[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ 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 '10.128.10.12' (ECDSA) to the list of known hosts. 2020/06/18 06:14:45 fuzzer started 2020/06/18 06:14:46 connecting to host at 10.128.0.26:38715 2020/06/18 06:14:46 checking machine... 2020/06/18 06:14:46 checking revisions... 2020/06/18 06:14:46 testing simple program... syzkaller login: [ 60.027273][ T6828] IPVS: ftp: loaded support on port[0] = 21 2020/06/18 06:14:46 building call list... [ 60.413526][ T21] tipc: TX() has been purged, node left! [ 60.965628][ T21] ================================================================== [ 60.973886][ T21] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 60.981769][ T21] Write of size 1 at addr ffff88809f5579e4 by task kworker/u4:1/21 [ 60.989642][ T21] [ 60.991970][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.000194][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.010246][ T21] Workqueue: netns cleanup_net [ 61.014999][ T21] Call Trace: [ 61.018286][ T21] dump_stack+0x18f/0x20d [ 61.022614][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.028152][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.033693][ T21] ? afs_put_call+0xa40/0xa40 [ 61.038368][ T21] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.045412][ T21] ? vprintk_func+0x97/0x1a6 [ 61.050016][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.055568][ T21] kasan_report.cold+0x1f/0x37 [ 61.060335][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.065961][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.071505][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 61.077045][ T21] ? afs_close_socket+0x320/0x320 [ 61.082065][ T21] ? afs_put_call+0xa40/0xa40 [ 61.086743][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 61.091856][ T21] ? afs_put_call+0xa40/0xa40 [ 61.097419][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.103837][ T21] rxrpc_call_completed+0xca/0xf0 [ 61.108865][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 61.114237][ T21] ? lock_sock_nested+0x94/0x110 [ 61.119177][ T21] rxrpc_listen+0x147/0x360 [ 61.123680][ T21] afs_close_socket+0x95/0x320 [ 61.128452][ T21] ? afs_purge_servers+0x16d/0x300 [ 61.133563][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 61.139022][ T21] ? init_wait_var_entry+0x200/0x200 [ 61.144313][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.149941][ T21] ? check_preemption_disabled+0x38/0x220 [ 61.155675][ T21] afs_net_exit+0x1bc/0x310 [ 61.160265][ T21] ? afs_net_init+0xe30/0xe30 [ 61.164940][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 61.170051][ T21] cleanup_net+0x511/0xa50 [ 61.174672][ T21] ? unregister_pernet_device+0x70/0x70 [ 61.180409][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.186395][ T21] process_one_work+0x965/0x1690 [ 61.192298][ T21] ? lock_release+0x800/0x800 [ 61.196972][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.202345][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 61.207291][ T21] worker_thread+0x96/0xe10 [ 61.211810][ T21] ? process_one_work+0x1690/0x1690 [ 61.217008][ T21] kthread+0x3b5/0x4a0 [ 61.221073][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.226790][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.232598][ T21] ret_from_fork+0x1f/0x30 [ 61.237024][ T21] [ 61.239352][ T21] Allocated by task 6828: [ 61.243788][ T21] save_stack+0x1b/0x40 [ 61.247983][ T21] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 61.253630][ T21] kmem_cache_alloc_trace+0x153/0x7d0 [ 61.259017][ T21] afs_alloc_call+0x55/0x630 [ 61.263636][ T21] afs_charge_preallocation+0xe9/0x2d0 [ 61.269370][ T21] afs_open_socket+0x292/0x360 [ 61.274130][ T21] afs_net_init+0xa6c/0xe30 [ 61.278719][ T21] ops_init+0xaf/0x420 [ 61.282781][ T21] setup_net+0x2de/0x860 [ 61.287020][ T21] copy_net_ns+0x293/0x590 [ 61.291443][ T21] create_new_namespaces+0x3fb/0xb30 [ 61.296730][ T21] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 61.302459][ T21] ksys_unshare+0x43d/0x8e0 [ 61.307061][ T21] __x64_sys_unshare+0x2d/0x40 [ 61.311839][ T21] do_syscall_64+0x60/0xe0 [ 61.316265][ T21] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 61.322249][ T21] [ 61.324565][ T21] Freed by task 21: [ 61.328475][ T21] save_stack+0x1b/0x40 [ 61.332717][ T21] __kasan_slab_free+0xf7/0x140 [ 61.337587][ T21] kfree+0x109/0x2b0 [ 61.341485][ T21] afs_put_call+0x585/0xa40 [ 61.345986][ T21] rxrpc_discard_prealloc+0x764/0xab0 [ 61.351964][ T21] rxrpc_listen+0x147/0x360 [ 61.356462][ T21] afs_close_socket+0x95/0x320 [ 61.361214][ T21] afs_net_exit+0x1bc/0x310 [ 61.365713][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 61.370817][ T21] cleanup_net+0x511/0xa50 [ 61.375236][ T21] process_one_work+0x965/0x1690 [ 61.380172][ T21] worker_thread+0x96/0xe10 [ 61.384674][ T21] kthread+0x3b5/0x4a0 [ 61.388741][ T21] ret_from_fork+0x1f/0x30 [ 61.393143][ T21] [ 61.395466][ T21] The buggy address belongs to the object at ffff88809f557800 [ 61.395466][ T21] which belongs to the cache kmalloc-1k of size 1024 [ 61.409514][ T21] The buggy address is located 484 bytes inside of [ 61.409514][ T21] 1024-byte region [ffff88809f557800, ffff88809f557c00) [ 61.422863][ T21] The buggy address belongs to the page: [ 61.428493][ T21] page:ffffea00027d55c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 61.437591][ T21] flags: 0xfffe0000000200(slab) [ 61.442445][ T21] raw: 00fffe0000000200 ffffea00027ad708 ffffea00027711c8 ffff8880aa000c40 [ 61.451030][ T21] raw: 0000000000000000 ffff88809f557000 0000000100000002 0000000000000000 [ 61.459602][ T21] page dumped because: kasan: bad access detected [ 61.466000][ T21] [ 61.468319][ T21] Memory state around the buggy address: [ 61.473974][ T21] ffff88809f557880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.482029][ T21] ffff88809f557900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.490085][ T21] >ffff88809f557980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.498134][ T21] ^ [ 61.505322][ T21] ffff88809f557a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.513380][ T21] ffff88809f557a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.521432][ T21] ================================================================== [ 61.529482][ T21] Disabling lock debugging due to kernel taint [ 61.535721][ T21] Kernel panic - not syncing: panic_on_warn set ... [ 61.542301][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 61.551931][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.561991][ T21] Workqueue: netns cleanup_net [ 61.566738][ T21] Call Trace: [ 61.570113][ T21] dump_stack+0x18f/0x20d [ 61.574437][ T21] ? afs_wake_up_async_call+0x670/0x770 [ 61.579970][ T21] ? afs_put_call+0xa40/0xa40 [ 61.584636][ T21] panic+0x2e3/0x75c [ 61.588552][ T21] ? __warn_printk+0xf3/0xf3 [ 61.593138][ T21] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 61.599288][ T21] ? trace_hardirqs_on+0x55/0x220 [ 61.604305][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.609836][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.615377][ T21] ? afs_put_call+0xa40/0xa40 [ 61.620066][ T21] end_report+0x4d/0x53 [ 61.624213][ T21] kasan_report.cold+0xd/0x37 [ 61.628884][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.634682][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.640222][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 61.645583][ T21] ? afs_close_socket+0x320/0x320 [ 61.650598][ T21] ? afs_put_call+0xa40/0xa40 [ 61.655271][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 61.660375][ T21] ? afs_put_call+0xa40/0xa40 [ 61.665049][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.671459][ T21] rxrpc_call_completed+0xca/0xf0 [ 61.676480][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 61.681847][ T21] ? lock_sock_nested+0x94/0x110 [ 61.686777][ T21] rxrpc_listen+0x147/0x360 [ 61.691273][ T21] afs_close_socket+0x95/0x320 [ 61.696030][ T21] ? afs_purge_servers+0x16d/0x300 [ 61.701133][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 61.706583][ T21] ? init_wait_var_entry+0x200/0x200 [ 61.711863][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.717488][ T21] ? check_preemption_disabled+0x38/0x220 [ 61.723199][ T21] afs_net_exit+0x1bc/0x310 [ 61.727781][ T21] ? afs_net_init+0xe30/0xe30 [ 61.732449][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 61.737562][ T21] cleanup_net+0x511/0xa50 [ 61.741976][ T21] ? unregister_pernet_device+0x70/0x70 [ 61.747521][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.753500][ T21] process_one_work+0x965/0x1690 [ 61.758434][ T21] ? lock_release+0x800/0x800 [ 61.763102][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.768465][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 61.773407][ T21] worker_thread+0x96/0xe10 [ 61.777923][ T21] ? process_one_work+0x1690/0x1690 [ 61.783647][ T21] kthread+0x3b5/0x4a0 [ 61.787709][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.793432][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.799145][ T21] ret_from_fork+0x1f/0x30 [ 61.805074][ T21] Kernel Offset: disabled [ 61.809502][ T21] Rebooting in 86400 seconds..