[ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.61' (ECDSA) to the list of known hosts. 2020/06/19 07:26:53 fuzzer started 2020/06/19 07:26:53 connecting to host at 10.128.0.26:37393 2020/06/19 07:26:53 checking machine... 2020/06/19 07:26:53 checking revisions... 2020/06/19 07:26:53 testing simple program... syzkaller login: [ 66.446161][ T6837] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 07:26:54 building call list... [ 66.791788][ T7] tipc: TX() has been purged, node left! [ 67.304230][ T7] ================================================================== [ 67.312469][ T7] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 67.320374][ T7] Write of size 1 at addr ffff8880826fe9e4 by task kworker/u4:0/7 [ 67.328255][ T7] [ 67.330591][ T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0-rc1-syzkaller #0 [ 67.338928][ T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.349008][ T7] Workqueue: netns cleanup_net [ 67.353766][ T7] Call Trace: [ 67.357059][ T7] dump_stack+0x18f/0x20d [ 67.361391][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.366941][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.372483][ T7] ? afs_put_call+0xa40/0xa40 [ 67.377161][ T7] print_address_description.constprop.0.cold+0xd3/0x413 [ 67.384189][ T7] ? vprintk_func+0x97/0x1a6 [ 67.388782][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.394326][ T7] kasan_report.cold+0x1f/0x37 [ 67.399244][ T7] ? rcu_read_lock_held_common+0x51/0xa0 [ 67.404878][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.410444][ T7] afs_wake_up_async_call+0x6aa/0x770 [ 67.415821][ T7] ? afs_close_socket+0x320/0x320 [ 67.420849][ T7] ? afs_put_call+0xa40/0xa40 [ 67.425527][ T7] rxrpc_notify_socket+0x1db/0x5d0 [ 67.430655][ T7] ? afs_put_call+0xa40/0xa40 [ 67.435358][ T7] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 67.441780][ T7] rxrpc_call_completed+0xca/0xf0 [ 67.446810][ T7] rxrpc_discard_prealloc+0x781/0xab0 [ 67.452201][ T7] ? lock_sock_nested+0x94/0x110 [ 67.457154][ T7] rxrpc_listen+0x147/0x360 [ 67.461801][ T7] afs_close_socket+0x95/0x320 [ 67.466589][ T7] ? afs_purge_servers+0x16d/0x300 [ 67.471719][ T7] ? afs_rx_discard_new_call+0x50/0x50 [ 67.477195][ T7] ? init_wait_var_entry+0x200/0x200 [ 67.482491][ T7] ? rcu_read_lock_held_common+0xa0/0xa0 [ 67.488144][ T7] ? check_preemption_disabled+0x38/0x220 [ 67.493913][ T7] afs_net_exit+0x1bc/0x310 [ 67.498422][ T7] ? afs_net_init+0xe30/0xe30 [ 67.503188][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 67.508315][ T7] cleanup_net+0x511/0xa50 [ 67.512742][ T7] ? unregister_pernet_device+0x70/0x70 [ 67.518383][ T7] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 67.524388][ T7] process_one_work+0x965/0x1690 [ 67.529337][ T7] ? lock_release+0x800/0x800 [ 67.534027][ T7] ? pwq_dec_nr_in_flight+0x310/0x310 [ 67.539404][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 67.544365][ T7] worker_thread+0x96/0xe10 [ 67.548888][ T7] ? process_one_work+0x1690/0x1690 [ 67.554094][ T7] kthread+0x3b5/0x4a0 [ 67.558168][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 67.563887][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 67.569609][ T7] ret_from_fork+0x1f/0x30 [ 67.574036][ T7] [ 67.576357][ T7] Allocated by task 6837: [ 67.580734][ T7] save_stack+0x1b/0x40 [ 67.584889][ T7] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 67.590518][ T7] kmem_cache_alloc_trace+0x153/0x7d0 [ 67.595955][ T7] afs_alloc_call+0x55/0x630 [ 67.600546][ T7] afs_charge_preallocation+0xe9/0x2d0 [ 67.605997][ T7] afs_open_socket+0x292/0x360 [ 67.610761][ T7] afs_net_init+0xa6c/0xe30 [ 67.615262][ T7] ops_init+0xaf/0x420 [ 67.619324][ T7] setup_net+0x2de/0x860 [ 67.623563][ T7] copy_net_ns+0x293/0x590 [ 67.627993][ T7] create_new_namespaces+0x3fb/0xb30 [ 67.633534][ T7] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 67.639170][ T7] ksys_unshare+0x43d/0x8e0 [ 67.645752][ T7] __x64_sys_unshare+0x2d/0x40 [ 67.650552][ T7] do_syscall_64+0x60/0xe0 [ 67.654965][ T7] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 67.660933][ T7] [ 67.663264][ T7] Freed by task 7: [ 67.666981][ T7] save_stack+0x1b/0x40 [ 67.671144][ T7] __kasan_slab_free+0xf7/0x140 [ 67.676003][ T7] kfree+0x109/0x2b0 [ 67.679904][ T7] afs_put_call+0x585/0xa40 [ 67.684423][ T7] rxrpc_discard_prealloc+0x764/0xab0 [ 67.689801][ T7] rxrpc_listen+0x147/0x360 [ 67.694324][ T7] afs_close_socket+0x95/0x320 [ 67.699085][ T7] afs_net_exit+0x1bc/0x310 [ 67.703584][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 67.708686][ T7] cleanup_net+0x511/0xa50 [ 67.713102][ T7] process_one_work+0x965/0x1690 [ 67.718037][ T7] worker_thread+0x96/0xe10 [ 67.722536][ T7] kthread+0x3b5/0x4a0 [ 67.726600][ T7] ret_from_fork+0x1f/0x30 [ 67.730999][ T7] [ 67.733333][ T7] The buggy address belongs to the object at ffff8880826fe800 [ 67.733333][ T7] which belongs to the cache kmalloc-1k of size 1024 [ 67.747380][ T7] The buggy address is located 484 bytes inside of [ 67.747380][ T7] 1024-byte region [ffff8880826fe800, ffff8880826fec00) [ 67.760733][ T7] The buggy address belongs to the page: [ 67.766387][ T7] page:ffffea000209bf80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 67.775484][ T7] flags: 0xfffe0000000200(slab) [ 67.780511][ T7] raw: 00fffe0000000200 ffffea000209bf48 ffffea000209c008 ffff8880aa000c40 [ 67.789109][ T7] raw: 0000000000000000 ffff8880826fe000 0000000100000002 0000000000000000 [ 67.797789][ T7] page dumped because: kasan: bad access detected [ 67.804205][ T7] [ 67.806529][ T7] Memory state around the buggy address: [ 67.812181][ T7] ffff8880826fe880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.820240][ T7] ffff8880826fe900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.828296][ T7] >ffff8880826fe980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.836349][ T7] ^ [ 67.843625][ T7] ffff8880826fea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.851702][ T7] ffff8880826fea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.859747][ T7] ================================================================== [ 67.867797][ T7] Disabling lock debugging due to kernel taint [ 67.874014][ T7] Kernel panic - not syncing: panic_on_warn set ... [ 67.880608][ T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 67.890145][ T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.900209][ T7] Workqueue: netns cleanup_net [ 67.904967][ T7] Call Trace: [ 67.908257][ T7] dump_stack+0x18f/0x20d [ 67.912596][ T7] ? afs_wake_up_async_call+0x680/0x770 [ 67.918149][ T7] ? afs_put_call+0xa40/0xa40 [ 67.922827][ T7] panic+0x2e3/0x75c [ 67.926721][ T7] ? __warn_printk+0xf3/0xf3 [ 67.931306][ T7] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 67.937456][ T7] ? trace_hardirqs_on+0x55/0x220 [ 67.942474][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.948007][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.953540][ T7] ? afs_put_call+0xa40/0xa40 [ 67.958217][ T7] end_report+0x4d/0x53 [ 67.962367][ T7] kasan_report.cold+0xd/0x37 [ 67.967049][ T7] ? rcu_read_lock_held_common+0x51/0xa0 [ 67.973089][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 67.978627][ T7] afs_wake_up_async_call+0x6aa/0x770 [ 67.983987][ T7] ? afs_close_socket+0x320/0x320 [ 67.989173][ T7] ? afs_put_call+0xa40/0xa40 [ 67.993839][ T7] rxrpc_notify_socket+0x1db/0x5d0 [ 67.998951][ T7] ? afs_put_call+0xa40/0xa40 [ 68.003616][ T7] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 68.010036][ T7] rxrpc_call_completed+0xca/0xf0 [ 68.015070][ T7] rxrpc_discard_prealloc+0x781/0xab0 [ 68.020444][ T7] ? lock_sock_nested+0x94/0x110 [ 68.025393][ T7] rxrpc_listen+0x147/0x360 [ 68.029892][ T7] afs_close_socket+0x95/0x320 [ 68.034650][ T7] ? afs_purge_servers+0x16d/0x300 [ 68.039844][ T7] ? afs_rx_discard_new_call+0x50/0x50 [ 68.045299][ T7] ? init_wait_var_entry+0x200/0x200 [ 68.050664][ T7] ? rcu_read_lock_held_common+0xa0/0xa0 [ 68.056306][ T7] ? check_preemption_disabled+0x38/0x220 [ 68.062540][ T7] afs_net_exit+0x1bc/0x310 [ 68.067123][ T7] ? afs_net_init+0xe30/0xe30 [ 68.071792][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 68.076919][ T7] cleanup_net+0x511/0xa50 [ 68.081412][ T7] ? unregister_pernet_device+0x70/0x70 [ 68.087130][ T7] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 68.093102][ T7] process_one_work+0x965/0x1690 [ 68.098036][ T7] ? lock_release+0x800/0x800 [ 68.102716][ T7] ? pwq_dec_nr_in_flight+0x310/0x310 [ 68.108079][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 68.113013][ T7] worker_thread+0x96/0xe10 [ 68.117521][ T7] ? process_one_work+0x1690/0x1690 [ 68.122706][ T7] kthread+0x3b5/0x4a0 [ 68.126786][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 68.132494][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 68.138214][ T7] ret_from_fork+0x1f/0x30 [ 68.144088][ T7] Kernel Offset: disabled [ 68.149418][ T7] Rebooting in 86400 seconds..