[ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started System Logging Service. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.85' (ECDSA) to the list of known hosts. 2020/07/03 19:54:36 fuzzer started 2020/07/03 19:54:37 connecting to host at 10.128.0.26:33099 2020/07/03 19:54:37 checking machine... 2020/07/03 19:54:37 checking revisions... 2020/07/03 19:54:37 testing simple program... syzkaller login: [ 59.642671][ T6801] IPVS: ftp: loaded support on port[0] = 21 2020/07/03 19:54:37 building call list... [ 59.981497][ T397] tipc: TX() has been purged, node left! [ 60.483395][ T397] ================================================================== [ 60.491712][ T397] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x430/0x4a0 [ 60.499595][ T397] Write of size 1 at addr ffff88809febc9e4 by task kworker/u4:4/397 [ 60.507557][ T397] [ 60.510006][ T397] CPU: 1 PID: 397 Comm: kworker/u4:4 Not tainted 5.8.0-rc1-syzkaller #0 [ 60.518316][ T397] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.528366][ T397] Workqueue: netns cleanup_net [ 60.533117][ T397] Call Trace: [ 60.536401][ T397] dump_stack+0x18f/0x20d [ 60.540731][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 60.546270][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 60.553803][ T397] ? afs_put_call+0x440/0x440 [ 60.558475][ T397] print_address_description.constprop.0.cold+0xae/0x436 [ 60.565498][ T397] ? vprintk_func+0x97/0x1a6 [ 60.570086][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 60.575630][ T397] kasan_report.cold+0x1f/0x37 [ 60.580390][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 60.585934][ T397] afs_wake_up_async_call+0x430/0x4a0 [ 60.591297][ T397] ? afs_close_socket+0x320/0x320 [ 60.596321][ T397] rxrpc_notify_socket+0x1db/0x5d0 [ 60.601433][ T397] ? afs_put_call+0x440/0x440 [ 60.606108][ T397] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 60.612521][ T397] rxrpc_call_completed+0xd0/0xf0 [ 60.617543][ T397] rxrpc_discard_prealloc+0x777/0xab0 [ 60.622914][ T397] ? lock_sock_nested+0x94/0x110 [ 60.627852][ T397] rxrpc_listen+0x11c/0x330 [ 60.632352][ T397] afs_close_socket+0x95/0x320 [ 60.637109][ T397] ? afs_purge_servers+0x16d/0x300 [ 60.642225][ T397] ? afs_rx_discard_new_call+0x50/0x50 [ 60.647693][ T397] ? init_wait_var_entry+0x200/0x200 [ 60.652980][ T397] ? check_preemption_disabled+0x38/0x220 [ 60.658697][ T397] afs_net_exit+0x1bc/0x310 [ 60.663193][ T397] ? __bpf_trace_afs_cb_miss+0x100/0x100 [ 60.668829][ T397] ops_exit_list+0xb0/0x160 [ 60.673331][ T397] cleanup_net+0x4ea/0xa00 [ 60.677740][ T397] ? __schedule+0x887/0x1eb0 [ 60.682328][ T397] ? ops_free_list.part.0+0x3d0/0x3d0 [ 60.687697][ T397] ? check_preemption_disabled+0x38/0x220 [ 60.693417][ T397] process_one_work+0x94c/0x1670 [ 60.698359][ T397] ? lock_release+0x8d0/0x8d0 [ 60.703032][ T397] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 60.708404][ T397] ? rwlock_bug.part.0+0x90/0x90 [ 60.713347][ T397] worker_thread+0x64c/0x1120 [ 60.718033][ T397] ? process_one_work+0x1670/0x1670 [ 60.723225][ T397] kthread+0x3b5/0x4a0 [ 60.727286][ T397] ? __kthread_bind_mask+0xc0/0xc0 [ 60.732390][ T397] ? __kthread_bind_mask+0xc0/0xc0 [ 60.737499][ T397] ret_from_fork+0x1f/0x30 [ 60.741922][ T397] [ 60.744242][ T397] Allocated by task 6801: [ 60.748564][ T397] save_stack+0x1b/0x40 [ 60.752718][ T397] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 60.758342][ T397] kmem_cache_alloc_trace+0x14f/0x2d0 [ 60.763705][ T397] afs_alloc_call+0x4f/0x360 [ 60.768286][ T397] afs_charge_preallocation+0xe9/0x2d0 [ 60.773737][ T397] afs_open_socket+0x294/0x360 [ 60.778492][ T397] afs_net_init+0xa6c/0xe30 [ 60.782985][ T397] ops_init+0xaf/0x470 [ 60.787045][ T397] setup_net+0x2d8/0x850 [ 60.791281][ T397] copy_net_ns+0x2cf/0x5e0 [ 60.795687][ T397] create_new_namespaces+0x3f6/0xb10 [ 60.800962][ T397] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 60.806590][ T397] ksys_unshare+0x36c/0x9a0 [ 60.811194][ T397] __x64_sys_unshare+0x2d/0x40 [ 60.815948][ T397] do_syscall_64+0x60/0xe0 [ 60.820359][ T397] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 60.826232][ T397] [ 60.828551][ T397] Freed by task 397: [ 60.832530][ T397] save_stack+0x1b/0x40 [ 60.836766][ T397] __kasan_slab_free+0xf5/0x140 [ 60.841611][ T397] kfree+0x103/0x2c0 [ 60.845498][ T397] afs_put_call+0x345/0x440 [ 60.850102][ T397] rxrpc_discard_prealloc+0x75a/0xab0 [ 60.855467][ T397] rxrpc_listen+0x11c/0x330 [ 60.859960][ T397] afs_close_socket+0x95/0x320 [ 60.864715][ T397] afs_net_exit+0x1bc/0x310 [ 60.869226][ T397] ops_exit_list+0xb0/0x160 [ 60.873727][ T397] cleanup_net+0x4ea/0xa00 [ 60.878141][ T397] process_one_work+0x94c/0x1670 [ 60.883077][ T397] worker_thread+0x64c/0x1120 [ 60.887751][ T397] kthread+0x3b5/0x4a0 [ 60.891815][ T397] ret_from_fork+0x1f/0x30 [ 60.896214][ T397] [ 60.898539][ T397] The buggy address belongs to the object at ffff88809febc800 [ 60.898539][ T397] which belongs to the cache kmalloc-1k of size 1024 [ 60.912595][ T397] The buggy address is located 484 bytes inside of [ 60.912595][ T397] 1024-byte region [ffff88809febc800, ffff88809febcc00) [ 60.925950][ T397] The buggy address belongs to the page: [ 60.931594][ T397] page:ffffea00027faf00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 60.940690][ T397] flags: 0xfffe0000000200(slab) [ 60.945541][ T397] raw: 00fffe0000000200 ffffea0002809548 ffffea00027f6108 ffff8880aa000c40 [ 60.954126][ T397] raw: 0000000000000000 ffff88809febc000 0000000100000002 0000000000000000 [ 60.962707][ T397] page dumped because: kasan: bad access detected [ 60.969111][ T397] [ 60.971435][ T397] Memory state around the buggy address: [ 60.977059][ T397] ffff88809febc880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.985202][ T397] ffff88809febc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.993255][ T397] >ffff88809febc980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.001305][ T397] ^ [ 61.008513][ T397] ffff88809febca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.016570][ T397] ffff88809febca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 61.025051][ T397] ================================================================== [ 61.033108][ T397] Disabling lock debugging due to kernel taint [ 61.039305][ T397] Kernel panic - not syncing: panic_on_warn set ... [ 61.046011][ T397] CPU: 1 PID: 397 Comm: kworker/u4:4 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 61.055710][ T397] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.065848][ T397] Workqueue: netns cleanup_net [ 61.070595][ T397] Call Trace: [ 61.073878][ T397] dump_stack+0x18f/0x20d [ 61.078199][ T397] ? afs_wake_up_async_call+0x3b0/0x4a0 [ 61.083732][ T397] ? afs_put_call+0x440/0x440 [ 61.088395][ T397] panic+0x2e3/0x75c [ 61.092278][ T397] ? __warn_printk+0xf3/0xf3 [ 61.096861][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 61.102400][ T397] ? trace_hardirqs_on+0x55/0x220 [ 61.107413][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 61.112945][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 61.118478][ T397] ? afs_put_call+0x440/0x440 [ 61.123148][ T397] end_report+0x4d/0x53 [ 61.127293][ T397] kasan_report.cold+0xd/0x37 [ 61.131961][ T397] ? afs_wake_up_async_call+0x430/0x4a0 [ 61.137494][ T397] afs_wake_up_async_call+0x430/0x4a0 [ 61.142856][ T397] ? afs_close_socket+0x320/0x320 [ 61.148479][ T397] rxrpc_notify_socket+0x1db/0x5d0 [ 61.153579][ T397] ? afs_put_call+0x440/0x440 [ 61.158246][ T397] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 61.164669][ T397] rxrpc_call_completed+0xd0/0xf0 [ 61.169683][ T397] rxrpc_discard_prealloc+0x777/0xab0 [ 61.175045][ T397] ? lock_sock_nested+0x94/0x110 [ 61.179973][ T397] rxrpc_listen+0x11c/0x330 [ 61.184469][ T397] afs_close_socket+0x95/0x320 [ 61.189219][ T397] ? afs_purge_servers+0x16d/0x300 [ 61.194317][ T397] ? afs_rx_discard_new_call+0x50/0x50 [ 61.199767][ T397] ? init_wait_var_entry+0x200/0x200 [ 61.205047][ T397] ? check_preemption_disabled+0x38/0x220 [ 61.210755][ T397] afs_net_exit+0x1bc/0x310 [ 61.215244][ T397] ? __bpf_trace_afs_cb_miss+0x100/0x100 [ 61.220865][ T397] ops_exit_list+0xb0/0x160 [ 61.225360][ T397] cleanup_net+0x4ea/0xa00 [ 61.229763][ T397] ? __schedule+0x887/0x1eb0 [ 61.234339][ T397] ? ops_free_list.part.0+0x3d0/0x3d0 [ 61.239715][ T397] ? check_preemption_disabled+0x38/0x220 [ 61.245424][ T397] process_one_work+0x94c/0x1670 [ 61.250354][ T397] ? lock_release+0x8d0/0x8d0 [ 61.255017][ T397] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 61.260379][ T397] ? rwlock_bug.part.0+0x90/0x90 [ 61.265310][ T397] worker_thread+0x64c/0x1120 [ 61.269981][ T397] ? process_one_work+0x1670/0x1670 [ 61.275166][ T397] kthread+0x3b5/0x4a0 [ 61.279221][ T397] ? __kthread_bind_mask+0xc0/0xc0 [ 61.284317][ T397] ? __kthread_bind_mask+0xc0/0xc0 [ 61.289417][ T397] ret_from_fork+0x1f/0x30 [ 61.295042][ T397] Kernel Offset: disabled [ 61.299355][ T397] Rebooting in 86400 seconds..