[ OK ] Started System Logging Service. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Started OpenBSD Secure Shell server. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.62' (ECDSA) to the list of known hosts. 2020/06/19 03:55:00 fuzzer started 2020/06/19 03:55:00 connecting to host at 10.128.0.26:44555 2020/06/19 03:55:00 checking machine... 2020/06/19 03:55:00 checking revisions... 2020/06/19 03:55:00 testing simple program... syzkaller login: [ 60.909903][ T6802] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 03:55:01 building call list... [ 61.241952][ T26] tipc: TX() has been purged, node left! [ 61.764169][ T26] ================================================================== [ 61.772437][ T26] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.780348][ T26] Write of size 1 at addr ffff8880a8b7c1e4 by task kworker/u4:2/26 [ 61.788219][ T26] [ 61.790548][ T26] CPU: 0 PID: 26 Comm: kworker/u4:2 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.798774][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.808826][ T26] Workqueue: netns cleanup_net [ 61.813579][ T26] Call Trace: [ 61.816878][ T26] dump_stack+0x18f/0x20d [ 61.821231][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.826786][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.832335][ T26] ? afs_put_call+0xa40/0xa40 [ 61.837018][ T26] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.844060][ T26] ? vprintk_func+0x97/0x1a6 [ 61.848667][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.854209][ T26] kasan_report.cold+0x1f/0x37 [ 61.858975][ T26] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.864601][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.870147][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 61.875512][ T26] ? afs_close_socket+0x320/0x320 [ 61.880974][ T26] ? afs_put_call+0xa40/0xa40 [ 61.885649][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 61.890783][ T26] ? afs_put_call+0xa40/0xa40 [ 61.895456][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.901884][ T26] rxrpc_call_completed+0xca/0xf0 [ 61.906912][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 61.912284][ T26] ? lock_sock_nested+0x94/0x110 [ 61.917313][ T26] rxrpc_listen+0x147/0x360 [ 61.921955][ T26] afs_close_socket+0x95/0x320 [ 61.926730][ T26] ? afs_purge_servers+0x16d/0x300 [ 61.931861][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 61.937332][ T26] ? init_wait_var_entry+0x200/0x200 [ 61.942644][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.948366][ T26] ? check_preemption_disabled+0x38/0x220 [ 61.954087][ T26] afs_net_exit+0x1bc/0x310 [ 61.958585][ T26] ? afs_net_init+0xe30/0xe30 [ 61.963256][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 61.968366][ T26] cleanup_net+0x511/0xa50 [ 61.972785][ T26] ? unregister_pernet_device+0x70/0x70 [ 61.978339][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.984330][ T26] process_one_work+0x965/0x1690 [ 61.989276][ T26] ? lock_release+0x800/0x800 [ 61.993956][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.999345][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 62.004290][ T26] worker_thread+0x96/0xe10 [ 62.008814][ T26] ? process_one_work+0x1690/0x1690 [ 62.014010][ T26] kthread+0x3b5/0x4a0 [ 62.018163][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.023875][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.029618][ T26] ret_from_fork+0x1f/0x30 [ 62.034043][ T26] [ 62.036366][ T26] Allocated by task 6802: [ 62.040712][ T26] save_stack+0x1b/0x40 [ 62.044862][ T26] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.050491][ T26] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.055859][ T26] afs_alloc_call+0x55/0x630 [ 62.060446][ T26] afs_charge_preallocation+0xe9/0x2d0 [ 62.065901][ T26] afs_open_socket+0x292/0x360 [ 62.070932][ T26] afs_net_init+0xa6c/0xe30 [ 62.075440][ T26] ops_init+0xaf/0x420 [ 62.079506][ T26] setup_net+0x2de/0x860 [ 62.083744][ T26] copy_net_ns+0x293/0x590 [ 62.088156][ T26] create_new_namespaces+0x3fb/0xb30 [ 62.093449][ T26] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.099081][ T26] ksys_unshare+0x43d/0x8e0 [ 62.103578][ T26] __ia32_sys_unshare+0x2c/0x40 [ 62.108424][ T26] do_syscall_32_irqs_on+0x3f/0x60 [ 62.113529][ T26] do_fast_syscall_32+0x7f/0x120 [ 62.118459][ T26] entry_SYSENTER_compat+0x6d/0x7c [ 62.123553][ T26] [ 62.125889][ T26] Freed by task 26: [ 62.129691][ T26] save_stack+0x1b/0x40 [ 62.133863][ T26] __kasan_slab_free+0xf7/0x140 [ 62.138713][ T26] kfree+0x109/0x2b0 [ 62.142610][ T26] afs_put_call+0x585/0xa40 [ 62.147128][ T26] rxrpc_discard_prealloc+0x764/0xab0 [ 62.152513][ T26] rxrpc_listen+0x147/0x360 [ 62.157048][ T26] afs_close_socket+0x95/0x320 [ 62.161815][ T26] afs_net_exit+0x1bc/0x310 [ 62.166317][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 62.171419][ T26] cleanup_net+0x511/0xa50 [ 62.175838][ T26] process_one_work+0x965/0x1690 [ 62.180766][ T26] worker_thread+0x96/0xe10 [ 62.185290][ T26] kthread+0x3b5/0x4a0 [ 62.189353][ T26] ret_from_fork+0x1f/0x30 [ 62.193751][ T26] [ 62.196074][ T26] The buggy address belongs to the object at ffff8880a8b7c000 [ 62.196074][ T26] which belongs to the cache kmalloc-1k of size 1024 [ 62.210120][ T26] The buggy address is located 484 bytes inside of [ 62.210120][ T26] 1024-byte region [ffff8880a8b7c000, ffff8880a8b7c400) [ 62.223639][ T26] The buggy address belongs to the page: [ 62.229287][ T26] page:ffffea0002a2df00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.238382][ T26] flags: 0xfffe0000000200(slab) [ 62.243233][ T26] raw: 00fffe0000000200 ffffea00029c2e08 ffffea00029e7088 ffff8880aa000c40 [ 62.252424][ T26] raw: 0000000000000000 ffff8880a8b7c000 0000000100000002 0000000000000000 [ 62.261008][ T26] page dumped because: kasan: bad access detected [ 62.267491][ T26] [ 62.269810][ T26] Memory state around the buggy address: [ 62.275436][ T26] ffff8880a8b7c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.283675][ T26] ffff8880a8b7c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.291731][ T26] >ffff8880a8b7c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.299779][ T26] ^ [ 62.306967][ T26] ffff8880a8b7c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.315021][ T26] ffff8880a8b7c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.323067][ T26] ================================================================== [ 62.331113][ T26] Disabling lock debugging due to kernel taint [ 62.337352][ T26] Kernel panic - not syncing: panic_on_warn set ... [ 62.343942][ T26] CPU: 0 PID: 26 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.353556][ T26] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.363624][ T26] Workqueue: netns cleanup_net [ 62.368384][ T26] Call Trace: [ 62.371676][ T26] dump_stack+0x18f/0x20d [ 62.376006][ T26] ? afs_wake_up_async_call+0x670/0x770 [ 62.381551][ T26] ? afs_put_call+0xa40/0xa40 [ 62.386223][ T26] panic+0x2e3/0x75c [ 62.390119][ T26] ? __warn_printk+0xf3/0xf3 [ 62.394719][ T26] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.400895][ T26] ? trace_hardirqs_on+0x55/0x220 [ 62.405914][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.411447][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.417089][ T26] ? afs_put_call+0xa40/0xa40 [ 62.421824][ T26] end_report+0x4d/0x53 [ 62.425980][ T26] kasan_report.cold+0xd/0x37 [ 62.430664][ T26] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.436283][ T26] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.441820][ T26] afs_wake_up_async_call+0x6aa/0x770 [ 62.447183][ T26] ? afs_close_socket+0x320/0x320 [ 62.452192][ T26] ? afs_put_call+0xa40/0xa40 [ 62.456957][ T26] rxrpc_notify_socket+0x1db/0x5d0 [ 62.462136][ T26] ? afs_put_call+0xa40/0xa40 [ 62.466816][ T26] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.473240][ T26] rxrpc_call_completed+0xca/0xf0 [ 62.478275][ T26] rxrpc_discard_prealloc+0x781/0xab0 [ 62.483649][ T26] ? lock_sock_nested+0x94/0x110 [ 62.488583][ T26] rxrpc_listen+0x147/0x360 [ 62.493091][ T26] afs_close_socket+0x95/0x320 [ 62.497852][ T26] ? afs_purge_servers+0x16d/0x300 [ 62.502953][ T26] ? afs_rx_discard_new_call+0x50/0x50 [ 62.508420][ T26] ? init_wait_var_entry+0x200/0x200 [ 62.513732][ T26] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.519478][ T26] ? check_preemption_disabled+0x38/0x220 [ 62.525223][ T26] afs_net_exit+0x1bc/0x310 [ 62.529714][ T26] ? afs_net_init+0xe30/0xe30 [ 62.534386][ T26] ops_exit_list.isra.0+0xa8/0x150 [ 62.539493][ T26] cleanup_net+0x511/0xa50 [ 62.543899][ T26] ? unregister_pernet_device+0x70/0x70 [ 62.549426][ T26] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.555490][ T26] process_one_work+0x965/0x1690 [ 62.560425][ T26] ? lock_release+0x800/0x800 [ 62.565083][ T26] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.570552][ T26] ? rwlock_bug.part.0+0x90/0x90 [ 62.575491][ T26] worker_thread+0x96/0xe10 [ 62.579995][ T26] ? process_one_work+0x1690/0x1690 [ 62.585182][ T26] kthread+0x3b5/0x4a0 [ 62.589227][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.594929][ T26] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.600633][ T26] ret_from_fork+0x1f/0x30 [ 62.606293][ T26] Kernel Offset: disabled [ 62.610610][ T26] Rebooting in 86400 seconds..