[ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ 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 '10.128.0.191' (ECDSA) to the list of known hosts. 2020/06/19 03:29:37 fuzzer started 2020/06/19 03:29:37 connecting to host at 10.128.0.26:41667 2020/06/19 03:29:37 checking machine... 2020/06/19 03:29:37 checking revisions... 2020/06/19 03:29:37 testing simple program... syzkaller login: [ 61.616816][ T6886] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 03:29:37 building call list... [ 61.969298][ T319] tipc: TX() has been purged, node left! [ 62.461573][ T319] ================================================================== [ 62.469816][ T319] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 62.477879][ T319] Write of size 1 at addr ffff88809ff421e4 by task kworker/u4:6/319 [ 62.485845][ T319] [ 62.488279][ T319] CPU: 1 PID: 319 Comm: kworker/u4:6 Not tainted 5.8.0-rc1-syzkaller #0 [ 62.496598][ T319] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.506660][ T319] Workqueue: netns cleanup_net [ 62.511426][ T319] Call Trace: [ 62.514729][ T319] dump_stack+0x18f/0x20d [ 62.519084][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.524636][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.530184][ T319] ? afs_put_call+0xa40/0xa40 [ 62.534863][ T319] print_address_description.constprop.0.cold+0xd3/0x413 [ 62.541912][ T319] ? vprintk_func+0x97/0x1a6 [ 62.546510][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.552053][ T319] kasan_report.cold+0x1f/0x37 [ 62.556822][ T319] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.562454][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.568093][ T319] afs_wake_up_async_call+0x6aa/0x770 [ 62.573466][ T319] ? afs_close_socket+0x320/0x320 [ 62.578491][ T319] ? afs_put_call+0xa40/0xa40 [ 62.583177][ T319] rxrpc_notify_socket+0x1db/0x5d0 [ 62.588293][ T319] ? afs_put_call+0xa40/0xa40 [ 62.592971][ T319] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.599565][ T319] rxrpc_call_completed+0xca/0xf0 [ 62.604598][ T319] rxrpc_discard_prealloc+0x781/0xab0 [ 62.609975][ T319] ? lock_sock_nested+0x94/0x110 [ 62.614943][ T319] rxrpc_listen+0x147/0x360 [ 62.619450][ T319] afs_close_socket+0x95/0x320 [ 62.624301][ T319] ? afs_purge_servers+0x16d/0x300 [ 62.629432][ T319] ? afs_rx_discard_new_call+0x50/0x50 [ 62.635246][ T319] ? init_wait_var_entry+0x200/0x200 [ 62.640536][ T319] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.646170][ T319] ? check_preemption_disabled+0x38/0x220 [ 62.651893][ T319] afs_net_exit+0x1bc/0x310 [ 62.656403][ T319] ? afs_net_init+0xe30/0xe30 [ 62.663191][ T319] ops_exit_list.isra.0+0xa8/0x150 [ 62.668662][ T319] cleanup_net+0x511/0xa50 [ 62.673124][ T319] ? unregister_pernet_device+0x70/0x70 [ 62.678701][ T319] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.684710][ T319] process_one_work+0x965/0x1690 [ 62.689675][ T319] ? lock_release+0x800/0x800 [ 62.694704][ T319] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.700108][ T319] ? rwlock_bug.part.0+0x90/0x90 [ 62.705143][ T319] worker_thread+0x96/0xe10 [ 62.709661][ T319] ? process_one_work+0x1690/0x1690 [ 62.714958][ T319] kthread+0x3b5/0x4a0 [ 62.719026][ T319] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.724762][ T319] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.730509][ T319] ret_from_fork+0x1f/0x30 [ 62.734937][ T319] [ 62.737266][ T319] Allocated by task 6886: [ 62.741605][ T319] save_stack+0x1b/0x40 [ 62.745768][ T319] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.751405][ T319] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.756777][ T319] afs_alloc_call+0x55/0x630 [ 62.761372][ T319] afs_charge_preallocation+0xe9/0x2d0 [ 62.766939][ T319] afs_open_socket+0x292/0x360 [ 62.772145][ T319] afs_net_init+0xa6c/0xe30 [ 62.776643][ T319] ops_init+0xaf/0x420 [ 62.781227][ T319] setup_net+0x2de/0x860 [ 62.785470][ T319] copy_net_ns+0x293/0x590 [ 62.789883][ T319] create_new_namespaces+0x3fb/0xb30 [ 62.795176][ T319] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.801105][ T319] ksys_unshare+0x43d/0x8e0 [ 62.805960][ T319] __x64_sys_unshare+0x2d/0x40 [ 62.810721][ T319] do_syscall_64+0x60/0xe0 [ 62.815173][ T319] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.821140][ T319] [ 62.823471][ T319] Freed by task 319: [ 62.828059][ T319] save_stack+0x1b/0x40 [ 62.832221][ T319] __kasan_slab_free+0xf7/0x140 [ 62.837067][ T319] kfree+0x109/0x2b0 [ 62.840982][ T319] afs_put_call+0x585/0xa40 [ 62.845499][ T319] rxrpc_discard_prealloc+0x764/0xab0 [ 62.851063][ T319] rxrpc_listen+0x147/0x360 [ 62.855564][ T319] afs_close_socket+0x95/0x320 [ 