[ OK ] Started Getty on tty2. Starting Load/Save RF Kill Switch Status... [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ 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 Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.40' (ECDSA) to the list of known hosts. 2020/06/19 03:29:29 fuzzer started 2020/06/19 03:29:29 connecting to host at 10.128.0.26:36581 2020/06/19 03:29:30 checking machine... 2020/06/19 03:29:30 checking revisions... 2020/06/19 03:29:30 testing simple program... syzkaller login: [ 61.325834][ T6828] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 03:29:30 building call list... [ 61.647930][ T7] tipc: TX() has been purged, node left! [ 62.150030][ T7] ================================================================== [ 62.158288][ T7] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 62.166266][ T7] Write of size 1 at addr ffff8880965ad1e4 by task kworker/u4:0/7 [ 62.174242][ T7] [ 62.176573][ T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0-rc1-syzkaller #0 [ 62.184715][ T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.194775][ T7] Workqueue: netns cleanup_net [ 62.199533][ T7] Call Trace: [ 62.203091][ T7] dump_stack+0x18f/0x20d [ 62.207441][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.212986][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.218528][ T7] ? afs_put_call+0xa40/0xa40 [ 62.223223][ T7] print_address_description.constprop.0.cold+0xd3/0x413 [ 62.230271][ T7] ? vprintk_func+0x97/0x1a6 [ 62.234874][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.240420][ T7] kasan_report.cold+0x1f/0x37 [ 62.245278][ T7] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.250914][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.256460][ T7] afs_wake_up_async_call+0x6aa/0x770 [ 62.261827][ T7] ? afs_close_socket+0x320/0x320 [ 62.266851][ T7] ? afs_put_call+0xa40/0xa40 [ 62.271526][ T7] rxrpc_notify_socket+0x1db/0x5d0 [ 62.276733][ T7] ? afs_put_call+0xa40/0xa40 [ 62.281411][ T7] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.287844][ T7] rxrpc_call_completed+0xca/0xf0 [ 62.292902][ T7] rxrpc_discard_prealloc+0x781/0xab0 [ 62.298283][ T7] ? lock_sock_nested+0x94/0x110 [ 62.303226][ T7] rxrpc_listen+0x147/0x360 [ 62.307737][ T7] afs_close_socket+0x95/0x320 [ 62.312498][ T7] ? afs_purge_servers+0x16d/0x300 [ 62.317626][ T7] ? afs_rx_discard_new_call+0x50/0x50 [ 62.323174][ T7] ? init_wait_var_entry+0x200/0x200 [ 62.328488][ T7] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.334118][ T7] ? check_preemption_disabled+0x38/0x220 [ 62.340109][ T7] afs_net_exit+0x1bc/0x310 [ 62.344615][ T7] ? afs_net_init+0xe30/0xe30 [ 62.349294][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 62.354405][ T7] cleanup_net+0x511/0xa50 [ 62.358823][ T7] ? unregister_pernet_device+0x70/0x70 [ 62.364374][ T7] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.370361][ T7] process_one_work+0x965/0x1690 [ 62.375751][ T7] ? lock_release+0x800/0x800 [ 62.380426][ T7] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.385802][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 62.391032][ T7] worker_thread+0x96/0xe10 [ 62.395547][ T7] ? process_one_work+0x1690/0x1690 [ 62.400746][ T7] kthread+0x3b5/0x4a0 [ 62.404818][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.410558][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.416298][ T7] ret_from_fork+0x1f/0x30 [ 62.420744][ T7] [ 62.423070][ T7] Allocated by task 6828: [ 62.427407][ T7] save_stack+0x1b/0x40 [ 62.431560][ T7] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.437188][ T7] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.442552][ T7] afs_alloc_call+0x55/0x630 [ 62.447136][ T7] afs_charge_preallocation+0xe9/0x2d0 [ 62.452589][ T7] afs_open_socket+0x292/0x360 [ 62.457345][ T7] afs_net_init+0xa6c/0xe30 [ 62.461841][ T7] ops_init+0xaf/0x420 [ 62.465905][ T7] setup_net+0x2de/0x860 [ 62.470145][ T7] copy_net_ns+0x293/0x590 [ 62.474565][ T7] create_new_namespaces+0x3fb/0xb30 [ 62.479852][ T7] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.485498][ T7] ksys_unshare+0x43d/0x8e0 [ 62.489997][ T7] __x64_sys_unshare+0x2d/0x40 [ 62.494757][ T7] do_syscall_64+0x60/0xe0 [ 62.499173][ T7] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.505057][ T7] [ 62.507378][ T7] Freed by task 7: [ 62.511096][ T7] save_stack+0x1b/0x40 [ 62.515244][ T7] __kasan_slab_free+0xf7/0x140 [ 62.520086][ T7] kfree+0x109/0x2b0 [ 62.523977][ T7] afs_put_call+0x585/0xa40 [ 62.528475][ T7] rxrpc_discard_prealloc+0x764/0xab0 [ 62.533848][ T7] rxrpc_listen+0x147/0x360 [ 62.538441][ T7] afs_close_socket+0x95/0x320 [ 62.543211][ T7] afs_net_exit+0x1bc/0x310 [ 62.547712][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 62.552814][ T7] cleanup_net+0x511/0xa50 [ 62.557227][ T7] process_one_work+0x965/0x1690 [ 62.562164][ T7] worker_thread+0x96/0xe10 [ 62.566666][ T7] kthread+0x3b5/0x4a0 [ 62.570759][ T7] ret_from_fork+0x1f/0x30 [ 62.575174][ T7] [ 62.577517][ T7] The buggy address belongs to the object at ffff8880965ad000 [ 62.577517][ T7] which belongs to the cache kmalloc-1k of size 1024 [ 62.591571][ T7] The buggy address is located 484 bytes inside of [ 62.591571][ T7] 1024-byte region [ffff8880965ad000, ffff8880965ad400) [ 62.604955][ T7] The buggy address belongs to the page: [ 62.610590][ T7] page:ffffea0002596b40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.619745][ T7] flags: 0xfffe0000000200(slab) [ 62.624610][ T7] raw: 00fffe0000000200 ffffea00029cab08 ffffea0002751208 ffff8880aa000c40 [ 62.633201][ T7] raw: 0000000000000000 ffff8880965ad000 0000000100000002 0000000000000000 [ 62.641773][ T7] page dumped because: kasan: bad access detected [ 62.648172][ T7] [ 62.650492][ T7] Memory state around the buggy address: [ 62.656133][ T7] ffff8880965ad080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.664478][ T7] ffff8880965ad100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.672574][ T7] >ffff8880965ad180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.680649][ T7] ^ [ 62.687859][ T7] ffff8880965ad200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.695922][ T7] ffff8880965ad280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.703976][ T7] ================================================================== [ 62.712029][ T7] Disabling lock debugging due to kernel taint [ 62.718227][ T7] Kernel panic - not syncing: panic_on_warn set ... [ 62.724808][ T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.734332][ T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.744470][ T7] Workqueue: netns cleanup_net [ 62.749391][ T7] Call Trace: [ 62.752681][ T7] dump_stack+0x18f/0x20d [ 62.757004][ T7] ? afs_wake_up_async_call+0x680/0x770 [ 62.762803][ T7] ? afs_put_call+0xa40/0xa40 [ 62.767480][ T7] panic+0x2e3/0x75c [ 62.771378][ T7] ? __warn_printk+0xf3/0xf3 [ 62.775974][ T7] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.782152][ T7] ? trace_hardirqs_on+0x55/0x220 [ 62.787179][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.792731][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.798265][ T7] ? afs_put_call+0xa40/0xa40 [ 62.803106][ T7] end_report+0x4d/0x53 [ 62.807255][ T7] kasan_report.cold+0xd/0x37 [ 62.811937][ T7] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.817563][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.823125][ T7] afs_wake_up_async_call+0x6aa/0x770 [ 62.828491][ T7] ? afs_close_socket+0x320/0x320 [ 62.833594][ T7] ? afs_put_call+0xa40/0xa40 [ 62.838262][ T7] rxrpc_notify_socket+0x1db/0x5d0 [ 62.843367][ T7] ? afs_put_call+0xa40/0xa40 [ 62.848034][ T7] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.854443][ T7] rxrpc_call_completed+0xca/0xf0 [ 62.859489][ T7] rxrpc_discard_prealloc+0x781/0xab0 [ 62.864854][ T7] ? lock_sock_nested+0x94/0x110 [ 62.869783][ T7] rxrpc_listen+0x147/0x360 [ 62.874289][ T7] afs_close_socket+0x95/0x320 [ 62.879044][ T7] ? afs_purge_servers+0x16d/0x300 [ 62.884149][ T7] ? afs_rx_discard_new_call+0x50/0x50 [ 62.889601][ T7] ? init_wait_var_entry+0x200/0x200 [ 62.894962][ T7] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.900589][ T7] ? check_preemption_disabled+0x38/0x220 [ 62.906312][ T7] afs_net_exit+0x1bc/0x310 [ 62.910812][ T7] ? afs_net_init+0xe30/0xe30 [ 62.915477][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 62.920581][ T7] cleanup_net+0x511/0xa50 [ 62.924990][ T7] ? unregister_pernet_device+0x70/0x70 [ 62.930529][ T7] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.936504][ T7] process_one_work+0x965/0x1690 [ 62.941435][ T7] ? lock_release+0x800/0x800 [ 62.946451][ T7] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.951817][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 62.956749][ T7] worker_thread+0x96/0xe10 [ 62.961262][ T7] ? process_one_work+0x1690/0x1690 [ 62.966459][ T7] kthread+0x3b5/0x4a0 [ 62.970522][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.976323][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.982036][ T7] ret_from_fork+0x1f/0x30 [ 62.987831][ T7] Kernel Offset: disabled [ 62.992217][ T7] Rebooting in 86400 seconds..