[ 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 '10.128.1.55' (ECDSA) to the list of known hosts. 2020/06/19 00:52:48 fuzzer started 2020/06/19 00:52:48 connecting to host at 10.128.0.26:33769 2020/06/19 00:52:48 checking machine... 2020/06/19 00:52:48 checking revisions... 2020/06/19 00:52:48 testing simple program... syzkaller login: [ 61.337470][ T6944] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 00:52:48 building call list... [ 61.708857][ T21] tipc: TX() has been purged, node left! [ 62.261160][ T21] ================================================================== [ 62.269391][ T21] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 62.277276][ T21] Write of size 1 at addr ffff8880a4d071e4 by task kworker/u4:1/21 [ 62.285162][ T21] [ 62.287496][ T21] CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 [ 62.295731][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.305788][ T21] Workqueue: netns cleanup_net [ 62.310541][ T21] Call Trace: [ 62.313851][ T21] dump_stack+0x18f/0x20d [ 62.318193][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.323734][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.329273][ T21] ? afs_put_call+0xa40/0xa40 [ 62.334034][ T21] print_address_description.constprop.0.cold+0xd3/0x413 [ 62.341061][ T21] ? vprintk_func+0x97/0x1a6 [ 62.345654][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.351457][ T21] kasan_report.cold+0x1f/0x37 [ 62.356226][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.361850][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.367398][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 62.372765][ T21] ? afs_close_socket+0x320/0x320 [ 62.377789][ T21] ? afs_put_call+0xa40/0xa40 [ 62.382463][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 62.387671][ T21] ? afs_put_call+0xa40/0xa40 [ 62.392348][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.398775][ T21] rxrpc_call_completed+0xca/0xf0 [ 62.403802][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 62.409179][ T21] ? lock_sock_nested+0x94/0x110 [ 62.414120][ T21] rxrpc_listen+0x147/0x360 [ 62.419783][ T21] afs_close_socket+0x95/0x320 [ 62.424549][ T21] ? afs_purge_servers+0x16d/0x300 [ 62.429664][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 62.435145][ T21] ? init_wait_var_entry+0x200/0x200 [ 62.440451][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 62.446092][ T21] ? check_preemption_disabled+0x38/0x220 [ 62.451815][ T21] afs_net_exit+0x1bc/0x310 [ 62.456672][ T21] ? afs_net_init+0xe30/0xe30 [ 62.461351][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 62.466466][ T21] cleanup_net+0x511/0xa50 [ 62.470908][ T21] ? unregister_pernet_device+0x70/0x70 [ 62.476465][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 62.482459][ T21] process_one_work+0x965/0x1690 [ 62.487411][ T21] ? lock_release+0x800/0x800 [ 62.492090][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 62.497486][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 62.502441][ T21] worker_thread+0x96/0xe10 [ 62.506962][ T21] ? process_one_work+0x1690/0x1690 [ 62.512161][ T21] kthread+0x3b5/0x4a0 [ 62.516228][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.521945][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 62.527686][ T21] ret_from_fork+0x1f/0x30 [ 62.532129][ T21] [ 62.534738][ T21] Allocated by task 6944: [ 62.539084][ T21] save_stack+0x1b/0x40 [ 62.543238][ T21] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 62.548867][ T21] kmem_cache_alloc_trace+0x153/0x7d0 [ 62.554336][ T21] afs_alloc_call+0x55/0x630 [ 62.559015][ T21] afs_charge_preallocation+0xe9/0x2d0 [ 62.564574][ T21] afs_open_socket+0x292/0x360 [ 62.569332][ T21] afs_net_init+0xa6c/0xe30 [ 62.573830][ T21] ops_init+0xaf/0x420 [ 62.577918][ T21] setup_net+0x2de/0x860 [ 62.582154][ T21] copy_net_ns+0x293/0x590 [ 62.586566][ T21] create_new_namespaces+0x3fb/0xb30 [ 62.591857][ T21] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.597487][ T21] ksys_unshare+0x43d/0x8e0 [ 62.601986][ T21] __x64_sys_unshare+0x2d/0x40 [ 62.606743][ T21] do_syscall_64+0x60/0xe0 [ 62.611162][ T21] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.617175][ T21] [ 62.619495][ T21] Freed by task 21: [ 62.623318][ T21] save_stack+0x1b/0x40 [ 62.627472][ T21] __kasan_slab_free+0xf7/0x140 [ 62.632322][ T21] kfree+0x109/0x2b0 [ 62.636212][ T21] afs_put_call+0x585/0xa40 [ 62.640712][ T21] rxrpc_discard_prealloc+0x764/0xab0 [ 62.646086][ T21] rxrpc_listen+0x147/0x360 [ 62.650691][ T21] afs_close_socket+0x95/0x320 [ 62.655471][ T21] afs_net_exit+0x1bc/0x310 [ 