[ 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. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.15.208' (ECDSA) to the list of known hosts. 2020/06/15 02:07:53 fuzzer started 2020/06/15 02:07:53 connecting to host at 10.128.0.26:38195 2020/06/15 02:07:53 checking machine... 2020/06/15 02:07:53 checking revisions... 2020/06/15 02:07:53 testing simple program... syzkaller login: [ 60.282484][ T6836] IPVS: ftp: loaded support on port[0] = 21 2020/06/15 02:07:53 building call list... [ 60.612024][ T26] tipc: TX() has been purged, node left! [ 61.133974][ T26] ================================================================== [ 61.142376][ T26] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.150644][ T26] Write of size 1 at addr ffff888090a7c1e4 by task kworker/u4:2/26 [ 61.158521][ T26] [ 61.160872][ T26] CPU: 1 PID: 26 Comm: kworker/u4:2 Not tainted 5.8.0-rc1-next-20200615-syzkaller #0 [ 61.170499][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.180554][ T26] Workqueue: netns cleanup_net [ 61.185394][ T26] Call Trace: [ 61.188684][ T26] dump_stack+0x18f/0x20d [ 61.193026][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.198566][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.204110][ T26] ? afs_put_call+0xa40/0xa40 [ 61.208785][ T26] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.215814][ T26] ? vprintk_func+0x97/0x1a6 [ 61.220409][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.225956][ T26] kasan_report.cold+0x1f/0x37 [ 61.230722][ T26] ? rcu_read_lock_held_common+0x71/0xa0 [ 61.236347][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.241900][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 61.247273][ T26] ? afs_close_socket+0x320/0x320 [ 61.252298][ T26] ? afs_put_call+0xa40/0xa40 [ 61.256979][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 61.262097][ T26] ? afs_put_call+0xa40/0xa40 [ 61.266770][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.273186][ T26] rxrpc_call_completed+0xca/0xf0 [ 61.278218][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 61.283595][ T26] ? lock_sock_nested+0x94/0x110 [ 61.288539][ T26] rxrpc_listen+0x147/0x360 [ 61.293136][ T26] afs_close_socket+0x95/0x320 [ 61.297918][ T26] ? afs_purge_servers+0x16d/0x300 [ 61.303033][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 61.308585][ T26] ? init_wait_var_entry+0x200/0x200 [ 61.313874][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.319503][ T26] ? check_preemption_disabled+0x38/0x220 [ 61.325226][ T26] afs_net_exit+0x1bc/0x310 [ 61.329739][ T26] ? afs_net_init+0xe30/0xe30 [ 61.334588][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.339701][ T26] cleanup_net+0x511/0xa50 [ 61.344119][ T26] ? unregister_pernet_device+0x70/0x70 [ 61.349936][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.355939][ T26] process_one_work+0x965/0x1690 [ 61.360887][ T26] ? lock_release+0x800/0x800 [ 61.365582][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.370958][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 61.375918][ T26] worker_thread+0x96/0xe10 [ 61.380431][ T26] ? process_one_work+0x1690/0x1690 [ 61.385631][ T26] kthread+0x3b5/0x4a0 [ 61.389696][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.395432][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.401173][ T26] ret_from_fork+0x1f/0x30 [ 61.405597][ T26] [ 61.407917][ T26] Allocated by task 6836: [ 61.412335][ T26] save_stack+0x1b/0x40 [ 61.416486][ T26] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 61.422128][ T26] kmem_cache_alloc_trace+0x153/0x7d0 [ 61.427496][ T26] afs_alloc_call+0x55/0x630 [ 61.432083][ T26] afs_charge_preallocation+0xe9/0x2d0 [ 61.437536][ T26] afs_open_socket+0x292/0x360 [ 61.442294][ T26] afs_net_init+0xa6c/0xe30 [ 61.446789][ T26] ops_init+0xaf/0x420 [ 61.450858][ T26] setup_net+0x2de/0x860 [ 61.455104][ T26] copy_net_ns+0x293/0x590 [ 61.459536][ T26] create_new_namespaces+0x3fb/0xb30 [ 61.464825][ T26] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 61.470537][ T26] ksys_unshare+0x43d/0x8e0 [ 61.475052][ T26] __x64_sys_unshare+0x2d/0x40 [ 61.479817][ T26] do_syscall_64+0x60/0xe0 [ 61.484233][ T26] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 61.490123][ T26] [ 61.492446][ T26] Freed by task 26: [ 61.496269][ T26] save_stack+0x1b/0x40 [ 61.500419][ T26] __kasan_slab_free+0xf7/0x140 [ 61.505349][ T26] kfree+0x109/0x2b0 [ 61.509241][ T26] afs_put_call+0x585/0xa40 [ 61.513740][ T26] rxrpc_discard_prealloc+0x764/0xab0 [ 61.519121][ T26] rxrpc_listen+0x147/0x360 [ 61.523647][ T26] afs_close_socket+0x95/0x320 [ 61.528404][ T26] afs_net_exit+0x1bc/0x310 [ 61.532902][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.538009][ T26] cleanup_net+0x511/0xa50 [ 61.542438][ T26] process_one_work+0x965/0x1690 [ 61.547377][ T26] worker_thread+0x96/0xe10 [ 61.551960][ T26] kthread+0x3b5/0x4a0 [ 61.556029][ T26] ret_from_fork+0x1f/0x30 [ 61.560435][ T26] [ 61.562777][ T26] The buggy address belongs to the object at ffff888090a7c000 [ 61.562777][ T26] which belongs to the cache kmalloc-1k of size 1024 [ 61.576843][ T26] The buggy address is located 484 bytes inside of [ 61.576843][ T26] 1024-byte region [ffff888090a7c000, ffff888090a7c400) [ 61.590196][ T26] The buggy address belongs to the page: [ 61.595831][ T26] page:ffffea0002429f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 61.604943][ T26] flags: 0xfffe0000000200(slab) [ 61.609840][ T26] raw: 00fffe0000000200 ffffea0002401a88 ffffea0002a2d348 ffff8880aa000c40 [ 61.618536][ T26] raw: 0000000000000000 ffff888090a7c000 0000000100000002 0000000000000000 [ 61.627115][ T26] page dumped because: kasan: bad access detected [ 61.633612][ T26] [ 61.635945][ T26] Memory state around the buggy address: [ 61.641669][ T26] ffff888090a7c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.649819][ T26] ffff888090a7c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.657883][ T26] >ffff888090a7c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.665945][ T26] ^ [ 61.673144][ T26] ffff888090a7c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.681902][ T26] ffff888090a7c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.689961][ T26] ================================================================== [ 61.698019][ T26] Disabling lock debugging due to kernel taint [ 61.704223][ T26] Kernel panic - not syncing: panic_on_warn set ... [ 61.710823][ T26] CPU: 1 PID: 26 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc1-next-20200615-syzkaller #0 [ 61.721660][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.731888][ T26] Workqueue: netns cleanup_net [ 61.736710][ T26] Call Trace: [ 61.740000][ T26] dump_stack+0x18f/0x20d [ 61.744329][ T26] ? afs_wake_up_async_call+0x660/0x770 [ 61.749863][ T26] ? afs_put_call+0xa40/0xa40 [ 61.754550][ T26] panic+0x2e3/0x75c [ 61.758467][ T26] ? __warn_printk+0xf3/0xf3 [ 61.763063][ T26] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 61.769219][ T26] ? trace_hardirqs_on+0x55/0x220 [ 61.774239][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.779818][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.785378][ T26] ? afs_put_call+0xa40/0xa40 [ 61.790051][ T26] end_report+0x4d/0x53 [ 61.794202][ T26] kasan_report.cold+0xd/0x37 [ 61.798874][ T26] ? rcu_read_lock_held_common+0x71/0xa0 [ 61.804512][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.810049][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 61.815425][ T26] ? afs_close_socket+0x320/0x320 [ 61.820460][ T26] ? afs_put_call+0xa40/0xa40 [ 61.825127][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 61.830231][ T26] ? afs_put_call+0xa40/0xa40 [ 61.834900][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.841389][ T26] rxrpc_call_completed+0xca/0xf0 [ 61.846416][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 61.851780][ T26] ? lock_sock_nested+0x94/0x110 [ 61.856919][ T26] rxrpc_listen+0x147/0x360 [ 61.861533][ T26] afs_close_socket+0x95/0x320 [ 61.866291][ T26] ? afs_purge_servers+0x16d/0x300 [ 61.871441][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 61.878026][ T26] ? init_wait_var_entry+0x200/0x200 [ 61.883325][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.888953][ T26] ? check_preemption_disabled+0x38/0x220 [ 61.894679][ T26] afs_net_exit+0x1bc/0x310 [ 61.899182][ T26] ? afs_net_init+0xe30/0xe30 [ 61.903847][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.908955][ T26] cleanup_net+0x511/0xa50 [ 61.913395][ T26] ? unregister_pernet_device+0x70/0x70 [ 61.918935][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.925346][ T26] process_one_work+0x965/0x1690 [ 61.930282][ T26] ? lock_release+0x800/0x800 [ 61.935143][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.940507][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 61.945441][ T26] worker_thread+0x96/0xe10 [ 61.949956][ T26] ? process_one_work+0x1690/0x1690 [ 61.955145][ T26] kthread+0x3b5/0x4a0 [ 61.959204][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.964920][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.970644][ T26] ret_from_fork+0x1f/0x30 [ 61.976703][ T26] Kernel Offset: disabled [ 61.981553][ T26] Rebooting in 86400 seconds..