_on_warn set ... [ 65.677390][ T39] CPU: 0 PID: 39 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 65.687004][ T39] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.697058][ T39] Workqueue: netns cleanup_net [ 65.701829][ T39] Call Trace: [ 65.705148][ T39] dump_stack+0x18f/0x20d [ 65.709503][ T39] ? afs_wake_up_async_call+0x680/0x770 [ 65.715064][ T39] ? afs_put_call+0xa40/0xa40 [ 65.719753][ T39] panic+0x2e3/0x75c [ 65.724008][ T39] ? __warn_printk+0xf3/0xf3 [ 65.728621][ T39] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 65.734922][ T39] ? trace_hardirqs_on+0x55/0x220 [ 65.740042][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.745585][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.751125][ T39] ? afs_put_call+0xa40/0xa40 [ 65.755816][ T39] end_report+0x4d/0x53 [ 65.759989][ T39] kasan_report.cold+0xd/0x37 [ 65.764698][ T39] ? rcu_read_lock_held_common+0x51/0xa0 [ 65.770326][ T39] ? afs_wake_up_async_call+0x6aa/0x770 [ 65.775866][ T39] afs_wake_up_async_call+0x6aa/0x770 [ 65.781317][ T39] ? afs_close_socket+0x320/0x320 [ 65.786345][ T39] ? afs_put_call+0xa40/0xa40 [ 65.791042][ T39] rxrpc_notify_socket+0x1db/0x5d0 [ 65.796177][ T39] ? afs_put_call+0xa40/0xa40 [ 65.800852][ T39] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 65.807262][ T39] rxrpc_call_completed+0xca/0xf0 [ 65.812299][ T39] rxrpc_discard_prealloc+0x781/0xab0 [ 65.817676][ T39] ? lock_sock_nested+0x94/0x110 [ 65.822612][ T39] rxrpc_listen+0x147/0x360 [ 65.827114][ T39] afs_close_socket+0x95/0x320 [ 65.831982][ T39] ? afs_purge_servers+0x16d/0x300 [ 65.837096][ T39] ? afs_rx_discard_new_call+0x50/0x50 [ 65.842551][ T39] ? init_wait_var_entry+0x200/0x200 [ 65.847835][ T39] ? rcu_read_lock_held_common+0xa0/0xa0 [ 65.853482][ T39] ? check_preemption_disabled+0x38/0x220 [ 65.859201][ T39] afs_net_exit+0x1bc/0x310 [ 65.863699][ T39] ? afs_net_init+0xe30/0xe30 [ 65.868499][ T39] ops_exit_list.isra.0+0xa8/0x150 [ 65.873608][ T39] cleanup_net+0x511/0xa50 [ 65.878023][ T39] ? unregister_pernet_device+0x70/0x70 [ 65.883565][ T39] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 65.889547][ T39] process_one_work+0x965/0x1690 [ 65.894763][ T39] ? lock_release+0x800/0x800 [ 65.899434][ T39] ? pwq_dec_nr_in_flight+0x310/0x310 [ 65.904820][ T39] ? rwlock_bug.part.0+0x90/0x90 [ 65.909768][ T39] worker_thread+0x96/0xe10 [ 65.914301][ T39] ? process_one_work+0x1690/0x1690 [ 65.919585][ T39] kthread+0x3b5/0x4a0 [ 65.923658][ T39] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 65.929369][ T39] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 65.935096][ T39] ret_from_fork+0x1f/0x30 [ 65.940933][ T39] Kernel Offset: disabled [ 65.945512][ T39] Rebooting in 86400 seconds..