[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.59' (ECDSA) to the list of known hosts. 2020/06/17 04:40:31 fuzzer started 2020/06/17 04:40:31 connecting to host at 10.128.0.26:44831 2020/06/17 04:40:31 checking machine... 2020/06/17 04:40:31 checking revisions... 2020/06/17 04:40:31 testing simple program... syzkaller login: [ 59.403324][ T6852] IPVS: ftp: loaded support on port[0] = 21 2020/06/17 04:40:31 building call list... [ 59.762879][ T87] tipc: TX() has been purged, node left! [ 60.334846][ T87] ================================================================== [ 60.343177][ T87] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 60.351063][ T87] Write of size 1 at addr ffff888091b4a9e4 by task kworker/u4:4/87 [ 60.358959][ T87] [ 60.361289][ T87] CPU: 0 PID: 87 Comm: kworker/u4:4 Not tainted 5.8.0-rc1-syzkaller #0 [ 60.369521][ T87] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.379583][ T87] Workqueue: netns cleanup_net [ 60.384340][ T87] Call Trace: [ 60.387633][ T87] dump_stack+0x18f/0x20d [ 60.391964][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 60.397595][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 60.403222][ T87] ? afs_put_call+0xa40/0xa40 [ 60.407899][ T87] print_address_description.constprop.0.cold+0xd3/0x413 [ 60.415883][ T87] ? vprintk_func+0x97/0x1a6 [ 60.420476][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 60.426018][ T87] kasan_report.cold+0x1f/0x37 [ 60.430788][ T87] ? rcu_read_lock_held_common+0x51/0xa0 [ 60.436419][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 60.441966][ T87] afs_wake_up_async_call+0x6aa/0x770 [ 60.447337][ T87] ? afs_close_socket+0x320/0x320 [ 60.452451][ T87] ? afs_put_call+0xa40/0xa40 [ 60.457128][ T87] rxrpc_notify_socket+0x1db/0x5d0 [ 60.462251][ T87] ? afs_put_call+0xa40/0xa40 [ 60.466929][ T87] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 60.473366][ T87] rxrpc_call_completed+0xca/0xf0 [ 60.478397][ T87] rxrpc_discard_prealloc+0x781/0xab0 [ 60.483771][ T87] ? lock_sock_nested+0x94/0x110 [ 60.488713][ T87] rxrpc_listen+0x147/0x360 [ 60.493217][ T87] afs_close_socket+0x95/0x320 [ 60.497984][ T87] ? afs_purge_servers+0x16d/0x300 [ 60.503122][ T87] ? afs_rx_discard_new_call+0x50/0x50 [ 60.508585][ T87] ? init_wait_var_entry+0x200/0x200 [ 60.514221][ T87] ? rcu_read_lock_held_common+0xa0/0xa0 [ 60.519852][ T87] ? check_preemption_disabled+0x38/0x220 [ 60.525584][ T87] afs_net_exit+0x1bc/0x310 [ 60.530083][ T87] ? afs_net_init+0xe30/0xe30 [ 60.534756][ T87] ops_exit_list.isra.0+0xa8/0x150 [ 60.539870][ T87] cleanup_net+0x511/0xa50 [ 60.544292][ T87] ? unregister_pernet_device+0x70/0x70 [ 60.549845][ T87] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 60.555833][ T87] process_one_work+0x965/0x1690 [ 60.560781][ T87] ? lock_release+0x800/0x800 [ 60.565463][ T87] ? pwq_dec_nr_in_flight+0x310/0x310 [ 60.570838][ T87] ? rwlock_bug.part.0+0x90/0x90 [ 60.575788][ T87] worker_thread+0x96/0xe10 [ 60.580310][ T87] ? process_one_work+0x1690/0x1690 [ 60.585517][ T87] kthread+0x3b5/0x4a0 [ 60.589595][ T87] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 60.595334][ T87] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 60.601083][ T87] ret_from_fork+0x1f/0x30 [ 60.605607][ T87] [ 60.607943][ T87] Allocated by task 6852: [ 60.612281][ T87] save_stack+0x1b/0x40 [ 60.616450][ T87] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 60.622098][ T87] kmem_cache_alloc_trace+0x153/0x7d0 [ 60.627482][ T87] afs_alloc_call+0x55/0x630 [ 60.632068][ T87] afs_charge_preallocation+0xe9/0x2d0 [ 60.637520][ T87] afs_open_socket+0x292/0x360 [ 60.642306][ T87] afs_net_init+0xa6c/0xe30 [ 60.646813][ T87] ops_init+0xaf/0x420 [ 60.650877][ T87] setup_net+0x2de/0x860 [ 60.655118][ T87] copy_net_ns+0x293/0x590 [ 60.659532][ T87] create_new_namespaces+0x3fb/0xb30 [ 60.664815][ T87] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 60.670444][ T87] ksys_unshare+0x43d/0x8e0 [ 60.674942][ T87] __x64_sys_unshare+0x2d/0x40 [ 60.679701][ T87] do_syscall_64+0x60/0xe0 [ 60.684115][ T87] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 60.689992][ T87] [ 60.692348][ T87] Freed by task 87: [ 60.696152][ T87] save_stack+0x1b/0x40 [ 60.700309][ T87] __kasan_slab_free+0xf7/0x140 [ 60.705159][ T87] kfree+0x109/0x2b0 [ 60.709055][ T87] afs_put_call+0x585/0xa40 [ 60.713563][ T87] rxrpc_discard_prealloc+0x764/0xab0 [ 60.718933][ T87] rxrpc_listen+0x147/0x360 [ 60.723438][ T87] afs_close_socket+0x95/0x320 [ 60.728285][ T87] afs_net_exit+0x1bc/0x310 [ 