[ 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 '10.128.0.251' (ECDSA) to the list of known hosts. 2020/06/19 00:52:45 fuzzer started 2020/06/19 00:52:45 connecting to host at 10.128.0.26:34369 2020/06/19 00:52:45 checking machine... 2020/06/19 00:52:45 checking revisions... 2020/06/19 00:52:45 testing simple program... syzkaller login: [ 60.589871][ T6829] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 00:52:46 building call list... [ 60.897683][ T279] tipc: TX() has been purged, node left! [ 61.478789][ T279] ================================================================== [ 61.487060][ T279] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 61.494947][ T279] Write of size 1 at addr ffff8880937681e4 by task kworker/u4:4/279 [ 61.502992][ T279] [ 61.505323][ T279] CPU: 0 PID: 279 Comm: kworker/u4:4 Not tainted 5.8.0-rc1-syzkaller #0 [ 61.513644][ T279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.523711][ T279] Workqueue: netns cleanup_net [ 61.528463][ T279] Call Trace: [ 61.531758][ T279] dump_stack+0x18f/0x20d [ 61.536090][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.541631][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.547185][ T279] ? afs_put_call+0xa40/0xa40 [ 61.551883][ T279] print_address_description.constprop.0.cold+0xd3/0x413 [ 61.559269][ T279] ? vprintk_func+0x97/0x1a6 [ 61.563866][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.569728][ T279] kasan_report.cold+0x1f/0x37 [ 61.574610][ T279] ? rcu_read_lock_held_common+0x51/0xa0 [ 61.580245][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 61.585815][ T279] afs_wake_up_async_call+0x6aa/0x770 [ 61.591279][ T279] ? afs_close_socket+0x320/0x320 [ 61.596304][ T279] ? afs_put_call+0xa40/0xa40 [ 61.600984][ T279] rxrpc_notify_socket+0x1db/0x5d0 [ 61.606097][ T279] ? afs_put_call+0xa40/0xa40 [ 61.610778][ T279] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.617193][ T279] rxrpc_call_completed+0xca/0xf0 [ 61.622333][ T279] rxrpc_discard_prealloc+0x781/0xab0 [ 61.627726][ T279] ? lock_sock_nested+0x94/0x110 [ 61.632668][ T279] rxrpc_listen+0x147/0x360 [ 61.637177][ T279] afs_close_socket+0x95/0x320 [ 61.641939][ T279] ? afs_purge_servers+0x16d/0x300 [ 61.647053][ T279] ? afs_rx_discard_new_call+0x50/0x50 [ 61.652620][ T279] ? init_wait_var_entry+0x200/0x200 [ 61.657992][ T279] ? rcu_read_lock_held_common+0xa0/0xa0 [ 61.663626][ T279] ? check_preemption_disabled+0x38/0x220 [ 61.669606][ T279] afs_net_exit+0x1bc/0x310 [ 61.674112][ T279] ? afs_net_init+0xe30/0xe30 [ 61.678784][ T279] ops_exit_list.isra.0+0xa8/0x150 [ 61.683999][ T279] cleanup_net+0x511/0xa50 [ 61.688414][ T279] ? unregister_pernet_device+0x70/0x70 [ 61.693961][ T279] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.699952][ T279] process_one_work+0x965/0x1690 [ 61.704916][ T279] ? lock_release+0x800/0x800 [ 61.709596][ T279] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.714973][ T279] ? rwlock_bug.part.0+0x90/0x90 [ 61.719918][ T279] worker_thread+0x96/0xe10 [ 61.724569][ T279] ? process_one_work+0x1690/0x1690 [ 61.729951][ T279] kthread+0x3b5/0x4a0 [ 61.734018][ T279] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.739736][ T279] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.745546][ T279] ret_from_fork+0x1f/0x30 [ 61.749969][ T279] [ 61.752291][ T279] Allocated by task 6829: [ 61.756618][ T279] save_stack+0x1b/0x40 [ 61.760767][ T279] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 61.766392][ T279] kmem_cache_alloc_trace+0x153/0x7d0 [ 61.771755][ T279] afs_alloc_call+0x55/0x630 [ 61.776347][ T279] afs_charge_preallocation+0xe9/0x2d0 [ 61.781882][ T279] afs_open_socket+0x292/0x360 [ 61.786639][ T279] afs_net_init+0xa6c/0xe30 [ 61.791221][ T279] ops_init+0xaf/0x420 [ 61.795283][ T279] setup_net+0x2de/0x860 [ 61.799531][ T279] copy_net_ns+0x293/0x590 [ 61.803941][ T279] create_new_namespaces+0x3fb/0xb30 [ 61.809241][ T279] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 61.815589][ T279] ksys_unshare+0x43d/0x8e0 [ 61.820085][ T279] __x64_sys_unshare+0x2d/0x40 [ 61.824842][ T279] do_syscall_64+0x60/0xe0 [ 61.829255][ T279] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 61.835140][ T279] [ 61.837468][ T279] Freed by task 279: [ 61.841356][ T279] save_stack+0x1b/0x40 [ 61.845510][ T279] __kasan_slab_free+0xf7/0x140 [ 61.850354][ T279] kfree+0x109/0x2b0 [ 61.854243][ T279] afs_put_call+0x585/0xa40 [ 61.858745][ T279] rxrpc_discard_prealloc+0x764/0xab0 [ 61.864110][ T279] rxrpc_listen+0x147/0x360 [ 61.868608][ T279] afs_close_socket+0x95/0x320 [ 61.873796][ T279] afs_net_exit+0x1bc/0x310 [ 