[ 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 '10.128.1.61' (ECDSA) to the list of known hosts. 2020/06/15 05:57:32 fuzzer started 2020/06/15 05:57:32 connecting to host at 10.128.0.26:37677 2020/06/15 05:57:32 checking machine... 2020/06/15 05:57:32 checking revisions... 2020/06/15 05:57:32 testing simple program... syzkaller login: [ 62.035527][ T6829] IPVS: ftp: loaded support on port[0] = 21 2020/06/15 05:57:33 building call list... [ 62.371529][ T278] tipc: TX() has been purged, node left! [ 62.884009][ T278] ================================================================== [ 62.892250][ T278] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 62.900138][ T278] Write of size 1 at addr ffff8880a45e79e4 by task kworker/u4:5/278 [ 62.908120][ T278] [ 62.910452][ T278] CPU: 0 PID: 278 Comm: kworker/u4:5 Not tainted 5.8.0-rc1-next-20200615-syzkaller #0 [ 62.920070][ T278] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.930124][ T278] Workqueue: netns cleanup_net [ 62.934965][ T278] Call Trace: [ 62.938260][ T278] dump_stack+0x18f/0x20d [ 62.942593][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.948132][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.953676][ T278] ? afs_put_call+0xa40/0xa40 [ 62.958353][ T278] print_address_description.constprop.0.cold+0xd3/0x413 [ 62.965379][ T278] ? vprintk_func+0x97/0x1a6 [ 62.969976][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.975520][ T278] kasan_report.cold+0x1f/0x37 [ 62.980285][ T278] ? rcu_read_lock_held_common+0x71/0xa0 [ 62.985912][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.991458][ T278] afs_wake_up_async_call+0x6aa/0x770 [ 62.996824][ T278] ? afs_close_socket+0x320/0x320 [ 63.001844][ T278] ? afs_put_call+0xa40/0xa40 [ 63.006518][ T278] rxrpc_notify_socket+0x1db/0x5d0 [ 63.011636][ T278] ? afs_put_call+0xa40/0xa40 [ 63.018479][ T278] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.024915][ T278] rxrpc_call_completed+0xca/0xf0 [ 63.029942][ T278] rxrpc_discard_prealloc+0x781/0xab0 [ 63.035319][ T278] ? lock_sock_nested+0x94/0x110 [ 63.040261][ T278] rxrpc_listen+0x147/0x360 [ 63.044777][ T278] afs_close_socket+0x95/0x320 [ 63.049539][ T278] ? afs_purge_servers+0x16d/0x300 [ 63.054673][ T278] ? afs_rx_discard_new_call+0x50/0x50 [ 63.060135][ T278] ? init_wait_var_entry+0x200/0x200 [ 63.065423][ T278] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.071054][ T278] ? check_preemption_disabled+0x38/0x220 [ 63.076784][ T278] afs_net_exit+0x1bc/0x310 [ 63.081313][ T278] ? afs_net_init+0xe30/0xe30 [ 63.086038][ T278] ops_exit_list.isra.0+0xa8/0x150 [ 63.091184][ T278] cleanup_net+0x511/0xa50 [ 63.095606][ T278] ? unregister_pernet_device+0x70/0x70 [ 63.101155][ T278] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.107145][ T278] process_one_work+0x965/0x1690 [ 63.112115][ T278] ? lock_release+0x800/0x800 [ 63.116792][ T278] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.122167][ T278] ? rwlock_bug.part.0+0x90/0x90 [ 63.127123][ T278] worker_thread+0x96/0xe10 [ 63.131643][ T278] ? process_one_work+0x1690/0x1690 [ 63.136841][ T278] kthread+0x3b5/0x4a0 [ 63.140924][ T278] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.146646][ T278] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.152983][ T278] ret_from_fork+0x1f/0x30 [ 63.157423][ T278] [ 63.159745][ T278] Allocated by task 6829: [ 63.164092][ T278] save_stack+0x1b/0x40 [ 63.168247][ T278] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 63.173875][ T278] kmem_cache_alloc_trace+0x153/0x7d0 [ 63.179241][ T278] afs_alloc_call+0x55/0x630 [ 63.183826][ T278] afs_charge_preallocation+0xe9/0x2d0 [ 63.189289][ T278] afs_open_socket+0x292/0x360 [ 63.194064][ T278] afs_net_init+0xa6c/0xe30 [ 63.198565][ T278] ops_init+0xaf/0x420 [ 63.202630][ T278] setup_net+0x2de/0x860 [ 63.208106][ T278] copy_net_ns+0x293/0x590 [ 63.212522][ T278] create_new_namespaces+0x3fb/0xb30 [ 63.217807][ T278] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 63.223438][ T278] ksys_unshare+0x43d/0x8e0 [ 63.227961][ T278] __x64_sys_unshare+0x2d/0x40 [ 63.232720][ T278] do_syscall_64+0x60/0xe0 [ 63.237150][ T278] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 63.243030][ T278] [ 63.245355][ T278] Freed by task 278: [ 63.249528][ T278] save_stack+0x1b/0x40 [ 63.253681][ T278] __kasan_slab_free+0xf7/0x140 [ 63.258527][ T278] kfree+0x109/0x2b0 [ 63.262419][ T278] afs_put_call+0x585/0xa40 [ 63.266919][ T278] rxrpc_discard_prealloc+0x764/0xab0 [ 63.272287][ T278] rxrpc_listen+0x147/0x360 [ 63.276784][ T278] afs_close_socket+0x95/0x320 [ 63.281556][ T278] afs_net_exit+0x1bc/0x310 [ 63.286064][ T278] ops_exit_list.isra.0+0xa8/0x150 [ 63.291177][ T278] cleanup_net+0x511/0xa50 [ 63.295592][ T278] process_one_work+0x965/0x1690 [ 63.300528][ T278] worker_thread+0x96/0xe10 [ 63.305045][ T278] kthread+0x3b5/0x4a0 [ 63.309134][ T278] ret_from_fork+0x1f/0x30 [ 63.313624][ T278] [ 63.315972][ T278] The buggy address belongs to the object at ffff8880a45e7800 [ 63.315972][ T278] which belongs to the cache kmalloc-1k of size 1024 [ 63.330017][ T278] The buggy address is located 484 bytes inside of [ 63.330017][ T278] 1024-byte region [ffff8880a45e7800, ffff8880a45e7c00) [ 63.343366][ T278] The buggy address belongs to the page: [ 63.349001][ T278] page:ffffea00029179c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 63.358101][ T278] flags: 0xfffe0000000200(slab) [ 63.362976][ T278] raw: 00fffe0000000200 ffffea00024e2448 ffffea00028bd388 ffff8880aa000c40 [ 63.371624][ T278] raw: 0000000000000000 ffff8880a45e7000 0000000100000002 0000000000000000 [ 63.380196][ T278] page dumped because: kasan: bad access detected [ 63.386602][ T278] [ 63.388921][ T278] Memory state around the buggy address: [ 63.394580][ T278] ffff8880a45e7880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.402639][ T278] ffff8880a45e7900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.410700][ T278] >ffff8880a45e7980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.418754][ T278] ^ [ 63.425971][ T278] ffff8880a45e7a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.434031][ T278] ffff8880a45e7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.442084][ T278] ================================================================== [ 63.450136][ T278] Disabling lock debugging due to kernel taint [ 63.456363][ T278] Kernel panic - not syncing: panic_on_warn set ... [ 63.462960][ T278] CPU: 0 PID: 278 Comm: kworker/u4:5 Tainted: G B 5.8.0-rc1-next-20200615-syzkaller #0 [ 63.473883][ T278] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.483952][ T278] Workqueue: netns cleanup_net [ 63.488710][ T278] Call Trace: [ 63.492004][ T278] dump_stack+0x18f/0x20d [ 63.496339][ T278] ? afs_wake_up_async_call+0x660/0x770 [ 63.501886][ T278] ? afs_put_call+0xa40/0xa40 [ 63.506613][ T278] panic+0x2e3/0x75c [ 63.510541][ T278] ? __warn_printk+0xf3/0xf3 [ 63.515156][ T278] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 63.521316][ T278] ? trace_hardirqs_on+0x55/0x220 [ 63.526357][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.532002][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.542248][ T278] ? afs_put_call+0xa40/0xa40 [ 63.546932][ T278] end_report+0x4d/0x53 [ 63.551157][ T278] kasan_report.cold+0xd/0x37 [ 63.555969][ T278] ? rcu_read_lock_held_common+0x71/0xa0 [ 63.561603][ T278] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.567313][ T278] afs_wake_up_async_call+0x6aa/0x770 [ 63.572786][ T278] ? afs_close_socket+0x320/0x320 [ 63.577798][ T278] ? afs_put_call+0xa40/0xa40 [ 63.582458][ T278] rxrpc_notify_socket+0x1db/0x5d0 [ 63.587568][ T278] ? afs_put_call+0xa40/0xa40 [ 63.592232][ T278] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.598626][ T278] rxrpc_call_completed+0xca/0xf0 [ 63.603903][ T278] rxrpc_discard_prealloc+0x781/0xab0 [ 63.609261][ T278] ? lock_sock_nested+0x94/0x110 [ 63.614198][ T278] rxrpc_listen+0x147/0x360 [ 63.618689][ T278] afs_close_socket+0x95/0x320 [ 63.623452][ T278] ? afs_purge_servers+0x16d/0x300 [ 63.628583][ T278] ? afs_rx_discard_new_call+0x50/0x50 [ 63.634162][ T278] ? init_wait_var_entry+0x200/0x200 [ 63.639445][ T278] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.645070][ T278] ? check_preemption_disabled+0x38/0x220 [ 63.650780][ T278] afs_net_exit+0x1bc/0x310 [ 63.655280][ T278] ? afs_net_init+0xe30/0xe30 [ 63.659946][ T278] ops_exit_list.isra.0+0xa8/0x150 [ 63.665077][ T278] cleanup_net+0x511/0xa50 [ 63.669500][ T278] ? unregister_pernet_device+0x70/0x70 [ 63.675032][ T278] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.681011][ T278] process_one_work+0x965/0x1690 [ 63.685960][ T278] ? lock_release+0x800/0x800 [ 63.690632][ T278] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.696007][ T278] ? rwlock_bug.part.0+0x90/0x90 [ 63.700959][ T278] worker_thread+0x96/0xe10 [ 63.705466][ T278] ? process_one_work+0x1690/0x1690 [ 63.710656][ T278] kthread+0x3b5/0x4a0 [ 63.714722][ T278] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.720439][ T278] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.726169][ T278] ret_from_fork+0x1f/0x30 [ 63.732135][ T278] Kernel Offset: disabled [ 63.736470][ T278] Rebooting in 86400 seconds..