[ OK ] Started Getty on tty2. Starting Load/Save RF Kill Switch Status... [ 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 Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.45' (ECDSA) to the list of known hosts. 2020/06/19 08:40:43 fuzzer started 2020/06/19 08:40:43 connecting to host at 10.128.0.26:45105 2020/06/19 08:40:43 checking machine... 2020/06/19 08:40:43 checking revisions... 2020/06/19 08:40:43 testing simple program... syzkaller login: [ 60.917628][ T6813] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 08:40:43 building call list... [ 61.247531][ T26] tipc: TX() has been purged, node left! [ 61.760041][ T26] ================================================================== [ 61.768319][ T26] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.776231][ T26] Write of size 1 at addr ffff8880a683b1e4 by task kworker/u4:2/26 [ 61.784106][ T26] [ 61.786447][ T26] CPU: 1 PID: 26 Comm: kworker/u4:2 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.794671][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.804742][ T26] Workqueue: netns cleanup_net [ 61.809496][ T26] Call Trace: [ 61.812787][ T26] dump_stack+0x18f/0x20d [ 61.817116][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.822658][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.828205][ T26] ? afs_put_call+0xa40/0xa40 [ 61.832885][ T26] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.839929][ T26] ? vprintk_func+0x97/0x1a6 [ 61.844535][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.850078][ T26] kasan_report.cold+0x1f/0x37 [ 61.854845][ T26] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.860473][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.866026][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 61.871849][ T26] ? afs_close_socket+0x320/0x320 [ 61.876888][ T26] ? afs_put_call+0xa40/0xa40 [ 61.881577][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 61.886693][ T26] ? afs_put_call+0xa40/0xa40 [ 61.891377][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.897789][ T26] rxrpc_call_completed+0xca/0xf0 [ 61.902821][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 61.908223][ T26] ? lock_sock_nested+0x94/0x110 [ 61.913162][ T26] rxrpc_listen+0x147/0x360 [ 61.917670][ T26] afs_close_socket+0x95/0x320 [ 61.922437][ T26] ? afs_purge_servers+0x16d/0x300 [ 61.927546][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 61.933006][ T26] ? init_wait_var_entry+0x200/0x200 [ 61.938294][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.943925][ T26] ? check_preemption_disabled+0x38/0x220 [ 61.949648][ T26] afs_net_exit+0x1bc/0x310 [ 61.954149][ T26] ? afs_net_init+0xe30/0xe30 [ 61.958827][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.963944][ T26] cleanup_net+0x511/0xa50 [ 61.968362][ T26] ? unregister_pernet_device+0x70/0x70 [ 61.974257][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.980244][ T26] process_one_work+0x965/0x1690 [ 61.985204][ T26] ? lock_release+0x800/0x800 [ 61.989896][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.995283][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 62.000243][ T26] worker_thread+0x96/0xe10 [ 62.004765][ T26] ? process_one_work+0x1690/0x1690 [ 62.010921][ T26] kthread+0x3b5/0x4a0 [ 62.014988][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.020721][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.026447][ T26] ret_from_fork+0x1f/0x30 [ 62.030871][ T26] [ 62.033193][ T26] Allocated by task 6813: [ 62.037539][ T26] save_stack+0x1b/0x40 [ 62.041706][ T26] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.047371][ T26] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.052738][ T26] afs_alloc_call+0x55/0x630 [ 62.057325][ T26] afs_charge_preallocation+0xe9/0x2d0 [ 62.062873][ T26] afs_open_socket+0x292/0x360 [ 62.067628][ T26] afs_net_init+0xa6c/0xe30 [ 62.072125][ T26] ops_init+0xaf/0x420 [ 62.076280][ T26] setup_net+0x2de/0x860 [ 62.080518][ T26] copy_net_ns+0x293/0x590 [ 62.084931][ T26] create_new_namespaces+0x3fb/0xb30 [ 62.090220][ T26] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.095852][ T26] ksys_unshare+0x43d/0x8e0 [ 62.100353][ T26] __x64_sys_unshare+0x2d/0x40 [ 62.105110][ T26] do_syscall_64+0x60/0xe0 [ 62.109520][ T26] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.115394][ T26] [ 62.117713][ T26] Freed by task 26: [ 62.121515][ T26] save_stack+0x1b/0x40 [ 62.125663][ T26] __kasan_slab_free+0xf7/0x140 [ 62.130509][ T26] kfree+0x109/0x2b0 [ 62.134400][ T26] afs_put_call+0x585/0xa40 [ 62.138907][ T26] rxrpc_discard_prealloc+0x764/0xab0 [ 62.144286][ T26] rxrpc_listen+0x147/0x360 [ 62.148789][ T26] afs_close_socket+0x95/0x320 [ 62.153550][ T26] afs_net_exit+0x1bc/0x310 [ 62.158140][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 62.163246][ T26] cleanup_net+0x511/0xa50 [ 62.167668][ T26] process_one_work+0x965/0x1690 [ 62.172599][ T26] worker_thread+0x96/0xe10 [ 62.177094][ T26] kthread+0x3b5/0x4a0 [ 62.181174][ T26] ret_from_fork+0x1f/0x30 [ 62.185922][ T26] [ 62.188248][ T26] The buggy address belongs to the object at ffff8880a683b000 [ 62.188248][ T26] which belongs to the cache kmalloc-1k of size 1024 [ 62.202299][ T26] The buggy address is located 484 bytes inside of [ 62.202299][ T26] 1024-byte region [ffff8880a683b000, ffff8880a683b400) [ 62.215835][ T26] The buggy address belongs to the page: [ 62.221465][ T26] page:ffffea00029a0ec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.230561][ T26] flags: 0xfffe0000000200(slab) [ 62.235414][ T26] raw: 00fffe0000000200 ffffea00025b84c8 ffffea0002546b48 ffff8880aa000c40 [ 62.244083][ T26] raw: 0000000000000000 ffff8880a683b000 0000000100000002 0000000000000000 [ 62.252655][ T26] page dumped because: kasan: bad access detected [ 62.259054][ T26] [ 62.261373][ T26] Memory state around the buggy address: [ 62.266996][ T26] ffff8880a683b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.275186][ T26] ffff8880a683b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.283267][ T26] >ffff8880a683b180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.291334][ T26] ^ [ 62.298560][ T26] ffff8880a683b200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.306634][ T26] ffff8880a683b280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.314799][ T26] ================================================================== [ 62.322850][ T26] Disabling lock debugging due to kernel taint [ 62.329055][ T26] Kernel panic - not syncing: panic_on_warn set ... [ 62.335651][ T26] CPU: 1 PID: 26 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.345362][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.355517][ T26] Workqueue: netns cleanup_net [ 62.360285][ T26] Call Trace: [ 62.363578][ T26] dump_stack+0x18f/0x20d [ 62.367928][ T26] ? afs_wake_up_async_call+0x670/0x770 [ 62.373471][ T26] ? afs_put_call+0xa40/0xa40 [ 62.378150][ T26] panic+0x2e3/0x75c [ 62.382052][ T26] ? __warn_printk+0xf3/0xf3 [ 62.386643][ T26] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.392799][ T26] ? trace_hardirqs_on+0x55/0x220 [ 62.397823][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.403500][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.409065][ T26] ? afs_put_call+0xa40/0xa40 [ 62.414005][ T26] end_report+0x4d/0x53 [ 62.418162][ T26] kasan_report.cold+0xd/0x37 [ 62.422832][ T26] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.428563][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.434116][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 62.439692][ T26] ? afs_close_socket+0x320/0x320 [ 62.444733][ T26] ? afs_put_call+0xa40/0xa40 [ 62.449547][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 62.454771][ T26] ? afs_put_call+0xa40/0xa40 [ 62.459638][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.466055][ T26] rxrpc_call_completed+0xca/0xf0 [ 62.471225][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 62.476737][ T26] ? lock_sock_nested+0x94/0x110 [ 62.481684][ T26] rxrpc_listen+0x147/0x360 [ 62.486202][ T26] afs_close_socket+0x95/0x320 [ 62.490960][ T26] ? afs_purge_servers+0x16d/0x300 [ 62.496076][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 62.501525][ T26] ? init_wait_var_entry+0x200/0x200 [ 62.506806][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.512552][ T26] ? check_preemption_disabled+0x38/0x220 [ 62.518263][ T26] afs_net_exit+0x1bc/0x310 [ 62.522748][ T26] ? afs_net_init+0xe30/0xe30 [ 62.527677][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 62.532777][ T26] cleanup_net+0x511/0xa50 [ 62.537307][ T26] ? unregister_pernet_device+0x70/0x70 [ 62.543064][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.549171][ T26] process_one_work+0x965/0x1690 [ 62.555275][ T26] ? lock_release+0x800/0x800 [ 62.559947][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.565427][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 62.570350][ T26] worker_thread+0x96/0xe10 [ 62.574851][ T26] ? process_one_work+0x1690/0x1690 [ 62.580126][ T26] kthread+0x3b5/0x4a0 [ 62.584194][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.589905][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.595606][ T26] ret_from_fork+0x1f/0x30 [ 62.604483][ T26] Kernel Offset: disabled [ 62.608810][ T26] Rebooting in 86400 seconds..