61.878638][ T279] ops_exit_list.isra.0+0xa8/0x150 [ 61.883742][ T279] cleanup_net+0x511/0xa50 [ 61.888249][ T279] process_one_work+0x965/0x1690 [ 61.893191][ T279] worker_thread+0x96/0xe10 [ 61.897695][ T279] kthread+0x3b5/0x4a0 [ 61.901772][ T279] ret_from_fork+0x1f/0x30 [ 61.906174][ T279] [ 61.908503][ T279] The buggy address belongs to the object at ffff888093768000 [ 61.908503][ T279] which belongs to the cache kmalloc-1k of size 1024 [ 61.922567][ T279] The buggy address is located 484 bytes inside of [ 61.922567][ T279] 1024-byte region [ffff888093768000, ffff888093768400) [ 61.935914][ T279] The buggy address belongs to the page: [ 61.941548][ T279] page:ffffea00024dda00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 61.950650][ T279] flags: 0xfffe0000000200(slab) [ 61.955590][ T279] raw: 00fffe0000000200 ffffea0002506108 ffffea00028e5888 ffff8880aa000c40 [ 61.964170][ T279] raw: 0000000000000000 ffff888093768000 0000000100000002 0000000000000000 [ 61.972740][ T279] page dumped because: kasan: bad access detected [ 61.979145][ T279] [ 61.981462][ T279] Memory state around the buggy address: [ 61.987089][ T279] ffff888093768080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.995256][ T279] ffff888093768100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.003324][ T279] >ffff888093768180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.011401][ T279] ^ [ 62.018618][ T279] ffff888093768200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.026701][ T279] ffff888093768280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.034769][ T279] ================================================================== [ 62.042839][ T279] Disabling lock debugging due to kernel taint [ 62.049047][ T279] Kernel panic - not syncing: panic_on_warn set ... [ 62.055635][ T279] CPU: 0 PID: 279 Comm: kworker/u4:4 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.065585][ T279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.075660][ T279] Workqueue: netns cleanup_net [ 62.080411][ T279] Call Trace: [ 62.083719][ T279] dump_stack+0x18f/0x20d [ 62.088120][ T279] ? afs_wake_up_async_call+0x680/0x770 [ 62.093751][ T279] ? afs_put_call+0xa40/0xa40 [ 62.098424][ T279] panic+0x2e3/0x75c [ 62.102322][ T279] ? __warn_printk+0xf3/0xf3 [ 62.106929][ T279] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.113089][ T279] ? trace_hardirqs_on+0x55/0x220 [ 62.118204][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.123745][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.129282][ T279] ? afs_put_call+0xa40/0xa40 [ 62.133956][ T279] end_report+0x4d/0x53 [ 62.138108][ T279] kasan_report.cold+0xd/0x37 [ 62.142792][ T279] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.148419][ T279] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.153968][ T279] afs_wake_up_async_call+0x6aa/0x770 [ 62.159331][ T279] ? afs_close_socket+0x320/0x320 [ 62.164363][ T279] ? afs_put_call+0xa40/0xa40 [ 62.169034][ T279] rxrpc_notify_socket+0x1db/0x5d0 [ 62.174139][ T279] ? afs_put_call+0xa40/0xa40 [ 62.178813][ T279] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.185653][ T279] rxrpc_call_completed+0xca/0xf0 [ 62.190673][ T279] rxrpc_discard_prealloc+0x781/0xab0 [ 62.196052][ T279] ? lock_sock_nested+0x94/0x110 [ 62.200978][ T279] rxrpc_listen+0x147/0x360 [ 62.205646][ T279] afs_close_socket+0x95/0x320 [ 62.210406][ T279] ? afs_purge_servers+0x16d/0x300 [ 62.215510][ T279] ? afs_rx_discard_new_call+0x50/0x50 [ 62.221046][ T279] ? init_wait_var_entry+0x200/0x200 [ 62.226329][ T279] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.232107][ T279] ? check_preemption_disabled+0x38/0x220 [ 62.237818][ T279] afs_net_exit+0x1bc/0x310 [ 62.242312][ T279] ? afs_net_init+0xe30/0xe30 [ 62.247070][ T279] ops_exit_list.isra.0+0xa8/0x150 [ 62.252171][ T279] cleanup_net+0x511/0xa50 [ 62.256588][ T279] ? unregister_pernet_device+0x70/0x70 [ 62.262129][ T279] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.268102][ T279] process_one_work+0x965/0x1690 [ 62.273032][ T279] ? lock_release+0x800/0x800 [ 62.277700][ T279] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.283409][ T279] ? rwlock_bug.part.0+0x90/0x90 [ 62.289469][ T279] worker_thread+0x96/0xe10 [ 62.293969][ T279] ? process_one_work+0x1690/0x1690 [ 62.299858][ T279] kthread+0x3b5/0x4a0 [ 62.303920][ T279] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.309628][ T279] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.315342][ T279] ret_from_fork+0x1f/0x30 [ 62.321351][ T279] Kernel Offset: disabled [ 62.325677][ T279] Rebooting in 86400 seconds..