[ 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 '10.128.10.55' (ECDSA) to the list of known hosts. 2020/06/18 08:33:59 fuzzer started 2020/06/18 08:33:59 connecting to host at 10.128.0.26:34053 2020/06/18 08:33:59 checking machine... 2020/06/18 08:33:59 checking revisions... 2020/06/18 08:33:59 testing simple program... syzkaller login: [ 60.473544][ T6798] IPVS: ftp: loaded support on port[0] = 21 2020/06/18 08:33:59 building call list... [ 60.797210][ T152] tipc: TX() has been purged, node left! [ 61.289383][ T152] ================================================================== [ 61.297651][ T152] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.305557][ T152] Write of size 1 at addr ffff8880a8f431e4 by task kworker/u4:4/152 [ 61.313520][ T152] [ 61.315966][ T152] CPU: 0 PID: 152 Comm: kworker/u4:4 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.324368][ T152] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.334636][ T152] Workqueue: netns cleanup_net [ 61.339398][ T152] Call Trace: [ 61.345824][ T152] dump_stack+0x18f/0x20d [ 61.350163][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.355706][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.361246][ T152] ? afs_put_call+0xa40/0xa40 [ 61.366042][ T152] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.373169][ T152] ? vprintk_func+0x97/0x1a6 [ 61.377971][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.383517][ T152] kasan_report.cold+0x1f/0x37 [ 61.388291][ T152] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.393938][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.399491][ T152] afs_wake_up_async_call+0x6aa/0x770 [ 61.404863][ T152] ? afs_close_socket+0x320/0x320 [ 61.409890][ T152] ? afs_put_call+0xa40/0xa40 [ 61.414564][ T152] rxrpc_notify_socket+0x1db/0x5d0 [ 61.419678][ T152] ? afs_put_call+0xa40/0xa40 [ 61.424786][ T152] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.431507][ T152] rxrpc_call_completed+0xca/0xf0 [ 61.436582][ T152] rxrpc_discard_prealloc+0x781/0xab0 [ 61.441971][ T152] ? lock_sock_nested+0x94/0x110 [ 61.446920][ T152] rxrpc_listen+0x147/0x360 [ 61.451431][ T152] afs_close_socket+0x95/0x320 [ 61.456197][ T152] ? afs_purge_servers+0x16d/0x300 [ 61.461423][ T152] ? afs_rx_discard_new_call+0x50/0x50 [ 61.466923][ T152] ? init_wait_var_entry+0x200/0x200 [ 61.472334][ T152] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.478004][ T152] ? check_preemption_disabled+0x38/0x220 [ 61.483815][ T152] afs_net_exit+0x1bc/0x310 [ 61.488429][ T152] ? afs_net_init+0xe30/0xe30 [ 61.493192][ T152] ops_exit_list.isra.0+0xa8/0x150 [ 61.498308][ T152] cleanup_net+0x511/0xa50 [ 61.502950][ T152] ? unregister_pernet_device+0x70/0x70 [ 61.508500][ T152] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.514491][ T152] process_one_work+0x965/0x1690 [ 61.519441][ T152] ? lock_release+0x800/0x800 [ 61.524324][ T152] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.529726][ T152] ? rwlock_bug.part.0+0x90/0x90 [ 61.534681][ T152] worker_thread+0x96/0xe10 [ 61.539200][ T152] ? process_one_work+0x1690/0x1690 [ 61.544404][ T152] kthread+0x3b5/0x4a0 [ 61.548583][ T152] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.554819][ T152] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.560629][ T152] ret_from_fork+0x1f/0x30 [ 61.565060][ T152] [ 61.567403][ T152] Allocated by task 6798: [ 61.571829][ T152] save_stack+0x1b/0x40 [ 61.576000][ T152] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 61.581799][ T152] kmem_cache_alloc_trace+0x153/0x7d0 [ 61.587253][ T152] afs_alloc_call+0x55/0x630 [ 61.591948][ T152] afs_charge_preallocation+0xe9/0x2d0 [ 61.597400][ T152] afs_open_socket+0x292/0x360 [ 61.602154][ T152] afs_net_init+0xa6c/0xe30 [ 61.606652][ T152] ops_init+0xaf/0x420 [ 61.610806][ T152] setup_net+0x2de/0x860 [ 61.615131][ T152] copy_net_ns+0x293/0x590 [ 61.619572][ T152] create_new_namespaces+0x3fb/0xb30 [ 61.625127][ T152] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 61.630757][ T152] ksys_unshare+0x43d/0x8e0 [ 61.635255][ T152] __x64_sys_unshare+0x2d/0x40 [ 61.640014][ T152] do_syscall_64+0x60/0xe0 [ 61.644435][ T152] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 61.650326][ T152] [ 61.652653][ T152] Freed by task 152: [ 61.656547][ T152] save_stack+0x1b/0x40 [ 61.660700][ T152] __kasan_slab_free+0xf7/0x140 [ 61.665545][ T152] kfree+0x109/0x2b0 [ 61.669436][ T152] afs_put_call+0x585/0xa40 [ 61.673938][ T152] rxrpc_discard_prealloc+0x764/0xab0 [ 61.679325][ T152] rxrpc_listen+0x147/0x360 [ 61.683827][ T152] afs_close_socket+0x95/0x320 [ 61.688592][ T152] afs_net_exit+0x1bc/0x310 [ 61.693092][ T152] ops_exit_list.isra.0+0xa8/0x150 [ 61.698379][ T152] cleanup_net+0x511/0xa50 [ 61.702931][ T152] process_one_work+0x965/0x1690 [ 61.707955][ T152] worker_thread+0x96/0xe10 [ 61.712730][ T152] kthread+0x3b5/0x4a0 [ 61.716796][ T152] ret_from_fork+0x1f/0x30 [ 61.721207][ T152] [ 61.723535][ T152] The buggy address belongs to the object at ffff8880a8f43000 [ 61.723535][ T152] which belongs to the cache kmalloc-1k of size 1024 [ 61.737681][ T152] The buggy address is located 484 bytes inside of [ 61.737681][ T152] 1024-byte region [ffff8880a8f43000, ffff8880a8f43400) [ 61.751213][ T152] The buggy address belongs to the page: [ 61.756876][ T152] page:ffffea0002a3d0c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 61.765979][ T152] flags: 0xfffe0000000200(slab) [ 61.770832][ T152] raw: 00fffe0000000200 ffffea00029d4248 ffffea0002a3b308 ffff8880aa000c40 [ 61.779423][ T152] raw: 0000000000000000 ffff8880a8f43000 0000000100000002 0000000000000000 [ 61.788016][ T152] page dumped because: kasan: bad access detected [ 61.794420][ T152] [ 61.796738][ T152] Memory state around the buggy address: [ 61.802902][ T152] ffff8880a8f43080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.811049][ T152] ffff8880a8f43100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.819987][ T152] >ffff8880a8f43180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.828060][ T152] ^ [ 61.835337][ T152] ffff8880a8f43200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.843407][ T152] ffff8880a8f43280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.851571][ T152] ================================================================== [ 61.859723][ T152] Disabling lock debugging due to kernel taint [ 61.865941][ T152] Kernel panic - not syncing: panic_on_warn set ... [ 61.872651][ T152] CPU: 0 PID: 152 Comm: kworker/u4:4 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 61.882353][ T152] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.892828][ T152] Workqueue: netns cleanup_net [ 61.900652][ T152] Call Trace: [ 61.903964][ T152] dump_stack+0x18f/0x20d [ 61.908307][ T152] ? afs_wake_up_async_call+0x670/0x770 [ 61.913864][ T152] ? afs_put_call+0xa40/0xa40 [ 61.918566][ T152] panic+0x2e3/0x75c [ 61.922476][ T152] ? __warn_printk+0xf3/0xf3 [ 61.927087][ T152] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 61.933257][ T152] ? trace_hardirqs_on+0x55/0x220 [ 61.939065][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.944607][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.950176][ T152] ? afs_put_call+0xa40/0xa40 [ 61.955840][ T152] end_report+0x4d/0x53 [ 61.960014][ T152] kasan_report.cold+0xd/0x37 [ 61.964777][ T152] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.970613][ T152] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.976521][ T152] afs_wake_up_async_call+0x6aa/0x770 [ 61.981972][ T152] ? afs_close_socket+0x320/0x320 [ 61.986990][ T152] ? afs_put_call+0xa40/0xa40 [ 61.991663][ T152] rxrpc_notify_socket+0x1db/0x5d0 [ 61.996857][ T152] ? afs_put_call+0xa40/0xa40 [ 62.001617][ T152] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.008553][ T152] rxrpc_call_completed+0xca/0xf0 [ 62.013669][ T152] rxrpc_discard_prealloc+0x781/0xab0 [ 62.019145][ T152] ? lock_sock_nested+0x94/0x110 [ 62.024088][ T152] rxrpc_listen+0x147/0x360 [ 62.028675][ T152] afs_close_socket+0x95/0x320 [ 62.034169][ T152] ? afs_purge_servers+0x16d/0x300 [ 62.039284][ T152] ? afs_rx_discard_new_call+0x50/0x50 [ 62.045085][ T152] ? init_wait_var_entry+0x200/0x200 [ 62.050503][ T152] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.056260][ T152] ? check_preemption_disabled+0x38/0x220 [ 62.062036][ T152] afs_net_exit+0x1bc/0x310 [ 62.068039][ T152] ? afs_net_init+0xe30/0xe30 [ 62.072713][ T152] ops_exit_list.isra.0+0xa8/0x150 [ 62.077825][ T152] cleanup_net+0x511/0xa50 [ 62.082237][ T152] ? unregister_pernet_device+0x70/0x70 [ 62.087780][ T152] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.093756][ T152] process_one_work+0x965/0x1690 [ 62.098796][ T152] ? lock_release+0x800/0x800 [ 62.103823][ T152] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.109222][ T152] ? rwlock_bug.part.0+0x90/0x90 [ 62.114162][ T152] worker_thread+0x96/0xe10 [ 62.118674][ T152] ? process_one_work+0x1690/0x1690 [ 62.123886][ T152] kthread+0x3b5/0x4a0 [ 62.128041][ T152] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.133841][ T152] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.139728][ T152] ret_from_fork+0x1f/0x30 [ 62.146100][ T152] Kernel Offset: disabled [ 62.150419][ T152] Rebooting in 86400 seconds..