62.659982][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 62.665103][ T21] cleanup_net+0x511/0xa50 [ 62.669654][ T21] process_one_work+0x965/0x1690 [ 62.674767][ T21] worker_thread+0x96/0xe10 [ 62.679265][ T21] kthread+0x3b5/0x4a0 [ 62.683337][ T21] ret_from_fork+0x1f/0x30 [ 62.687741][ T21] [ 62.690075][ T21] The buggy address belongs to the object at ffff8880a4d07000 [ 62.690075][ T21] which belongs to the cache kmalloc-1k of size 1024 [ 62.704340][ T21] The buggy address is located 484 bytes inside of [ 62.704340][ T21] 1024-byte region [ffff8880a4d07000, ffff8880a4d07400) [ 62.717708][ T21] The buggy address belongs to the page: [ 62.723351][ T21] page:ffffea00029341c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.732554][ T21] flags: 0xfffe0000000200(slab) [ 62.737417][ T21] raw: 00fffe0000000200 ffffea0002865688 ffffea0002368c88 ffff8880aa000c40 [ 62.746007][ T21] raw: 0000000000000000 ffff8880a4d07000 0000000100000002 0000000000000000 [ 62.754601][ T21] page dumped because: kasan: bad access detected [ 62.761001][ T21] [ 62.763349][ T21] Memory state around the buggy address: [ 62.768976][ T21] ffff8880a4d07080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.777044][ T21] ffff8880a4d07100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.785122][ T21] >ffff8880a4d07180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.793191][ T21] ^ [ 62.800380][ T21] ffff8880a4d07200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.808437][ T21] ffff8880a4d07280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.816495][ T21] ================================================================== [ 62.824551][ T21] Disabling lock debugging due to kernel taint [ 62.830744][ T21] Kernel panic - not syncing: panic_on_warn set ... [ 62.837337][ T21] CPU: 0 PID: 21 Comm: kworker/u4:1 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 62.846958][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.857240][ T21] Workqueue: netns cleanup_net [ 62.862003][ T21] Call Trace: [ 62.865291][ T21] dump_stack+0x18f/0x20d [ 62.869797][ T21] ? afs_wake_up_async_call+0x680/0x770 [ 62.875333][ T21] ? afs_put_call+0xa40/0xa40 [ 62.880007][ T21] panic+0x2e3/0x75c [ 62.883904][ T21] ? __warn_printk+0xf3/0xf3 [ 62.888491][ T21] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 62.894648][ T21] ? trace_hardirqs_on+0x55/0x220 [ 62.899675][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.905239][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.910797][ T21] ? afs_put_call+0xa40/0xa40 [ 62.915469][ T21] end_report+0x4d/0x53 [ 62.919620][ T21] kasan_report.cold+0xd/0x37 [ 62.924291][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 62.929913][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 62.935471][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 62.940837][ T21] ? afs_close_socket+0x320/0x320 [ 62.945855][ T21] ? afs_put_call+0xa40/0xa40 [ 62.950630][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 62.955760][ T21] ? afs_put_call+0xa40/0xa40 [ 62.960436][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.966874][ T21] rxrpc_call_completed+0xca/0xf0 [ 62.971895][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 62.977284][ T21] ? lock_sock_nested+0x94/0x110 [ 62.982218][ T21] rxrpc_listen+0x147/0x360 [ 62.986721][ T21] afs_close_socket+0x95/0x320 [ 62.991483][ T21] ? afs_purge_servers+0x16d/0x300 [ 62.996590][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 63.002052][ T21] ? init_wait_var_entry+0x200/0x200 [ 63.007331][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 63.012959][ T21] ? check_preemption_disabled+0x38/0x220 [ 63.018672][ T21] afs_net_exit+0x1bc/0x310 [ 63.023186][ T21] ? afs_net_init+0xe30/0xe30 [ 63.027852][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 63.032957][ T21] cleanup_net+0x511/0xa50 [ 63.037371][ T21] ? unregister_pernet_device+0x70/0x70 [ 63.042946][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.048923][ T21] process_one_work+0x965/0x1690 [ 63.053858][ T21] ? lock_release+0x800/0x800 [ 63.058527][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.063896][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 63.068848][ T21] worker_thread+0x96/0xe10 [ 63.073351][ T21] ? process_one_work+0x1690/0x1690 [ 63.078542][ T21] kthread+0x3b5/0x4a0 [ 63.082601][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.088314][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.094050][ T21] ret_from_fork+0x1f/0x30 [ 63.099905][ T21] Kernel Offset: disabled [ 63.104223][ T21] Rebooting in 86400 seconds..