[ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.6' (ECDSA) to the list of known hosts. 2020/06/19 05:40:46 fuzzer started 2020/06/19 05:40:46 connecting to host at 10.128.0.26:41433 2020/06/19 05:40:46 checking machine... 2020/06/19 05:40:46 checking revisions... 2020/06/19 05:40:46 testing simple program... syzkaller login: [ 62.288604][ T6927] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 05:40:46 building call list... [ 62.753698][ T7] tipc: TX() has been purged, node left! [ 63.265827][ T7] ================================================================== [ 63.274109][ T7] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 63.282010][ T7] Write of size 1 at addr ffff88809d42e1e4 by task kworker/u4:0/7 [ 63.289808][ T7] [ 63.292158][ T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0-rc1-syzkaller #0 [ 63.300413][ T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.310993][ T7] Workqueue: netns cleanup_net [ 63.315854][ T7] Call Trace: [ 63.319157][ T7] dump_stack+0x18f/0x20d [ 63.323492][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.329046][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.334587][ T7] ? afs_put_call+0xa40/0xa40 [ 63.339460][ T7] print_address_description.constprop.0.cold+0xd3/0x413 [ 63.346576][ T7] ? vprintk_func+0x97/0x1a6 [ 63.351380][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.358245][ T7] kasan_report.cold+0x1f/0x37 [ 63.363015][ T7] ? rcu_read_lock_held_common+0x51/0xa0 [ 63.368647][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.374193][ T7] afs_wake_up_async_call+0x6aa/0x770 [ 63.379560][ T7] ? afs_close_socket+0x320/0x320 [ 63.384604][ T7] ? afs_put_call+0xa40/0xa40 [ 63.389284][ T7] rxrpc_notify_socket+0x1db/0x5d0 [ 63.394407][ T7] ? afs_put_call+0xa40/0xa40 [ 63.399087][ T7] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.405518][ T7] rxrpc_call_completed+0xca/0xf0 [ 63.410586][ T7] rxrpc_discard_prealloc+0x781/0xab0 [ 63.416056][ T7] ? lock_sock_nested+0x94/0x110 [ 63.421029][ T7] rxrpc_listen+0x147/0x360 [ 63.425582][ T7] afs_close_socket+0x95/0x320 [ 63.430784][ T7] ? afs_purge_servers+0x16d/0x300 [ 63.435907][ T7] ? afs_rx_discard_new_call+0x50/0x50 [ 63.441420][ T7] ? init_wait_var_entry+0x200/0x200 [ 63.447252][ T7] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.452889][ T7] ? check_preemption_disabled+0x38/0x220 [ 63.458623][ T7] afs_net_exit+0x1bc/0x310 [ 63.463125][ T7] ? afs_net_init+0xe30/0xe30 [ 63.467890][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 63.473151][ T7] cleanup_net+0x511/0xa50 [ 63.477587][ T7] ? unregister_pernet_device+0x70/0x70 [ 63.483141][ T7] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.489146][ T7] process_one_work+0x965/0x1690 [ 63.494111][ T7] ? lock_release+0x800/0x800 [ 63.498795][ T7] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.504178][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 63.509151][ T7] worker_thread+0x96/0xe10 [ 63.514289][ T7] ? process_one_work+0x1690/0x1690 [ 63.519977][ T7] kthread+0x3b5/0x4a0 [ 63.524262][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.530164][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.535939][ T7] ret_from_fork+0x1f/0x30 [ 63.540453][ T7] [ 63.542776][ T7] Allocated by task 6927: [ 63.547105][ T7] save_stack+0x1b/0x40 [ 63.551259][ T7] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 63.557065][ T7] kmem_cache_alloc_trace+0x153/0x7d0 [ 63.563129][ T7] afs_alloc_call+0x55/0x630 [ 63.568113][ T7] afs_charge_preallocation+0xe9/0x2d0 [ 63.573567][ T7] afs_open_socket+0x292/0x360 [ 63.578414][ T7] afs_net_init+0xa6c/0xe30 [ 63.583106][ T7] ops_init+0xaf/0x420 [ 63.587431][ T7] setup_net+0x2de/0x860 [ 63.591759][ T7] copy_net_ns+0x293/0x590 [ 63.596220][ T7] create_new_namespaces+0x3fb/0xb30 [ 63.601508][ T7] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 63.607142][ T7] ksys_unshare+0x43d/0x8e0 [ 63.611642][ T7] __x64_sys_unshare+0x2d/0x40 [ 63.616407][ T7] do_syscall_64+0x60/0xe0 [ 63.621692][ T7] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 63.627657][ T7] [ 63.630500][ T7] Freed by task 7: [ 63.634935][ T7] save_stack+0x1b/0x40 [ 63.639443][ T7] __kasan_slab_free+0xf7/0x140 [ 63.644287][ T7] kfree+0x109/0x2b0 [ 63.648287][ T7] afs_put_call+0x585/0xa40 [ 63.652947][ T7] rxrpc_discard_prealloc+0x764/0xab0 [ 63.658335][ T7] rxrpc_listen+0x147/0x360 [ 63.662871][ T7] afs_close_socket+0x95/0x320 [ 