[ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty2. [ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.15.198' (ECDSA) to the list of known hosts. 2020/06/19 00:05:21 fuzzer started 2020/06/19 00:05:21 connecting to host at 10.128.0.26:33457 2020/06/19 00:05:21 checking machine... 2020/06/19 00:05:21 checking revisions... 2020/06/19 00:05:21 testing simple program... syzkaller login: [ 61.355159][ T6837] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 00:05:21 building call list... [ 61.689543][ T619] tipc: TX() has been purged, node left! [ 62.182726][ T619] ================================================================== [ 62.191051][ T619] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 62.198938][ T619] Write of size 1 at addr ffff8880a82819e4 by task kworker/u4:4/619 [ 62.206914][ T619] [ 62.209315][ T619] CPU: 1 PID: 619 Comm: kworker/u4:4 Not tainted 5.8.0-rc1-syzkaller #0 [ 62.217865][ T619] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.227923][ T619] Workqueue: netns cleanup_net [ 62.232678][ T619] Call Trace: [ 62.236001][ T619] dump_stack+0x18f/0x20d [ 62.240336][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.245905][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.251452][ T619] ? afs_put_call+0xa40/0xa40 [ 62.256132][ T619] print_address_description.constprop.0.cold+0xd3/0x413 [ 62.263170][ T619] ? vprintk_func+0x97/0x1a6 [ 62.267779][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.273338][ T619] kasan_report.cold+0x1f/0x37 [ 62.278130][ T619] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.284196][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.289775][ T619] afs_wake_up_async_call+0x6aa/0x770 [ 62.295148][ T619] ? afs_close_socket+0x320/0x320 [ 62.300697][ T619] ? afs_put_call+0xa40/0xa40 [ 62.305373][ T619] rxrpc_notify_socket+0x1db/0x5d0 [ 62.310490][ T619] ? afs_put_call+0xa40/0xa40 [ 62.315166][ T619] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.321583][ T619] rxrpc_call_completed+0xca/0xf0 [ 62.326787][ T619] rxrpc_discard_prealloc+0x781/0xab0 [ 62.332166][ T619] ? lock_sock_nested+0x94/0x110 [ 62.337112][ T619] rxrpc_listen+0x147/0x360 [ 62.341632][ T619] afs_close_socket+0x95/0x320 [ 62.346394][ T619] ? afs_purge_servers+0x16d/0x300 [ 62.351521][ T619] ? afs_rx_discard_new_call+0x50/0x50 [ 62.356983][ T619] ? init_wait_var_entry+0x200/0x200 [ 62.362426][ T619] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.368080][ T619] ? check_preemption_disabled+0x38/0x220 [ 62.373804][ T619] afs_net_exit+0x1bc/0x310 [ 62.378425][ T619] ? afs_net_init+0xe30/0xe30 [ 62.383101][ T619] ops_exit_list.isra.0+0xa8/0x150 [ 62.388307][ T619] cleanup_net+0x511/0xa50 [ 62.392758][ T619] ? unregister_pernet_device+0x70/0x70 [ 62.398312][ T619] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.405263][ T619] process_one_work+0x965/0x1690 [ 62.410334][ T619] ? lock_release+0x800/0x800 [ 62.415102][ T619] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.420508][ T619] ? rwlock_bug.part.0+0x90/0x90 [ 62.425458][ T619] worker_thread+0x96/0xe10 [ 62.429980][ T619] ? process_one_work+0x1690/0x1690 [ 62.435181][ T619] kthread+0x3b5/0x4a0 [ 62.439265][ T619] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.445121][ T619] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.450867][ T619] ret_from_fork+0x1f/0x30 [ 62.455296][ T619] [ 62.457625][ T619] Allocated by task 6837: [ 62.461961][ T619] save_stack+0x1b/0x40 [ 62.466135][ T619] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.472135][ T619] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.477508][ T619] afs_alloc_call+0x55/0x630 [ 62.482099][ T619] afs_charge_preallocation+0xe9/0x2d0 [ 62.487554][ T619] afs_open_socket+0x292/0x360 [ 62.492315][ T619] afs_net_init+0xa6c/0xe30 [ 62.496818][ T619] ops_init+0xaf/0x420 [ 62.500882][ T619] setup_net+0x2de/0x860 [ 62.505122][ T619] copy_net_ns+0x293/0x590 [ 62.509539][ T619] create_new_namespaces+0x3fb/0xb30 [ 62.514933][ T619] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.520576][ T619] ksys_unshare+0x43d/0x8e0 [ 62.525079][ T619] __x64_sys_unshare+0x2d/0x40 [ 62.529837][ T619] do_syscall_64+0x60/0xe0 [ 62.534251][ T619] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.540134][ T619] [ 62.542467][ T619] Freed by task 619: [ 62.546362][ T619] save_stack+0x1b/0x40 [ 62.550515][ T619] __kasan_slab_free+0xf7/0x140 [ 62.555362][ T619] kfree+0x109/0x2b0 [ 62.559256][ T619] afs_put_call+0x585/0xa40 [ 62.563760][ T619] rxrpc_discard_prealloc+0x764/0xab0 [ 62.569129][ T619] rxrpc_listen+0x147/0x360 [ 62.573630][ T619] afs_close_socket+0x95/0x320 [ 