60.732790][ T87] ops_exit_list.isra.0+0xa8/0x150 [ 60.737915][ T87] cleanup_net+0x511/0xa50 [ 60.742337][ T87] process_one_work+0x965/0x1690 [ 60.747274][ T87] worker_thread+0x96/0xe10 [ 60.751783][ T87] kthread+0x3b5/0x4a0 [ 60.755866][ T87] ret_from_fork+0x1f/0x30 [ 60.760357][ T87] [ 60.762720][ T87] The buggy address belongs to the object at ffff888091b4a800 [ 60.762720][ T87] which belongs to the cache kmalloc-1k of size 1024 [ 60.776792][ T87] The buggy address is located 484 bytes inside of [ 60.776792][ T87] 1024-byte region [ffff888091b4a800, ffff888091b4ac00) [ 60.790336][ T87] The buggy address belongs to the page: [ 60.795969][ T87] page:ffffea000246d280 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 60.805070][ T87] flags: 0xfffe0000000200(slab) [ 60.809923][ T87] raw: 00fffe0000000200 ffffea00024e27c8 ffffea00028c5508 ffff8880aa000c40 [ 60.818510][ T87] raw: 0000000000000000 ffff888091b4a000 0000000100000002 0000000000000000 [ 60.827104][ T87] page dumped because: kasan: bad access detected [ 60.833502][ T87] [ 60.835822][ T87] Memory state around the buggy address: [ 60.841450][ T87] ffff888091b4a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.849512][ T87] ffff888091b4a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.857624][ T87] >ffff888091b4a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.865678][ T87] ^ [ 60.872867][ T87] ffff888091b4aa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.880924][ T87] ffff888091b4aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.888974][ T87] ================================================================== [ 60.897023][ T87] Disabling lock debugging due to kernel taint [ 60.903213][ T87] Kernel panic - not syncing: panic_on_warn set ... [ 60.909800][ T87] CPU: 0 PID: 87 Comm: kworker/u4:4 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 60.919415][ T87] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.929469][ T87] Workqueue: netns cleanup_net [ 60.934219][ T87] Call Trace: [ 60.937532][ T87] dump_stack+0x18f/0x20d [ 60.941857][ T87] ? afs_wake_up_async_call+0x670/0x770 [ 60.947392][ T87] ? afs_put_call+0xa40/0xa40 [ 60.952069][ T87] panic+0x2e3/0x75c [ 60.955960][ T87] ? __warn_printk+0xf3/0xf3 [ 60.960552][ T87] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 60.966805][ T87] ? trace_hardirqs_on+0x55/0x220 [ 60.971830][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 60.977371][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 60.982906][ T87] ? afs_put_call+0xa40/0xa40 [ 60.987579][ T87] end_report+0x4d/0x53 [ 60.991727][ T87] kasan_report.cold+0xd/0x37 [ 60.996400][ T87] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.002030][ T87] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.007575][ T87] afs_wake_up_async_call+0x6aa/0x770 [ 61.012937][ T87] ? afs_close_socket+0x320/0x320 [ 61.018232][ T87] ? afs_put_call+0xa40/0xa40 [ 61.022922][ T87] rxrpc_notify_socket+0x1db/0x5d0 [ 61.028025][ T87] ? afs_put_call+0xa40/0xa40 [ 61.032696][ T87] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.039105][ T87] rxrpc_call_completed+0xca/0xf0 [ 61.044128][ T87] rxrpc_discard_prealloc+0x781/0xab0 [ 61.049496][ T87] ? lock_sock_nested+0x94/0x110 [ 61.054456][ T87] rxrpc_listen+0x147/0x360 [ 61.058951][ T87] afs_close_socket+0x95/0x320 [ 61.063704][ T87] ? afs_purge_servers+0x16d/0x300 [ 61.068808][ T87] ? afs_rx_discard_new_call+0x50/0x50 [ 61.074261][ T87] ? init_wait_var_entry+0x200/0x200 [ 61.079713][ T87] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.085337][ T87] ? check_preemption_disabled+0x38/0x220 [ 61.091048][ T87] afs_net_exit+0x1bc/0x310 [ 61.095541][ T87] ? afs_net_init+0xe30/0xe30 [ 61.100210][ T87] ops_exit_list.isra.0+0xa8/0x150 [ 61.105313][ T87] cleanup_net+0x511/0xa50 [ 61.109722][ T87] ? unregister_pernet_device+0x70/0x70 [ 61.115270][ T87] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.121248][ T87] process_one_work+0x965/0x1690 [ 61.126185][ T87] ? lock_release+0x800/0x800 [ 61.130854][ T87] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.136217][ T87] ? rwlock_bug.part.0+0x90/0x90 [ 61.141150][ T87] worker_thread+0x96/0xe10 [ 61.145649][ T87] ? process_one_work+0x1690/0x1690 [ 61.150836][ T87] kthread+0x3b5/0x4a0 [ 61.154903][ T87] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.160611][ T87] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.166323][ T87] ret_from_fork+0x1f/0x30 [ 61.172308][ T87] Kernel Offset: disabled [ 61.176745][ T87] Rebooting in 86400 seconds..