[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.122' (ECDSA) to the list of known hosts. 2020/06/19 08:02:50 fuzzer started 2020/06/19 08:02:50 connecting to host at 10.128.0.26:46613 2020/06/19 08:02:50 checking machine... 2020/06/19 08:02:50 checking revisions... 2020/06/19 08:02:50 testing simple program... syzkaller login: [ 60.912343][ T7014] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 08:02:51 building call list... [ 61.270831][ T57] tipc: TX() has been purged, node left! [ 61.763326][ T57] ================================================================== [ 61.771585][ T57] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.779480][ T57] Write of size 1 at addr ffff8880951699e4 by task kworker/u4:2/57 [ 61.787353][ T57] [ 61.789683][ T57] CPU: 0 PID: 57 Comm: kworker/u4:2 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.797915][ T57] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.807970][ T57] Workqueue: netns cleanup_net [ 61.812724][ T57] Call Trace: [ 61.816032][ T57] dump_stack+0x18f/0x20d [ 61.820365][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.825907][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.831445][ T57] ? afs_put_call+0xa40/0xa40 [ 61.836120][ T57] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.843232][ T57] ? vprintk_func+0x97/0x1a6 [ 61.847826][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.853371][ T57] kasan_report.cold+0x1f/0x37 [ 61.858139][ T57] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.863775][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.869318][ T57] afs_wake_up_async_call+0x6aa/0x770 [ 61.874688][ T57] ? afs_close_socket+0x320/0x320 [ 61.879709][ T57] ? afs_put_call+0xa40/0xa40 [ 61.884384][ T57] rxrpc_notify_socket+0x1db/0x5d0 [ 61.889511][ T57] ? afs_put_call+0xa40/0xa40 [ 61.894188][ T57] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.900604][ T57] rxrpc_call_completed+0xca/0xf0 [ 61.905633][ T57] rxrpc_discard_prealloc+0x781/0xab0 [ 61.911010][ T57] ? lock_sock_nested+0x94/0x110 [ 61.915957][ T57] rxrpc_listen+0x147/0x360 [ 61.920460][ T57] afs_close_socket+0x95/0x320 [ 61.925220][ T57] ? afs_purge_servers+0x16d/0x300 [ 61.930353][ T57] ? afs_rx_discard_new_call+0x50/0x50 [ 61.935816][ T57] ? init_wait_var_entry+0x200/0x200 [ 61.941100][ T57] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.946728][ T57] ? check_preemption_disabled+0x38/0x220 [ 61.952447][ T57] afs_net_exit+0x1bc/0x310 [ 61.956944][ T57] ? afs_net_init+0xe30/0xe30 [ 61.961623][ T57] ops_exit_list.isra.0+0xa8/0x150 [ 61.966733][ T57] cleanup_net+0x511/0xa50 [ 61.971159][ T57] ? unregister_pernet_device+0x70/0x70 [ 61.976708][ T57] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.982690][ T57] process_one_work+0x965/0x1690 [ 61.987640][ T57] ? lock_release+0x800/0x800 [ 61.992318][ T57] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.997690][ T57] ? rwlock_bug.part.0+0x90/0x90 [ 62.002634][ T57] worker_thread+0x96/0xe10 [ 62.007145][ T57] ? process_one_work+0x1690/0x1690 [ 62.012341][ T57] kthread+0x3b5/0x4a0 [ 62.016407][ T57] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.022118][ T57] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.027835][ T57] ret_from_fork+0x1f/0x30 [ 62.032257][ T57] [ 62.034578][ T57] Allocated by task 7014: [ 62.038916][ T57] save_stack+0x1b/0x40 [ 62.043068][ T57] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.048693][ T57] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.054069][ T57] afs_alloc_call+0x55/0x630 [ 62.058658][ T57] afs_charge_preallocation+0xe9/0x2d0 [ 62.064108][ T57] afs_open_socket+0x292/0x360 [ 62.068866][ T57] afs_net_init+0xa6c/0xe30 [ 62.073363][ T57] ops_init+0xaf/0x420 [ 62.077425][ T57] setup_net+0x2de/0x860 [ 62.081661][ T57] copy_net_ns+0x293/0x590 [ 62.086071][ T57] create_new_namespaces+0x3fb/0xb30 [ 62.091349][ T57] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.096973][ T57] ksys_unshare+0x43d/0x8e0 [ 62.101475][ T57] __x64_sys_unshare+0x2d/0x40 [ 62.106231][ T57] do_syscall_64+0x60/0xe0 [ 62.110640][ T57] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.116513][ T57] [ 62.118836][ T57] Freed by task 57: [ 62.122637][ T57] save_stack+0x1b/0x40 [ 62.126783][ T57] __kasan_slab_free+0xf7/0x140 [ 62.131653][ T57] kfree+0x109/0x2b0 [ 62.135544][ T57] afs_put_call+0x585/0xa40 [ 62.140045][ T57] rxrpc_discard_prealloc+0x764/0xab0 [ 62.145409][ T57] rxrpc_listen+0x147/0x360 [ 62.149906][ T57] afs_close_socket+0x95/0x320 [ 62.154668][ T57] afs_net_exit+0x1bc/0x310 [ 62.159186][ T57] ops_exit_list.isra.0+0xa8/0x150 [ 62.164301][ T57] cleanup_net+0x511/0xa50 [ 62.168735][ T57] process_one_work+0x965/0x1690 [ 62.173685][ T57] worker_thread+0x96/0xe10 [ 62.178187][ T57] kthread+0x3b5/0x4a0 [ 62.182251][ T57] ret_from_fork+0x1f/0x30 [ 62.186649][ T57] [ 62.188970][ T57] The buggy address belongs to the object at ffff888095169800 [ 62.188970][ T57] which belongs to the cache kmalloc-1k of size 1024 [ 62.203015][ T57] The buggy address is located 484 bytes inside of [ 62.203015][ T57] 1024-byte region [ffff888095169800, ffff888095169c00) [ 62.216357][ T57] The buggy address belongs to the page: [ 62.221985][ T57] page:ffffea0002545a40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.231080][ T57] flags: 0xfffe0000000200(slab) [ 62.235930][ T57] raw: 00fffe0000000200 ffffea0002a408c8 ffffea0002787b08 ffff8880aa000c40 [ 62.244511][ T57] raw: 0000000000000000 ffff888095169000 0000000100000002 0000000000000000 [ 62.253078][ T57] page dumped because: kasan: bad access detected [ 62.259475][ T57] [ 62.261790][ T57] Memory state around the buggy address: [ 62.267415][ T57] ffff888095169880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.275469][ T57] ffff888095169900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.283524][ T57] >ffff888095169980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.291573][ T57] ^ [ 62.298758][ T57] ffff888095169a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.306812][ T57] ffff888095169a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.314858][ T57] ================================================================== [ 62.322904][ T57] Disabling lock debugging due to kernel taint [ 62.329102][ T57] Kernel panic - not syncing: panic_on_warn set ... [ 62.335688][ T57] CPU: 0 PID: 57 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.345302][ T57] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.355358][ T57] Workqueue: netns cleanup_net [ 62.360109][ T57] Call Trace: [ 62.363401][ T57] dump_stack+0x18f/0x20d [ 62.367731][ T57] ? afs_wake_up_async_call+0x670/0x770 [ 62.373273][ T57] ? afs_put_call+0xa40/0xa40 [ 62.377945][ T57] panic+0x2e3/0x75c [ 62.381835][ T57] ? __warn_printk+0xf3/0xf3 [ 62.386420][ T57] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.392593][ T57] ? trace_hardirqs_on+0x55/0x220 [ 62.397611][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.403143][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.408680][ T57] ? afs_put_call+0xa40/0xa40 [ 62.413349][ T57] end_report+0x4d/0x53 [ 62.417499][ T57] kasan_report.cold+0xd/0x37 [ 62.422178][ T57] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.427980][ T57] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.433518][ T57] afs_wake_up_async_call+0x6aa/0x770 [ 62.438885][ T57] ? afs_close_socket+0x320/0x320 [ 62.443901][ T57] ? afs_put_call+0xa40/0xa40 [ 62.448568][ T57] rxrpc_notify_socket+0x1db/0x5d0 [ 62.453678][ T57] ? afs_put_call+0xa40/0xa40 [ 62.458345][ T57] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.464752][ T57] rxrpc_call_completed+0xca/0xf0 [ 62.469768][ T57] rxrpc_discard_prealloc+0x781/0xab0 [ 62.475135][ T57] ? lock_sock_nested+0x94/0x110 [ 62.480083][ T57] rxrpc_listen+0x147/0x360 [ 62.484581][ T57] afs_close_socket+0x95/0x320 [ 62.489335][ T57] ? afs_purge_servers+0x16d/0x300 [ 62.494438][ T57] ? afs_rx_discard_new_call+0x50/0x50 [ 62.499887][ T57] ? init_wait_var_entry+0x200/0x200 [ 62.505162][ T57] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.510785][ T57] ? check_preemption_disabled+0x38/0x220 [ 62.516492][ T57] afs_net_exit+0x1bc/0x310 [ 62.521002][ T57] ? afs_net_init+0xe30/0xe30 [ 62.525692][ T57] ops_exit_list.isra.0+0xa8/0x150 [ 62.530794][ T57] cleanup_net+0x511/0xa50 [ 62.535201][ T57] ? unregister_pernet_device+0x70/0x70 [ 62.540738][ T57] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.546711][ T57] process_one_work+0x965/0x1690 [ 62.551643][ T57] ? lock_release+0x800/0x800 [ 62.556310][ T57] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.561672][ T57] ? rwlock_bug.part.0+0x90/0x90 [ 62.566605][ T57] worker_thread+0x96/0xe10 [ 62.571110][ T57] ? process_one_work+0x1690/0x1690 [ 62.576385][ T57] kthread+0x3b5/0x4a0 [ 62.580448][ T57] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.586153][ T57] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.591863][ T57] ret_from_fork+0x1f/0x30 [ 62.597400][ T57] Kernel Offset: disabled [ 62.601714][ T57] Rebooting in 86400 seconds..