[ 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 '10.128.0.8' (ECDSA) to the list of known hosts. 2020/06/19 05:10:29 fuzzer started 2020/06/19 05:10:29 connecting to host at 10.128.0.26:40237 2020/06/19 05:10:29 checking machine... 2020/06/19 05:10:29 checking revisions... 2020/06/19 05:10:29 testing simple program... syzkaller login: [ 62.229932][ T6819] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 05:10:29 building call list... [ 62.555713][ T96] tipc: TX() has been purged, node left! [ 63.057803][ T96] ================================================================== [ 63.066161][ T96] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 63.074046][ T96] Write of size 1 at addr ffff8880a00c31e4 by task kworker/u4:3/96 [ 63.081931][ T96] [ 63.084262][ T96] CPU: 0 PID: 96 Comm: kworker/u4:3 Not tainted 5.8.0-rc1-syzkaller #0 [ 63.092489][ T96] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.102563][ T96] Workqueue: netns cleanup_net [ 63.107327][ T96] Call Trace: [ 63.110619][ T96] dump_stack+0x18f/0x20d [ 63.114976][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.120620][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.126174][ T96] ? afs_put_call+0xa40/0xa40 [ 63.130864][ T96] print_address_description.constprop.0.cold+0xd3/0x413 [ 63.139894][ T96] ? vprintk_func+0x97/0x1a6 [ 63.144489][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.150030][ T96] kasan_report.cold+0x1f/0x37 [ 63.154823][ T96] ? rcu_read_lock_held_common+0x51/0xa0 [ 63.160459][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.166014][ T96] afs_wake_up_async_call+0x6aa/0x770 [ 63.174336][ T96] ? afs_close_socket+0x320/0x320 [ 63.179360][ T96] ? afs_put_call+0xa40/0xa40 [ 63.184037][ T96] rxrpc_notify_socket+0x1db/0x5d0 [ 63.189154][ T96] ? afs_put_call+0xa40/0xa40 [ 63.193835][ T96] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.200250][ T96] rxrpc_call_completed+0xca/0xf0 [ 63.205278][ T96] rxrpc_discard_prealloc+0x781/0xab0 [ 63.210648][ T96] ? lock_sock_nested+0x94/0x110 [ 63.215881][ T96] rxrpc_listen+0x147/0x360 [ 63.220381][ T96] afs_close_socket+0x95/0x320 [ 63.225141][ T96] ? afs_purge_servers+0x16d/0x300 [ 63.230251][ T96] ? afs_rx_discard_new_call+0x50/0x50 [ 63.235713][ T96] ? init_wait_var_entry+0x200/0x200 [ 63.241003][ T96] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.246634][ T96] ? check_preemption_disabled+0x38/0x220 [ 63.252371][ T96] afs_net_exit+0x1bc/0x310 [ 63.256879][ T96] ? afs_net_init+0xe30/0xe30 [ 63.261552][ T96] ops_exit_list.isra.0+0xa8/0x150 [ 63.266878][ T96] cleanup_net+0x511/0xa50 [ 63.271646][ T96] ? unregister_pernet_device+0x70/0x70 [ 63.277199][ T96] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.283189][ T96] process_one_work+0x965/0x1690 [ 63.288224][ T96] ? lock_release+0x800/0x800 [ 63.292902][ T96] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.298299][ T96] ? rwlock_bug.part.0+0x90/0x90 [ 63.303253][ T96] worker_thread+0x96/0xe10 [ 63.307803][ T96] ? process_one_work+0x1690/0x1690 [ 63.313091][ T96] kthread+0x3b5/0x4a0 [ 63.317355][ T96] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.323204][ T96] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.329143][ T96] ret_from_fork+0x1f/0x30 [ 63.333663][ T96] [ 63.335992][ T96] Allocated by task 6819: [ 63.340752][ T96] save_stack+0x1b/0x40 [ 63.345166][ T96] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 63.350843][ T96] kmem_cache_alloc_trace+0x153/0x7d0 [ 63.356332][ T96] afs_alloc_call+0x55/0x630 [ 63.361013][ T96] afs_charge_preallocation+0xe9/0x2d0 [ 63.366553][ T96] afs_open_socket+0x292/0x360 [ 63.371321][ T96] afs_net_init+0xa6c/0xe30 [ 63.375825][ T96] ops_init+0xaf/0x420 [ 63.379893][ T96] setup_net+0x2de/0x860 [ 63.385967][ T96] copy_net_ns+0x293/0x590 [ 63.390394][ T96] create_new_namespaces+0x3fb/0xb30 [ 63.395764][ T96] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 63.401572][ T96] ksys_unshare+0x43d/0x8e0 [ 63.406176][ T96] __x64_sys_unshare+0x2d/0x40 [ 63.410942][ T96] do_syscall_64+0x60/0xe0 [ 63.415355][ T96] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 63.421235][ T96] [ 63.423562][ T96] Freed by task 96: [ 63.427367][ T96] save_stack+0x1b/0x40 [ 63.431517][ T96] __kasan_slab_free+0xf7/0x140 [ 63.436362][ T96] kfree+0x109/0x2b0 [ 63.440257][ T96] afs_put_call+0x585/0xa40 [ 63.444760][ T96] rxrpc_discard_prealloc+0x764/0xab0 [ 63.450260][ T96] rxrpc_listen+0x147/0x360 [ 63.454766][ T96] afs_close_socket+0x95/0x320 [ 63.459529][ T96] afs_net_exit+0x1bc/0x310 [ 63.464042][ T96] ops_exit_list.isra.0+0xa8/0x150 [ 63.469234][ T96] cleanup_net+0x511/0xa50 [ 63.473752][ T96] process_one_work+0x965/0x1690 [ 63.478794][ T96] worker_thread+0x96/0xe10 [ 63.483293][ T96] kthread+0x3b5/0x4a0 [ 63.487536][ T96] ret_from_fork+0x1f/0x30 [ 63.492123][ T96] [ 63.494448][ T96] The buggy address belongs to the object at ffff8880a00c3000 [ 63.494448][ T96] which belongs to the cache kmalloc-1k of size 1024 [ 63.508514][ T96] The buggy address is located 484 bytes inside of [ 63.508514][ T96] 1024-byte region [ffff8880a00c3000, ffff8880a00c3400) [ 63.522158][ T96] The buggy address belongs to the page: [ 63.527923][ T96] page:ffffea00028030c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 63.537136][ T96] flags: 0xfffe0000000200(slab) [ 63.541993][ T96] raw: 00fffe0000000200 ffffea00029c9c08 ffffea000278d248 ffff8880aa000c40 [ 63.550670][ T96] raw: 0000000000000000 ffff8880a00c3000 0000000100000002 0000000000000000 [ 63.559276][ T96] page dumped because: kasan: bad access detected [ 63.565764][ T96] [ 63.568117][ T96] Memory state around the buggy address: [ 63.574061][ T96] ffff8880a00c3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.582321][ T96] ffff8880a00c3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.590772][ T96] >ffff8880a00c3180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.600174][ T96] ^ [ 63.607745][ T96] ffff8880a00c3200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.617209][ T96] ffff8880a00c3280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.625452][ T96] ================================================================== [ 63.633532][ T96] Disabling lock debugging due to kernel taint [ 63.639753][ T96] Kernel panic - not syncing: panic_on_warn set ... [ 63.646465][ T96] CPU: 0 PID: 96 Comm: kworker/u4:3 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 63.656101][ T96] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.666155][ T96] Workqueue: netns cleanup_net [ 63.670905][ T96] Call Trace: [ 63.674288][ T96] dump_stack+0x18f/0x20d [ 63.678650][ T96] ? afs_wake_up_async_call+0x670/0x770 [ 63.684189][ T96] ? afs_put_call+0xa40/0xa40 [ 63.688946][ T96] panic+0x2e3/0x75c [ 63.692839][ T96] ? __warn_printk+0xf3/0xf3 [ 63.697422][ T96] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 63.703657][ T96] ? trace_hardirqs_on+0x55/0x220 [ 63.708727][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.714277][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.719813][ T96] ? afs_put_call+0xa40/0xa40 [ 63.724483][ T96] end_report+0x4d/0x53 [ 63.728719][ T96] kasan_report.cold+0xd/0x37 [ 63.733432][ T96] ? rcu_read_lock_held_common+0x51/0xa0 [ 63.739143][ T96] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.745209][ T96] afs_wake_up_async_call+0x6aa/0x770 [ 63.750577][ T96] ? afs_close_socket+0x320/0x320 [ 63.755594][ T96] ? afs_put_call+0xa40/0xa40 [ 63.760271][ T96] rxrpc_notify_socket+0x1db/0x5d0 [ 63.765391][ T96] ? afs_put_call+0xa40/0xa40 [ 63.770073][ T96] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.777001][ T96] rxrpc_call_completed+0xca/0xf0 [ 63.784577][ T96] rxrpc_discard_prealloc+0x781/0xab0 [ 63.791270][ T96] ? lock_sock_nested+0x94/0x110 [ 63.796225][ T96] rxrpc_listen+0x147/0x360 [ 63.803682][ T96] afs_close_socket+0x95/0x320 [ 63.808568][ T96] ? afs_purge_servers+0x16d/0x300 [ 63.813681][ T96] ? afs_rx_discard_new_call+0x50/0x50 [ 63.819236][ T96] ? init_wait_var_entry+0x200/0x200 [ 63.824514][ T96] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.830163][ T96] ? check_preemption_disabled+0x38/0x220 [ 63.835962][ T96] afs_net_exit+0x1bc/0x310 [ 63.840828][ T96] ? afs_net_init+0xe30/0xe30 [ 63.845497][ T96] ops_exit_list.isra.0+0xa8/0x150 [ 63.850602][ T96] cleanup_net+0x511/0xa50 [ 63.855446][ T96] ? unregister_pernet_device+0x70/0x70 [ 63.861267][ T96] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.867532][ T96] process_one_work+0x965/0x1690 [ 63.872739][ T96] ? lock_release+0x800/0x800 [ 63.877523][ T96] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.884117][ T96] ? rwlock_bug.part.0+0x90/0x90 [ 63.889191][ T96] worker_thread+0x96/0xe10 [ 63.894151][ T96] ? process_one_work+0x1690/0x1690 [ 63.899876][ T96] kthread+0x3b5/0x4a0 [ 63.904321][ T96] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.910144][ T96] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.916738][ T96] ret_from_fork+0x1f/0x30 [ 63.922885][ T96] Kernel Offset: disabled [ 63.927390][ T96] Rebooting in 86400 seconds..