62.860342][ T319] afs_net_exit+0x1bc/0x310 [ 62.864900][ T319] ops_exit_list.isra.0+0xa8/0x150 [ 62.870029][ T319] cleanup_net+0x511/0xa50 [ 62.874594][ T319] process_one_work+0x965/0x1690 [ 62.879542][ T319] worker_thread+0x96/0xe10 [ 62.884055][ T319] kthread+0x3b5/0x4a0 [ 62.888123][ T319] ret_from_fork+0x1f/0x30 [ 62.892525][ T319] [ 62.894854][ T319] The buggy address belongs to the object at ffff88809ff42000 [ 62.894854][ T319] which belongs to the cache kmalloc-1k of size 1024 [ 62.909358][ T319] The buggy address is located 484 bytes inside of [ 62.909358][ T319] 1024-byte region [ffff88809ff42000, ffff88809ff42400) [ 62.922729][ T319] The buggy address belongs to the page: [ 62.928390][ T319] page:ffffea00027fd080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.939422][ T319] flags: 0xfffe0000000200(slab) [ 62.944369][ T319] raw: 00fffe0000000200 ffffea00027e33c8 ffffea0002a22808 ffff8880aa000c40 [ 62.952959][ T319] raw: 0000000000000000 ffff88809ff42000 0000000100000002 0000000000000000 [ 62.961534][ T319] page dumped because: kasan: bad access detected [ 62.968456][ T319] [ 62.970786][ T319] Memory state around the buggy address: [ 62.976547][ T319] ffff88809ff42080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.984714][ T319] ffff88809ff42100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.993146][ T319] >ffff88809ff42180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.001218][ T319] ^ [ 63.009024][ T319] ffff88809ff42200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.017088][ T319] ffff88809ff42280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 63.025143][ T319] ================================================================== [ 63.033218][ T319] Disabling lock debugging due to kernel taint [ 63.039512][ T319] Kernel panic - not syncing: panic_on_warn set ... [ 63.046095][ T319] CPU: 1 PID: 319 Comm: kworker/u4:6 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 63.055805][ T319] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.066385][ T319] Workqueue: netns cleanup_net [ 63.071138][ T319] Call Trace: [ 63.074599][ T319] dump_stack+0x18f/0x20d [ 63.078933][ T319] ? afs_wake_up_async_call+0x680/0x770 [ 63.084481][ T319] ? afs_put_call+0xa40/0xa40 [ 63.089160][ T319] panic+0x2e3/0x75c [ 63.093070][ T319] ? __warn_printk+0xf3/0xf3 [ 63.097655][ T319] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 63.103890][ T319] ? trace_hardirqs_on+0x55/0x220 [ 63.108910][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.114560][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.120096][ T319] ? afs_put_call+0xa40/0xa40 [ 63.124797][ T319] end_report+0x4d/0x53 [ 63.128947][ T319] kasan_report.cold+0xd/0x37 [ 63.133716][ T319] ? rcu_read_lock_held_common+0x51/0xa0 [ 63.139337][ T319] ? afs_wake_up_async_call+0x6aa/0x770 [ 63.144875][ T319] afs_wake_up_async_call+0x6aa/0x770 [ 63.150237][ T319] ? afs_close_socket+0x320/0x320 [ 63.155250][ T319] ? afs_put_call+0xa40/0xa40 [ 63.159920][ T319] rxrpc_notify_socket+0x1db/0x5d0 [ 63.165035][ T319] ? afs_put_call+0xa40/0xa40 [ 63.169719][ T319] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 63.176158][ T319] rxrpc_call_completed+0xca/0xf0 [ 63.181199][ T319] rxrpc_discard_prealloc+0x781/0xab0 [ 63.186564][ T319] ? lock_sock_nested+0x94/0x110 [ 63.191501][ T319] rxrpc_listen+0x147/0x360 [ 63.196020][ T319] afs_close_socket+0x95/0x320 [ 63.200780][ T319] ? afs_purge_servers+0x16d/0x300 [ 63.205969][ T319] ? afs_rx_discard_new_call+0x50/0x50 [ 63.211430][ T319] ? init_wait_var_entry+0x200/0x200 [ 63.216716][ T319] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.222340][ T319] ? check_preemption_disabled+0x38/0x220 [ 63.228050][ T319] afs_net_exit+0x1bc/0x310 [ 63.232631][ T319] ? afs_net_init+0xe30/0xe30 [ 63.237296][ T319] ops_exit_list.isra.0+0xa8/0x150 [ 63.242415][ T319] cleanup_net+0x511/0xa50 [ 63.246824][ T319] ? unregister_pernet_device+0x70/0x70 [ 63.252366][ T319] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.258341][ T319] process_one_work+0x965/0x1690 [ 63.263276][ T319] ? lock_release+0x800/0x800 [ 63.267945][ T319] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.273308][ T319] ? rwlock_bug.part.0+0x90/0x90 [ 63.278238][ T319] worker_thread+0x96/0xe10 [ 63.282744][ T319] ? process_one_work+0x1690/0x1690 [ 63.287962][ T319] kthread+0x3b5/0x4a0 [ 63.292458][ T319] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.298193][ T319] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.303905][ T319] ret_from_fork+0x1f/0x30 [ 63.309990][ T319] Kernel Offset: disabled [ 63.314467][ T319] Rebooting in 86400 seconds..