[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. Starting Load/Save RF Kill Switch Status... [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.29' (ECDSA) to the list of known hosts. 2020/06/26 00:31:32 fuzzer started 2020/06/26 00:31:33 connecting to host at 10.128.0.26:44813 2020/06/26 00:31:33 checking machine... 2020/06/26 00:31:33 checking revisions... 2020/06/26 00:31:33 testing simple program... syzkaller login: [ 62.058966][ T6823] IPVS: ftp: loaded support on port[0] = 21 2020/06/26 00:31:33 building call list... [ 62.398183][ T21] tipc: TX() has been purged, node left! [ 62.910289][ T21] ================================================================== [ 62.918772][ T21] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x430/0x4a0 [ 62.926959][ T21] Write of size 1 at addr ffff8880938241e4 by task kworker/u4:1/21 [ 62.935841][ T21] [ 62.938359][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 [ 62.946587][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.958469][ T21] Workqueue: netns cleanup_net [ 62.964018][ T21] Call Trace: [ 62.967307][ T21] dump_stack+0x18f/0x20d [ 62.971747][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.977374][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.982942][ T21] ? afs_put_call+0x440/0x440 [ 62.987619][ T21] print_address_description.constprop.0.cold+0xae/0x436 [ 62.995268][ T21] ? vprintk_func+0x97/0x1a6 [ 63.001020][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 63.006670][ T21] kasan_report.cold+0x1f/0x37 [ 63.011535][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 63.017081][ T21] afs_wake_up_async_call+0x430/0x4a0 [ 63.022545][ T21] ? afs_close_socket+0x320/0x320 [ 63.027577][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 63.033408][ T21] ? afs_put_call+0x440/0x440 [ 63.038090][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.044524][ T21] rxrpc_call_completed+0xd0/0xf0 [ 63.049567][ T21] rxrpc_discard_prealloc+0x777/0xab0 [ 63.055285][ T21] ? lock_sock_nested+0x94/0x110 [ 63.060306][ T21] rxrpc_listen+0x11c/0x330 [ 63.064814][ T21] afs_close_socket+0x95/0x320 [ 63.069584][ T21] ? afs_purge_servers+0x16d/0x300 [ 63.074781][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 63.080331][ T21] ? init_wait_var_entry+0x200/0x200 [ 63.085646][ T21] ? check_preemption_disabled+0x38/0x220 [ 63.091372][ T21] afs_net_exit+0x1bc/0x310 [ 63.095873][ T21] ? __bpf_trace_afs_cb_miss+0x100/0x100 [ 63.101503][ T21] ops_exit_list+0xb0/0x160 [ 63.106008][ T21] cleanup_net+0x4ea/0xa00 [ 63.110426][ T21] ? ops_free_list.part.0+0x3d0/0x3d0 [ 63.115801][ T21] ? check_preemption_disabled+0x38/0x220 [ 63.121529][ T21] process_one_work+0x94c/0x1670 [ 63.126539][ T21] ? lock_release+0x8d0/0x8d0 [ 63.131225][ T21] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 63.137106][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 63.142192][ T21] worker_thread+0x64c/0x1120 [ 63.147344][ T21] ? process_one_work+0x1670/0x1670 [ 63.152823][ T21] kthread+0x3b5/0x4a0 [ 63.157250][ T21] ? __kthread_bind_mask+0xc0/0xc0 [ 63.162453][ T21] ? __kthread_bind_mask+0xc0/0xc0 [ 63.167655][ T21] ret_from_fork+0x1f/0x30 [ 63.172211][ T21] [ 63.174543][ T21] Allocated by task 6823: [ 63.179846][ T21] save_stack+0x1b/0x40 [ 63.184350][ T21] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 63.190066][ T21] kmem_cache_alloc_trace+0x14f/0x2d0 [ 63.195432][ T21] afs_alloc_call+0x4f/0x360 [ 63.200207][ T21] afs_charge_preallocation+0xe9/0x2d0 [ 63.205669][ T21] afs_open_socket+0x294/0x360 [ 63.210430][ T21] afs_net_init+0xa6c/0xe30 [ 63.214930][ T21] ops_init+0xaf/0x470 [ 63.219167][ T21] setup_net+0x2d8/0x850 [ 63.223491][ T21] copy_net_ns+0x2cf/0x5e0 [ 63.228280][ T21] create_new_namespaces+0x3f6/0xb10 [ 63.233561][ T21] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 63.239186][ T21] ksys_unshare+0x36c/0x9a0 [ 63.244123][ T21] __x64_sys_unshare+0x2d/0x40 [ 63.249001][ T21] do_syscall_64+0x60/0xe0 [ 63.253854][ T21] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 63.260080][ T21] [ 63.262425][ T21] Freed by task 21: [ 63.266449][ T21] save_stack+0x1b/0x40 [ 63.270758][ T21] __kasan_slab_free+0xf5/0x140 [ 63.275966][ T21] kfree+0x103/0x2c0 [ 63.279916][ T21] afs_put_call+0x345/0x440 [ 63.284695][ T21] rxrpc_discard_prealloc+0x75a/0xab0 [ 63.290072][ T21] rxrpc_listen+0x11c/0x330 [ 63.294572][ T21] afs_close_socket+0x95/0x320 [ 63.300393][ T21] afs_net_exit+0x1bc/0x310 [ 63.304981][ T21] ops_exit_list+0xb0/0x160 [ 63.309486][ T21] cleanup_net+0x4ea/0xa00 [ 63.314899][ T21] process_one_work+0x94c/0x1670 [ 63.320463][ T21] worker_thread+0x64c/0x1120 [ 63.327153][ T21] kthread+0x3b5/0x4a0 [ 63.331749][ T21] ret_from_fork+0x1f/0x30 [ 63.336591][ T21] [ 63.339010][ T21] The buggy address belongs to the object at ffff888093824000 [ 63.339010][ T21] which belongs to the cache kmalloc-1k of size 1024 [ 63.356680][ T21] The buggy address is located 484 bytes inside of [ 63.356680][ T21] 1024-byte region [ffff888093824000, ffff888093824400) [ 63.371795][ T21] The buggy address belongs to the page: [ 63.380431][ T21] page:ffffea00024e0900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 63.390149][ T21] flags: 0xfffe0000000200(slab) [ 63.395998][ T21] raw: 00fffe0000000200 ffffea00027d41c8 ffffea00028a0388 ffff8880aa000c40 [ 63.405048][ T21] raw: 0000000000000000 ffff888093824000 0000000100000002 0000000000000000 [ 63.414330][ T21] page dumped because: kasan: bad access detected [ 63.420927][ T21] [ 63.423267][ T21] Memory state around the buggy address: [ 63.428994][ T21] ffff888093824080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.437491][ T21] ffff888093824100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.445741][ T21] >ffff888093824180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.455960][ T21] ^ [ 63.463348][ T21] ffff888093824200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.472388][ T21] ffff888093824280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.481395][ T21] ================================================================== [ 63.489677][ T21] Disabling lock debugging due to kernel taint [ 63.496488][ T21] Kernel panic - not syncing: panic_on_warn set ... [ 63.503444][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 63.514383][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.524980][ T21] Workqueue: netns cleanup_net [ 63.529907][ T21] Call Trace: [ 63.533332][ T21] dump_stack+0x18f/0x20d [ 63.537763][ T21] ? afs_wake_up_async_call+0x370/0x4a0 [ 63.543399][ T21] ? afs_put_call+0x440/0x440 [ 63.548088][ T21] panic+0x2e3/0x75c [ 63.552437][ T21] ? __warn_printk+0xf3/0xf3 [ 63.557060][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 63.562613][ T21] ? trace_hardirqs_on+0x55/0x220 [ 63.568004][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 63.573692][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 63.579260][ T21] ? afs_put_call+0x440/0x440 [ 63.584384][ T21] end_report+0x4d/0x53 [ 63.589294][ T21] kasan_report.cold+0xd/0x37 [ 63.593975][ T21] ? afs_wake_up_async_call+0x430/0x4a0 [ 63.599713][ T21] afs_wake_up_async_call+0x430/0x4a0 [ 63.605087][ T21] ? afs_close_socket+0x320/0x320 [ 63.610110][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 63.615269][ T21] ? afs_put_call+0x440/0x440 [ 63.619957][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.626919][ T21] rxrpc_call_completed+0xd0/0xf0 [ 63.632054][ T21] rxrpc_discard_prealloc+0x777/0xab0 [ 63.637436][ T21] ? lock_sock_nested+0x94/0x110 [ 63.643161][ T21] rxrpc_listen+0x11c/0x330 [ 63.648204][ T21] afs_close_socket+0x95/0x320 [ 63.653055][ T21] ? afs_purge_servers+0x16d/0x300 [ 63.658249][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 63.663797][ T21] ? init_wait_var_entry+0x200/0x200 [ 63.670760][ T21] ? check_preemption_disabled+0x38/0x220 [ 63.676783][ T21] afs_net_exit+0x1bc/0x310 [ 63.681411][ T21] ? __bpf_trace_afs_cb_miss+0x100/0x100 [ 63.687232][ T21] ops_exit_list+0xb0/0x160 [ 63.691830][ T21] cleanup_net+0x4ea/0xa00 [ 63.696368][ T21] ? ops_free_list.part.0+0x3d0/0x3d0 [ 63.701745][ T21] ? check_preemption_disabled+0x38/0x220 [ 63.707470][ T21] process_one_work+0x94c/0x1670 [ 63.712409][ T21] ? lock_release+0x8d0/0x8d0 [ 63.717519][ T21] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 63.723196][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 63.728221][ T21] worker_thread+0x64c/0x1120 [ 63.732952][ T21] ? process_one_work+0x1670/0x1670 [ 63.738176][ T21] kthread+0x3b5/0x4a0 [ 63.742247][ T21] ? __kthread_bind_mask+0xc0/0xc0 [ 63.747528][ T21] ? __kthread_bind_mask+0xc0/0xc0 [ 63.753103][ T21] ret_from_fork+0x1f/0x30 [ 63.759749][ T21] Kernel Offset: disabled [ 63.764550][ T21] Rebooting in 86400 seconds..