[ OK ] Started Getty on tty2. [ 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 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 '10.128.0.72' (ECDSA) to the list of known hosts. 2020/06/19 00:46:39 fuzzer started 2020/06/19 00:46:39 connecting to host at 10.128.0.26:41123 2020/06/19 00:46:39 checking machine... 2020/06/19 00:46:39 checking revisions... 2020/06/19 00:46:39 testing simple program... syzkaller login: [ 60.228634][ T6825] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 00:46:39 building call list... [ 60.530020][ T26] tipc: TX() has been purged, node left! [ 61.052173][ T26] ================================================================== [ 61.060600][ T26] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.068594][ T26] Write of size 1 at addr ffff8880a79851e4 by task kworker/u4:2/26 [ 61.076476][ T26] [ 61.078981][ T26] CPU: 1 PID: 26 Comm: kworker/u4:2 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.087206][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.097299][ T26] Workqueue: netns cleanup_net [ 61.102057][ T26] Call Trace: [ 61.105362][ T26] dump_stack+0x18f/0x20d [ 61.109699][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.115239][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.120804][ T26] ? afs_put_call+0xa40/0xa40 [ 61.125487][ T26] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.132684][ T26] ? vprintk_func+0x97/0x1a6 [ 61.137277][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.142819][ T26] kasan_report.cold+0x1f/0x37 [ 61.147602][ T26] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.153231][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.158780][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 61.164148][ T26] ? afs_close_socket+0x320/0x320 [ 61.169199][ T26] ? afs_put_call+0xa40/0xa40 [ 61.173876][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 61.178993][ T26] ? afs_put_call+0xa40/0xa40 [ 61.185320][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.191740][ T26] rxrpc_call_completed+0xca/0xf0 [ 61.196788][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 61.202163][ T26] ? lock_sock_nested+0x94/0x110 [ 61.207106][ T26] rxrpc_listen+0x147/0x360 [ 61.211630][ T26] afs_close_socket+0x95/0x320 [ 61.216404][ T26] ? afs_purge_servers+0x16d/0x300 [ 61.221528][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 61.227004][ T26] ? init_wait_var_entry+0x200/0x200 [ 61.232295][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.238274][ T26] ? check_preemption_disabled+0x38/0x220 [ 61.243994][ T26] afs_net_exit+0x1bc/0x310 [ 61.248505][ T26] ? afs_net_init+0xe30/0xe30 [ 61.253176][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.258306][ T26] cleanup_net+0x511/0xa50 [ 61.262723][ T26] ? unregister_pernet_device+0x70/0x70 [ 61.268296][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.274286][ T26] process_one_work+0x965/0x1690 [ 61.279257][ T26] ? lock_release+0x800/0x800 [ 61.284051][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.289526][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 61.294501][ T26] worker_thread+0x96/0xe10 [ 61.299212][ T26] ? process_one_work+0x1690/0x1690 [ 61.304458][ T26] kthread+0x3b5/0x4a0 [ 61.308550][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.314623][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.320437][ T26] ret_from_fork+0x1f/0x30 [ 61.324871][ T26] [ 61.327191][ T26] Allocated by task 6825: [ 61.331866][ T26] save_stack+0x1b/0x40 [ 61.336021][ T26] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 61.341650][ T26] kmem_cache_alloc_trace+0x153/0x7d0 [ 61.347229][ T26] afs_alloc_call+0x55/0x630 [ 61.351821][ T26] afs_charge_preallocation+0xe9/0x2d0 [ 61.357450][ T26] afs_open_socket+0x292/0x360 [ 61.362316][ T26] afs_net_init+0xa6c/0xe30 [ 61.366900][ T26] ops_init+0xaf/0x420 [ 61.371073][ T26] setup_net+0x2de/0x860 [ 61.375322][ T26] copy_net_ns+0x293/0x590 [ 61.379745][ T26] create_new_namespaces+0x3fb/0xb30 [ 61.385042][ T26] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 61.390678][ T26] ksys_unshare+0x43d/0x8e0 [ 61.395188][ T26] __x64_sys_unshare+0x2d/0x40 [ 61.399948][ T26] do_syscall_64+0x60/0xe0 [ 61.404359][ T26] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 61.410239][ T26] [ 61.412576][ T26] Freed by task 26: [ 61.416383][ T26] save_stack+0x1b/0x40 [ 61.420539][ T26] __kasan_slab_free+0xf7/0x140 [ 61.425598][ T26] kfree+0x109/0x2b0 [ 61.429589][ T26] afs_put_call+0x585/0xa40 [ 61.434088][ T26] rxrpc_discard_prealloc+0x764/0xab0 [ 61.439459][ T26] rxrpc_listen+0x147/0x360 [ 61.443959][ T26] afs_close_socket+0x95/0x320 [ 61.448727][ T26] afs_net_exit+0x1bc/0x310 [ 61.453267][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.458373][ T26] cleanup_net+0x511/0xa50 [ 61.462788][ T26] process_one_work+0x965/0x1690 [ 61.467805][ T26] worker_thread+0x96/0xe10 [ 61.472399][ T26] kthread+0x3b5/0x4a0 [ 61.476489][ T26] ret_from_fork+0x1f/0x30 [ 61.480898][ T26] [ 61.483228][ T26] The buggy address belongs to the object at ffff8880a7985000 [ 61.483228][ T26] which belongs to the cache kmalloc-1k of size 1024 [ 61.497303][ T26] The buggy address is located 484 bytes inside of [ 61.497303][ T26] 1024-byte region [ffff8880a7985000, ffff8880a7985400) [ 61.510650][ T26] The buggy address belongs to the page: [ 61.516457][ T26] page:ffffea00029e6140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 61.525755][ T26] flags: 0xfffe0000000200(slab) [ 61.530613][ T26] raw: 00fffe0000000200 ffffea0002582d88 ffffea000258fd88 ffff8880aa000c40 [ 61.539315][ T26] raw: 0000000000000000 ffff8880a7985000 0000000100000002 0000000000000000 [ 61.548188][ T26] page dumped because: kasan: bad access detected [ 61.554758][ T26] [ 61.557096][ T26] Memory state around the buggy address: [ 61.562761][ T26] ffff8880a7985080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.570916][ T26] ffff8880a7985100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.579339][ T26] >ffff8880a7985180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.587485][ T26] ^ [ 61.594684][ T26] ffff8880a7985200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.602749][ T26] ffff8880a7985280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.610809][ T26] ================================================================== [ 61.618875][ T26] Disabling lock debugging due to kernel taint [ 61.625085][ T26] Kernel panic - not syncing: panic_on_warn set ... [ 61.631691][ T26] CPU: 1 PID: 26 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 61.641407][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.651475][ T26] Workqueue: netns cleanup_net [ 61.656221][ T26] Call Trace: [ 61.659517][ T26] dump_stack+0x18f/0x20d [ 61.664283][ T26] ? afs_wake_up_async_call+0x670/0x770 [ 61.669835][ T26] ? afs_put_call+0xa40/0xa40 [ 61.674518][ T26] panic+0x2e3/0x75c [ 61.678420][ T26] ? __warn_printk+0xf3/0xf3 [ 61.683015][ T26] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 61.689188][ T26] ? trace_hardirqs_on+0x55/0x220 [ 61.694224][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.699774][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.705321][ T26] ? afs_put_call+0xa40/0xa40 [ 61.710039][ T26] end_report+0x4d/0x53 [ 61.714200][ T26] kasan_report.cold+0xd/0x37 [ 61.718886][ T26] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.724776][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.730937][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 61.736303][ T26] ? afs_close_socket+0x320/0x320 [ 61.741927][ T26] ? afs_put_call+0xa40/0xa40 [ 61.746610][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 61.751734][ T26] ? afs_put_call+0xa40/0xa40 [ 61.756497][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.762912][ T26] rxrpc_call_completed+0xca/0xf0 [ 61.768079][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 61.773465][ T26] ? lock_sock_nested+0x94/0x110 [ 61.778400][ T26] rxrpc_listen+0x147/0x360 [ 61.782902][ T26] afs_close_socket+0x95/0x320 [ 61.787746][ T26] ? afs_purge_servers+0x16d/0x300 [ 61.792944][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 61.798452][ T26] ? init_wait_var_entry+0x200/0x200 [ 61.803749][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.809400][ T26] ? check_preemption_disabled+0x38/0x220 [ 61.815117][ T26] afs_net_exit+0x1bc/0x310 [ 61.819618][ T26] ? afs_net_init+0xe30/0xe30 [ 61.824287][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.829393][ T26] cleanup_net+0x511/0xa50 [ 61.833807][ T26] ? unregister_pernet_device+0x70/0x70 [ 61.839350][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.845334][ T26] process_one_work+0x965/0x1690 [ 61.850305][ T26] ? lock_release+0x800/0x800 [ 61.854981][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.860359][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 61.865302][ T26] worker_thread+0x96/0xe10 [ 61.869806][ T26] ? process_one_work+0x1690/0x1690 [ 61.875085][ T26] kthread+0x3b5/0x4a0 [ 61.879149][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.884864][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.890590][ T26] ret_from_fork+0x1f/0x30 [ 61.896340][ T26] Kernel Offset: disabled [ 61.900674][ T26] Rebooting in 86400 seconds..