62.578391][ T619] afs_net_exit+0x1bc/0x310 [ 62.582898][ T619] ops_exit_list.isra.0+0xa8/0x150 [ 62.588017][ T619] cleanup_net+0x511/0xa50 [ 62.592693][ T619] process_one_work+0x965/0x1690 [ 62.597774][ T619] worker_thread+0x96/0xe10 [ 62.602283][ T619] kthread+0x3b5/0x4a0 [ 62.606357][ T619] ret_from_fork+0x1f/0x30 [ 62.610766][ T619] [ 62.613095][ T619] The buggy address belongs to the object at ffff8880a8281800 [ 62.613095][ T619] which belongs to the cache kmalloc-1k of size 1024 [ 62.627149][ T619] The buggy address is located 484 bytes inside of [ 62.627149][ T619] 1024-byte region [ffff8880a8281800, ffff8880a8281c00) [ 62.640508][ T619] The buggy address belongs to the page: [ 62.646423][ T619] page:ffffea0002a0a040 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.655523][ T619] flags: 0xfffe0000000200(slab) [ 62.660385][ T619] raw: 00fffe0000000200 ffffea00027acec8 ffffea00027c1008 ffff8880aa000c40 [ 62.668989][ T619] raw: 0000000000000000 ffff8880a8281000 0000000100000002 0000000000000000 [ 62.677565][ T619] page dumped because: kasan: bad access detected [ 62.683974][ T619] [ 62.686308][ T619] Memory state around the buggy address: [ 62.691938][ T619] ffff8880a8281880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.699998][ T619] ffff8880a8281900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.709018][ T619] >ffff8880a8281980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.717071][ T619] ^ [ 62.724296][ T619] ffff8880a8281a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.732797][ T619] ffff8880a8281a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.740935][ T619] ================================================================== [ 62.748988][ T619] Disabling lock debugging due to kernel taint [ 62.755194][ T619] Kernel panic - not syncing: panic_on_warn set ... [ 62.761778][ T619] CPU: 1 PID: 619 Comm: kworker/u4:4 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.771475][ T619] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.781523][ T619] Workqueue: netns cleanup_net [ 62.786270][ T619] Call Trace: [ 62.789605][ T619] dump_stack+0x18f/0x20d [ 62.793932][ T619] ? afs_wake_up_async_call+0x680/0x770 [ 62.799639][ T619] ? afs_put_call+0xa40/0xa40 [ 62.804311][ T619] panic+0x2e3/0x75c [ 62.808197][ T619] ? __warn_printk+0xf3/0xf3 [ 62.812783][ T619] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.818929][ T619] ? trace_hardirqs_on+0x55/0x220 [ 62.823946][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.829497][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.835037][ T619] ? afs_put_call+0xa40/0xa40 [ 62.839709][ T619] end_report+0x4d/0x53 [ 62.844120][ T619] kasan_report.cold+0xd/0x37 [ 62.848808][ T619] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.854449][ T619] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.859995][ T619] afs_wake_up_async_call+0x6aa/0x770 [ 62.865355][ T619] ? afs_close_socket+0x320/0x320 [ 62.870631][ T619] ? afs_put_call+0xa40/0xa40 [ 62.875306][ T619] rxrpc_notify_socket+0x1db/0x5d0 [ 62.880412][ T619] ? afs_put_call+0xa40/0xa40 [ 62.885120][ T619] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.891527][ T619] rxrpc_call_completed+0xca/0xf0 [ 62.896548][ T619] rxrpc_discard_prealloc+0x781/0xab0 [ 62.901914][ T619] ? lock_sock_nested+0x94/0x110 [ 62.906866][ T619] rxrpc_listen+0x147/0x360 [ 62.911366][ T619] afs_close_socket+0x95/0x320 [ 62.916131][ T619] ? afs_purge_servers+0x16d/0x300 [ 62.921253][ T619] ? afs_rx_discard_new_call+0x50/0x50 [ 62.926707][ T619] ? init_wait_var_entry+0x200/0x200 [ 62.931994][ T619] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.937627][ T619] ? check_preemption_disabled+0x38/0x220 [ 62.943347][ T619] afs_net_exit+0x1bc/0x310 [ 62.947852][ T619] ? afs_net_init+0xe30/0xe30 [ 62.952540][ T619] ops_exit_list.isra.0+0xa8/0x150 [ 62.957657][ T619] cleanup_net+0x511/0xa50 [ 62.962076][ T619] ? unregister_pernet_device+0x70/0x70 [ 62.967622][ T619] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.973610][ T619] process_one_work+0x965/0x1690 [ 62.978559][ T619] ? lock_release+0x800/0x800 [ 62.983238][ T619] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.988610][ T619] ? rwlock_bug.part.0+0x90/0x90 [ 62.993551][ T619] worker_thread+0x96/0xe10 [ 62.998066][ T619] ? process_one_work+0x1690/0x1690 [ 63.004310][ T619] kthread+0x3b5/0x4a0 [ 63.008399][ T619] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.014118][ T619] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.019839][ T619] ret_from_fork+0x1f/0x30 [ 63.025588][ T619] Kernel Offset: disabled [ 63.029904][ T619] Rebooting in 86400 seconds..