63.667628][ T7] afs_net_exit+0x1bc/0x310 [ 63.672771][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 63.678129][ T7] cleanup_net+0x511/0xa50 [ 63.682557][ T7] process_one_work+0x965/0x1690 [ 63.687505][ T7] worker_thread+0x96/0xe10 [ 63.692179][ T7] kthread+0x3b5/0x4a0 [ 63.696275][ T7] ret_from_fork+0x1f/0x30 [ 63.700681][ T7] [ 63.703010][ T7] The buggy address belongs to the object at ffff88809d42e000 [ 63.703010][ T7] which belongs to the cache kmalloc-1k of size 1024 [ 63.717079][ T7] The buggy address is located 484 bytes inside of [ 63.717079][ T7] 1024-byte region [ffff88809d42e000, ffff88809d42e400) [ 63.730875][ T7] The buggy address belongs to the page: [ 63.737057][ T7] page:ffffea0002750b80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809d42e800 [ 63.747997][ T7] flags: 0xfffe0000000200(slab) [ 63.752945][ T7] raw: 00fffe0000000200 ffffea00023fd3c8 ffffea0002508d88 ffff8880aa000c40 [ 63.761645][ T7] raw: ffff88809d42e800 ffff88809d42e000 0000000100000001 0000000000000000 [ 63.770229][ T7] page dumped because: kasan: bad access detected [ 63.776651][ T7] [ 63.778981][ T7] Memory state around the buggy address: [ 63.784625][ T7] ffff88809d42e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.792834][ T7] ffff88809d42e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.800937][ T7] >ffff88809d42e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.809033][ T7] ^ [ 63.816254][ T7] ffff88809d42e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.824426][ T7] ffff88809d42e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.832761][ T7] ================================================================== [ 63.840882][ T7] Disabling lock debugging due to kernel taint [ 63.847282][ T7] Kernel panic - not syncing: panic_on_warn set ... [ 63.854589][ T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 63.864371][ T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.874521][ T7] Workqueue: netns cleanup_net [ 63.879364][ T7] Call Trace: [ 63.882673][ T7] dump_stack+0x18f/0x20d [ 63.887009][ T7] ? afs_wake_up_async_call+0x670/0x770 [ 63.892555][ T7] ? afs_put_call+0xa40/0xa40 [ 63.897253][ T7] panic+0x2e3/0x75c [ 63.901152][ T7] ? __warn_printk+0xf3/0xf3 [ 63.905742][ T7] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 63.912209][ T7] ? trace_hardirqs_on+0x55/0x220 [ 63.918174][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.923716][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.929262][ T7] ? afs_put_call+0xa40/0xa40 [ 63.933937][ T7] end_report+0x4d/0x53 [ 63.938106][ T7] kasan_report.cold+0xd/0x37 [ 63.942905][ T7] ? rcu_read_lock_held_common+0x51/0xa0 [ 63.948541][ T7] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.954090][ T7] afs_wake_up_async_call+0x6aa/0x770 [ 63.959474][ T7] ? afs_close_socket+0x320/0x320 [ 63.964590][ T7] ? afs_put_call+0xa40/0xa40 [ 63.969562][ T7] rxrpc_notify_socket+0x1db/0x5d0 [ 63.974947][ T7] ? afs_put_call+0xa40/0xa40 [ 63.979619][ T7] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.986600][ T7] rxrpc_call_completed+0xca/0xf0 [ 63.991630][ T7] rxrpc_discard_prealloc+0x781/0xab0 [ 63.997178][ T7] ? lock_sock_nested+0x94/0x110 [ 64.002202][ T7] rxrpc_listen+0x147/0x360 [ 64.006708][ T7] afs_close_socket+0x95/0x320 [ 64.011471][ T7] ? afs_purge_servers+0x16d/0x300 [ 64.016670][ T7] ? afs_rx_discard_new_call+0x50/0x50 [ 64.022125][ T7] ? init_wait_var_entry+0x200/0x200 [ 64.027434][ T7] ? rcu_read_lock_held_common+0xa0/0xa0 [ 64.033191][ T7] ? check_preemption_disabled+0x38/0x220 [ 64.038922][ T7] afs_net_exit+0x1bc/0x310 [ 64.043723][ T7] ? afs_net_init+0xe30/0xe30 [ 64.048401][ T7] ops_exit_list.isra.0+0xa8/0x150 [ 64.053523][ T7] cleanup_net+0x511/0xa50 [ 64.057935][ T7] ? unregister_pernet_device+0x70/0x70 [ 64.064275][ T7] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 64.070373][ T7] process_one_work+0x965/0x1690 [ 64.075332][ T7] ? lock_release+0x800/0x800 [ 64.080010][ T7] ? pwq_dec_nr_in_flight+0x310/0x310 [ 64.085380][ T7] ? rwlock_bug.part.0+0x90/0x90 [ 64.090324][ T7] worker_thread+0x96/0xe10 [ 64.094917][ T7] ? process_one_work+0x1690/0x1690 [ 64.100111][ T7] kthread+0x3b5/0x4a0 [ 64.104261][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.110062][ T7] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.115784][ T7] ret_from_fork+0x1f/0x30 [ 64.121592][ T7] Kernel Offset: disabled [ 64.125927][ T7] Rebooting in 86400 seconds..