[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.215' (ECDSA) to the list of known hosts. 2020/06/17 06:06:02 fuzzer started 2020/06/17 06:06:02 connecting to host at 10.128.0.26:35975 2020/06/17 06:06:02 checking machine... 2020/06/17 06:06:02 checking revisions... 2020/06/17 06:06:02 testing simple program... syzkaller login: [ 62.872309][ T6817] IPVS: ftp: loaded support on port[0] = 21 2020/06/17 06:06:03 building call list... [ 63.202944][ T21] tipc: TX() has been purged, node left! [ 63.765272][ T21] ================================================================== [ 63.774468][ T21] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 63.782354][ T21] Write of size 1 at addr ffff88809fea89e4 by task kworker/u4:1/21 [ 63.790232][ T21] [ 63.792566][ T21] CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 [ 63.800809][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.810871][ T21] Workqueue: netns cleanup_net [ 63.815635][ T21] Call Trace: [ 63.818928][ T21] dump_stack+0x18f/0x20d [ 63.823259][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.828916][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.834456][ T21] ? afs_put_call+0xa40/0xa40 [ 63.839133][ T21] print_address_description.constprop.0.cold+0xd3/0x413 [ 63.846188][ T21] ? vprintk_func+0x97/0x1a6 [ 63.850798][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.856342][ T21] kasan_report.cold+0x1f/0x37 [ 63.861109][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 63.866739][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.872287][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 63.877657][ T21] ? afs_close_socket+0x320/0x320 [ 63.882680][ T21] ? afs_put_call+0xa40/0xa40 [ 63.887375][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 63.892489][ T21] ? afs_put_call+0xa40/0xa40 [ 63.897166][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.903601][ T21] rxrpc_call_completed+0xca/0xf0 [ 63.908638][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 63.914019][ T21] ? lock_sock_nested+0x94/0x110 [ 63.918959][ T21] rxrpc_listen+0x147/0x360 [ 63.923463][ T21] afs_close_socket+0x95/0x320 [ 63.929178][ T21] ? afs_purge_servers+0x16d/0x300 [ 63.934289][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 63.939750][ T21] ? init_wait_var_entry+0x200/0x200 [ 63.945039][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.950692][ T21] ? check_preemption_disabled+0x38/0x220 [ 63.956425][ T21] afs_net_exit+0x1bc/0x310 [ 63.960932][ T21] ? afs_net_init+0xe30/0xe30 [ 63.965605][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 63.970721][ T21] cleanup_net+0x511/0xa50 [ 63.975147][ T21] ? unregister_pernet_device+0x70/0x70 [ 63.980696][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.986685][ T21] process_one_work+0x965/0x1690 [ 63.991637][ T21] ? lock_release+0x800/0x800 [ 63.996312][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 64.001687][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 64.006640][ T21] worker_thread+0x96/0xe10 [ 64.011158][ T21] ? process_one_work+0x1690/0x1690 [ 64.016359][ T21] kthread+0x3b5/0x4a0 [ 64.020427][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.026174][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.031911][ T21] ret_from_fork+0x1f/0x30 [ 64.036345][ T21] [ 64.038670][ T21] Allocated by task 6817: [ 64.043023][ T21] save_stack+0x1b/0x40 [ 64.047178][ T21] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 64.052805][ T21] kmem_cache_alloc_trace+0x153/0x7d0 [ 64.058171][ T21] afs_alloc_call+0x55/0x630 [ 64.062766][ T21] afs_charge_preallocation+0xe9/0x2d0 [ 64.068219][ T21] afs_open_socket+0x292/0x360 [ 64.072978][ T21] afs_net_init+0xa6c/0xe30 [ 64.077494][ T21] ops_init+0xaf/0x420 [ 64.081555][ T21] setup_net+0x2de/0x860 [ 64.085794][ T21] copy_net_ns+0x293/0x590 [ 64.090212][ T21] create_new_namespaces+0x3fb/0xb30 [ 64.095493][ T21] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 64.101132][ T21] ksys_unshare+0x43d/0x8e0 [ 64.105647][ T21] __x64_sys_unshare+0x2d/0x40 [ 64.110405][ T21] do_syscall_64+0x60/0xe0 [ 64.114819][ T21] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 64.120709][ T21] [ 64.123034][ T21] Freed by task 21: [ 64.126841][ T21] save_stack+0x1b/0x40 [ 64.130993][ T21] __kasan_slab_free+0xf7/0x140 [ 64.135842][ T21] kfree+0x109/0x2b0 [ 64.139741][ T21] afs_put_call+0x585/0xa40 [ 64.144243][ T21] rxrpc_discard_prealloc+0x764/0xab0 [ 64.149626][ T21] rxrpc_listen+0x147/0x360 [ 64.154133][ T21] afs_close_socket+0x95/0x320 [ 64.158894][ T21] afs_net_exit+0x1bc/0x310 [ 