[ 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 '10.128.1.12' (ECDSA) to the list of known hosts. 2020/06/17 22:29:57 fuzzer started 2020/06/17 22:29:57 connecting to host at 10.128.0.26:33457 2020/06/17 22:29:57 checking machine... 2020/06/17 22:29:57 checking revisions... 2020/06/17 22:29:57 testing simple program... syzkaller login: [ 63.176708][ T6835] IPVS: ftp: loaded support on port[0] = 21 2020/06/17 22:29:58 building call list... [ 63.543912][ T21] tipc: TX() has been purged, node left! [ 64.045874][ T21] ================================================================== [ 64.054114][ T21] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 64.062002][ T21] Write of size 1 at addr ffff8880968819e4 by task kworker/u4:1/21 [ 64.069880][ T21] [ 64.072214][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 [ 64.082446][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.092682][ T21] Workqueue: netns cleanup_net [ 64.097438][ T21] Call Trace: [ 64.100822][ T21] dump_stack+0x18f/0x20d [ 64.105157][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.110696][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.116242][ T21] ? afs_put_call+0xa40/0xa40 [ 64.120918][ T21] print_address_description.constprop.0.cold+0xd3/0x413 [ 64.127968][ T21] ? vprintk_func+0x97/0x1a6 [ 64.132561][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.138110][ T21] kasan_report.cold+0x1f/0x37 [ 64.142879][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 64.148511][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.154057][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 64.159427][ T21] ? afs_close_socket+0x320/0x320 [ 64.164455][ T21] ? afs_put_call+0xa40/0xa40 [ 64.169128][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 64.174241][ T21] ? afs_put_call+0xa40/0xa40 [ 64.178916][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 64.185333][ T21] rxrpc_call_completed+0xca/0xf0 [ 64.190363][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 64.195740][ T21] ? lock_sock_nested+0x94/0x110 [ 64.200679][ T21] rxrpc_listen+0x147/0x360 [ 64.205186][ T21] afs_close_socket+0x95/0x320 [ 64.209950][ T21] ? afs_purge_servers+0x16d/0x300 [ 64.215063][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 64.220542][ T21] ? init_wait_var_entry+0x200/0x200 [ 64.225829][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 64.231470][ T21] ? check_preemption_disabled+0x38/0x220 [ 64.237199][ T21] afs_net_exit+0x1bc/0x310 [ 64.241697][ T21] ? afs_net_init+0xe30/0xe30 [ 64.246457][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 64.251571][ T21] cleanup_net+0x511/0xa50 [ 64.255989][ T21] ? unregister_pernet_device+0x70/0x70 [ 64.261544][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 64.267531][ T21] process_one_work+0x965/0x1690 [ 64.272476][ T21] ? lock_release+0x800/0x800 [ 64.277152][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 64.282527][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 64.287475][ T21] worker_thread+0x96/0xe10 [ 64.292128][ T21] ? process_one_work+0x1690/0x1690 [ 64.297498][ T21] kthread+0x3b5/0x4a0 [ 64.301567][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.307541][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.313296][ T21] ret_from_fork+0x1f/0x30 [ 64.317738][ T21] [ 64.320165][ T21] Allocated by task 6835: [ 64.324511][ T21] save_stack+0x1b/0x40 [ 64.328663][ T21] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 64.334291][ T21] kmem_cache_alloc_trace+0x153/0x7d0 [ 64.339656][ T21] afs_alloc_call+0x55/0x630 [ 64.344244][ T21] afs_charge_preallocation+0xe9/0x2d0 [ 64.349797][ T21] afs_open_socket+0x292/0x360 [ 64.354563][ T21] afs_net_init+0xa6c/0xe30 [ 64.359077][ T21] ops_init+0xaf/0x420 [ 64.363145][ T21] setup_net+0x2de/0x860 [ 64.367382][ T21] copy_net_ns+0x293/0x590 [ 64.371819][ T21] create_new_namespaces+0x3fb/0xb30 [ 64.377113][ T21] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 64.382746][ T21] ksys_unshare+0x43d/0x8e0 [ 64.387251][ T21] __x64_sys_unshare+0x2d/0x40 [ 64.392011][ T21] do_syscall_64+0x60/0xe0 [ 64.396441][ T21] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 64.402326][ T21] [ 64.404649][ T21] Freed by task 21: [ 64.408458][ T21] save_stack+0x1b/0x40 [ 64.412619][ T21] __kasan_slab_free+0xf7/0x140 [ 64.417466][ T21] kfree+0x109/0x2b0 [ 64.421370][ T21] afs_put_call+0x585/0xa40 [ 64.425892][ T21] rxrpc_discard_prealloc+0x764/0xab0 [ 64.431277][ T21] rxrpc_listen+0x147/0x360 [ 64.435809][ T21] afs_close_socket+0x95/0x320 [ 64.440587][ T21] afs_net_exit+0x1bc/0x310 [ 64.445089][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 64.450282][ T21] cleanup_net+0x511/0xa50 [ 64.454697][ T21] process_one_work+0x965/0x1690 [ 64.459638][ T21] worker_thread+0x96/0xe10 [ 64.464135][ T21] kthread+0x3b5/0x4a0 [ 64.468220][ T21] ret_from_fork+0x1f/0x30 [ 64.472626][ T21] [ 64.474958][ T21] The buggy address belongs to the object at ffff888096881800 [ 64.474958][ T21] which belongs to the cache kmalloc-1k of size 1024 [ 64.489017][ T21] The buggy address is located 484 bytes inside of [ 64.489017][ T21] 1024-byte region [ffff888096881800, ffff888096881c00) [ 64.502366][ T21] The buggy address belongs to the page: [ 64.508017][ T21] page:ffffea00025a2040 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 64.517223][ T21] flags: 0xfffe0000000200(slab) [ 64.522087][ T21] raw: 00fffe0000000200 ffffea00025a2008 ffffea000239da08 ffff8880aa000c40 [ 64.530683][ T21] raw: 0000000000000000 ffff888096881000 0000000100000002 0000000000000000 [ 64.539269][ T21] page dumped because: kasan: bad access detected [ 64.545699][ T21] [ 64.548031][ T21] Memory state around the buggy address: [ 64.553736][ T21] ffff888096881880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.561793][ T21] ffff888096881900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.569849][ T21] >ffff888096881980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.577902][ T21] ^ [ 64.585096][ T21] ffff888096881a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.593157][ T21] ffff888096881a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 64.601206][ T21] ================================================================== [ 64.609270][ T21] Disabling lock debugging due to kernel taint [ 64.615461][ T21] Kernel panic - not syncing: panic_on_warn set ... [ 64.622057][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 64.631675][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.641735][ T21] Workqueue: netns cleanup_net [ 64.646492][ T21] Call Trace: [ 64.649798][ T21] dump_stack+0x18f/0x20d [ 64.655809][ T21] ? afs_wake_up_async_call+0x680/0x770 [ 64.661346][ T21] ? afs_put_call+0xa40/0xa40 [ 64.666276][ T21] panic+0x2e3/0x75c [ 64.670175][ T21] ? __warn_printk+0xf3/0xf3 [ 64.674850][ T21] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 64.681007][ T21] ? trace_hardirqs_on+0x55/0x220 [ 64.686245][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.691867][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.697405][ T21] ? afs_put_call+0xa40/0xa40 [ 64.702075][ T21] end_report+0x4d/0x53 [ 64.706318][ T21] kasan_report.cold+0xd/0x37 [ 64.711685][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 64.717337][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 64.722873][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 64.728250][ T21] ? afs_close_socket+0x320/0x320 [ 64.733283][ T21] ? afs_put_call+0xa40/0xa40 [ 64.737976][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 64.743538][ T21] ? afs_put_call+0xa40/0xa40 [ 64.748392][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 64.755263][ T21] rxrpc_call_completed+0xca/0xf0 [ 64.760286][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 64.765827][ T21] ? lock_sock_nested+0x94/0x110 [ 64.770770][ T21] rxrpc_listen+0x147/0x360 [ 64.775271][ T21] afs_close_socket+0x95/0x320 [ 64.780033][ T21] ? afs_purge_servers+0x16d/0x300 [ 64.785143][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 64.790596][ T21] ? init_wait_var_entry+0x200/0x200 [ 64.795876][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 64.801502][ T21] ? check_preemption_disabled+0x38/0x220 [ 64.807213][ T21] afs_net_exit+0x1bc/0x310 [ 64.811704][ T21] ? afs_net_init+0xe30/0xe30 [ 64.816370][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 64.821490][ T21] cleanup_net+0x511/0xa50 [ 64.825899][ T21] ? unregister_pernet_device+0x70/0x70 [ 64.831438][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 64.837418][ T21] process_one_work+0x965/0x1690 [ 64.842350][ T21] ? lock_release+0x800/0x800 [ 64.847020][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 64.852380][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 64.857315][ T21] worker_thread+0x96/0xe10 [ 64.861837][ T21] ? process_one_work+0x1690/0x1690 [ 64.867024][ T21] kthread+0x3b5/0x4a0 [ 64.871083][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.876799][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.882510][ T21] ret_from_fork+0x1f/0x30 [ 64.888225][ T21] Kernel Offset: disabled [ 64.892539][ T21] Rebooting in 86400 seconds..