64.163389][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 64.168491][ T21] cleanup_net+0x511/0xa50 [ 64.172904][ T21] process_one_work+0x965/0x1690 [ 64.177838][ T21] worker_thread+0x96/0xe10 [ 64.182337][ T21] kthread+0x3b5/0x4a0 [ 64.186423][ T21] ret_from_fork+0x1f/0x30 [ 64.190838][ T21] [ 64.193169][ T21] The buggy address belongs to the object at ffff88809fea8800 [ 64.193169][ T21] which belongs to the cache kmalloc-1k of size 1024 [ 64.208003][ T21] The buggy address is located 484 bytes inside of [ 64.208003][ T21] 1024-byte region [ffff88809fea8800, ffff88809fea8c00) [ 64.221356][ T21] The buggy address belongs to the page: [ 64.226987][ T21] page:ffffea00027faa00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 64.236105][ T21] flags: 0xfffe0000000200(slab) [ 64.240962][ T21] raw: 00fffe0000000200 ffffea00029f6588 ffffea00027c7008 ffff8880aa000c40 [ 64.249545][ T21] raw: 0000000000000000 ffff88809fea8000 0000000100000002 0000000000000000 [ 64.258127][ T21] page dumped because: kasan: bad access detected [ 64.264536][ T21] [ 64.266866][ T21] Memory state around the buggy address: [ 64.272510][ T21] ffff88809fea8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.280573][ T21] ffff88809fea8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.288636][ T21] >ffff88809fea8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.296690][ T21] ^ [ 64.303880][ T21] ffff88809fea8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.311939][ T21] ffff88809fea8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.319992][ T21] ================================================================== [ 64.328044][ T21] Disabling lock debugging due to kernel taint [ 64.334247][ T21] Kernel panic - not syncing: panic_on_warn set ... [ 64.340843][ T21] CPU: 0 PID: 21 Comm: kworker/u4:1 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 64.350458][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.360526][ T21] Workqueue: netns cleanup_net [ 64.365285][ T21] Call Trace: [ 64.368579][ T21] dump_stack+0x18f/0x20d [ 64.372911][ T21] ? afs_wake_up_async_call+0x670/0x770 [ 64.378459][ T21] ? afs_put_call+0xa40/0xa40 [ 64.383141][ T21] panic+0x2e3/0x75c [ 64.387039][ T21] ? __warn_printk+0xf3/0xf3 [ 64.391632][ T21] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 64.397789][ T21] ? trace_hardirqs_on+0x55/0x220 [ 64.402817][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.408358][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.413884][ T21] ? afs_put_call+0xa40/0xa40 [ 64.418551][ T21] end_report+0x4d/0x53 [ 64.423314][ T21] kasan_report.cold+0xd/0x37 [ 64.427984][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 64.433619][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.439144][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 64.444500][ T21] ? afs_close_socket+0x320/0x320 [ 64.449518][ T21] ? afs_put_call+0xa40/0xa40 [ 64.454191][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 64.459296][ T21] ? afs_put_call+0xa40/0xa40 [ 64.463981][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 64.470389][ T21] rxrpc_call_completed+0xca/0xf0 [ 64.475414][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 64.480778][ T21] ? lock_sock_nested+0x94/0x110 [ 64.485796][ T21] rxrpc_listen+0x147/0x360 [ 64.490292][ T21] afs_close_socket+0x95/0x320 [ 64.495049][ T21] ? afs_purge_servers+0x16d/0x300 [ 64.500153][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 64.505696][ T21] ? init_wait_var_entry+0x200/0x200 [ 64.510976][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 64.516608][ T21] ? check_preemption_disabled+0x38/0x220 [ 64.522319][ T21] afs_net_exit+0x1bc/0x310 [ 64.527510][ T21] ? afs_net_init+0xe30/0xe30 [ 64.532178][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 64.537282][ T21] cleanup_net+0x511/0xa50 [ 64.541692][ T21] ? unregister_pernet_device+0x70/0x70 [ 64.547231][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 64.553208][ T21] process_one_work+0x965/0x1690 [ 64.558141][ T21] ? lock_release+0x800/0x800 [ 64.562809][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 64.568172][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 64.573106][ T21] worker_thread+0x96/0xe10 [ 64.577621][ T21] ? process_one_work+0x1690/0x1690 [ 64.582809][ T21] kthread+0x3b5/0x4a0 [ 64.586871][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.592582][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.598321][ T21] ret_from_fork+0x1f/0x30 [ 64.604107][ T21] Kernel Offset: disabled [ 64.608437][ T21] Rebooting in 86400 seconds..