[ 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 '10.128.0.4' (ECDSA) to the list of known hosts. 2020/06/25 23:52:17 fuzzer started 2020/06/25 23:52:18 connecting to host at 10.128.0.26:38461 2020/06/25 23:52:18 checking machine... 2020/06/25 23:52:18 checking revisions... 2020/06/25 23:52:18 testing simple program... syzkaller login: [ 61.274465][ T6805] IPVS: ftp: loaded support on port[0] = 21 2020/06/25 23:52:18 building call list... [ 61.647428][ T37] tipc: TX() has been purged, node left! [ 62.199751][ T37] ================================================================== [ 62.207990][ T37] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x430/0x4a0 [ 62.215873][ T37] Write of size 1 at addr ffff8880a251a1e4 by task kworker/u4:2/37 [ 62.223745][ T37] [ 62.226075][ T37] CPU: 1 PID: 37 Comm: kworker/u4:2 Not tainted 5.8.0-rc2-syzkaller #0 [ 62.234298][ T37] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.244438][ T37] Workqueue: netns cleanup_net [ 62.249188][ T37] Call Trace: [ 62.252475][ T37] dump_stack+0x18f/0x20d [ 62.256812][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.262350][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.267893][ T37] ? afs_put_call+0x440/0x440 [ 62.272573][ T37] print_address_description.constprop.0.cold+0xae/0x436 [ 62.279607][ T37] ? vprintk_func+0x97/0x1a6 [ 62.284196][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.289738][ T37] kasan_report.cold+0x1f/0x37 [ 62.294502][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.300135][ T37] afs_wake_up_async_call+0x430/0x4a0 [ 62.305499][ T37] ? afs_close_socket+0x320/0x320 [ 62.310523][ T37] rxrpc_notify_socket+0x1db/0x5d0 [ 62.315634][ T37] ? afs_put_call+0x440/0x440 [ 62.320310][ T37] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.326725][ T37] rxrpc_call_completed+0xd0/0xf0 [ 62.331747][ T37] rxrpc_discard_prealloc+0x777/0xab0 [ 62.337114][ T37] ? lock_sock_nested+0x94/0x110 [ 62.342065][ T37] rxrpc_listen+0x11c/0x330 [ 62.346573][ T37] afs_close_socket+0x95/0x320 [ 62.351333][ T37] ? afs_purge_servers+0x181/0x330 [ 62.356443][ T37] ? afs_rx_discard_new_call+0x50/0x50 [ 62.361907][ T37] ? init_wait_var_entry+0x200/0x200 [ 62.367204][ T37] afs_net_exit+0x1c4/0x310 [ 62.371700][ T37] ? __bpf_trace_afs_cb_miss+0x100/0x100 [ 62.377324][ T37] ops_exit_list+0xb0/0x160 [ 62.381827][ T37] cleanup_net+0x4ea/0xa00 [ 62.386239][ T37] ? __schedule+0x887/0x1eb0 [ 62.390828][ T37] ? ops_free_list.part.0+0x3d0/0x3d0 [ 62.396222][ T37] ? check_preemption_disabled+0x38/0x220 [ 62.401948][ T37] process_one_work+0x94c/0x1670 [ 62.406891][ T37] ? lock_release+0x8d0/0x8d0 [ 62.411567][ T37] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 62.416963][ T37] ? rwlock_bug.part.0+0x90/0x90 [ 62.421907][ T37] worker_thread+0x64c/0x1120 [ 62.426603][ T37] ? process_one_work+0x1670/0x1670 [ 62.431900][ T37] kthread+0x3b5/0x4a0 [ 62.435967][ T37] ? __kthread_bind_mask+0xc0/0xc0 [ 62.441069][ T37] ? __kthread_bind_mask+0xc0/0xc0 [ 62.446182][ T37] ret_from_fork+0x1f/0x30 [ 62.450650][ T37] [ 62.452989][ T37] Allocated by task 6805: [ 62.457314][ T37] save_stack+0x1b/0x40 [ 62.461467][ T37] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 62.467092][ T37] kmem_cache_alloc_trace+0x14f/0x2d0 [ 62.472464][ T37] afs_alloc_call+0x4f/0x360 [ 62.477145][ T37] afs_charge_preallocation+0xe9/0x2d0 [ 62.482596][ T37] afs_open_socket+0x294/0x360 [ 62.487349][ T37] afs_net_init+0xab4/0xe90 [ 62.491844][ T37] ops_init+0xaf/0x470 [ 62.495902][ T37] setup_net+0x2d8/0x850 [ 62.500141][ T37] copy_net_ns+0x2cf/0x5e0 [ 62.504557][ T37] create_new_namespaces+0x3f6/0xb10 [ 62.509844][ T37] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 62.515482][ T37] ksys_unshare+0x36c/0x9a0 [ 62.520102][ T37] __ia32_sys_unshare+0x2c/0x40 [ 62.524960][ T37] do_syscall_32_irqs_on+0x3f/0x60 [ 62.530076][ T37] do_fast_syscall_32+0x7f/0x120 [ 62.535011][ T37] entry_SYSENTER_compat+0x6d/0x7c [ 62.540113][ T37] [ 62.542432][ T37] Freed by task 37: [ 62.546234][ T37] save_stack+0x1b/0x40 [ 62.550385][ T37] __kasan_slab_free+0xf5/0x140 [ 62.555228][ T37] kfree+0x103/0x2c0 [ 62.559118][ T37] afs_put_call+0x345/0x440 [ 62.563614][ T37] rxrpc_discard_prealloc+0x75a/0xab0 [ 62.568980][ T37] rxrpc_listen+0x11c/0x330 [ 62.573484][ T37] afs_close_socket+0x95/0x320 [ 62.578241][ T37] afs_net_exit+0x1c4/0x310 [ 62.582738][ T37] ops_exit_list+0xb0/0x160 [ 62.587235][ T37] cleanup_net+0x4ea/0xa00 [ 62.591646][ T37] process_one_work+0x94c/0x1670 [ 62.596573][ T37] worker_thread+0x64c/0x1120 [ 62.601240][ T37] kthread+0x3b5/0x4a0 [ 62.605681][ T37] ret_from_fork+0x1f/0x30 [ 62.610081][ T37] [ 62.612402][ T37] The buggy address belongs to the object at ffff8880a251a000 [ 62.612402][ T37] which belongs to the cache kmalloc-1k of size 1024 [ 62.626453][ T37] The buggy address is located 484 bytes inside of [ 62.626453][ T37] 1024-byte region [ffff8880a251a000, ffff8880a251a400) [ 62.639806][ T37] The buggy address belongs to the page: [ 62.645611][ T37] page:ffffea0002894680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 62.655665][ T37] flags: 0xfffe0000000200(slab) [ 62.660518][ T37] raw: 00fffe0000000200 ffffea0002438a08 ffffea00029a5cc8 ffff8880aa000c40 [ 62.669100][ T37] raw: 0000000000000000 ffff8880a251a000 0000000100000002 0000000000000000 [ 62.677670][ T37] page dumped because: kasan: bad access detected [ 62.684070][ T37] [ 62.686401][ T37] Memory state around the buggy address: [ 62.692025][ T37] ffff8880a251a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.700077][ T37] ffff8880a251a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.708140][ T37] >ffff8880a251a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.716193][ T37] ^ [ 62.723380][ T37] ffff8880a251a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.731549][ T37] ffff8880a251a280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 62.740033][ T37] ================================================================== [ 62.748164][ T37] Disabling lock debugging due to kernel taint [ 62.754366][ T37] Kernel panic - not syncing: panic_on_warn set ... [ 62.760951][ T37] CPU: 1 PID: 37 Comm: kworker/u4:2 Tainted: G B 5.8.0-rc2-syzkaller #0 [ 62.770573][ T37] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.780630][ T37] Workqueue: netns cleanup_net [ 62.785378][ T37] Call Trace: [ 62.788665][ T37] dump_stack+0x18f/0x20d [ 62.792996][ T37] ? afs_wake_up_async_call+0x390/0x4a0 [ 62.798539][ T37] ? afs_put_call+0x440/0x440 [ 62.803209][ T37] panic+0x2e3/0x75c [ 62.807106][ T37] ? __warn_printk+0xf3/0xf3 [ 62.811693][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.817243][ T37] ? trace_hardirqs_on+0x55/0x220 [ 62.822270][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.827818][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.833367][ T37] ? afs_put_call+0x440/0x440 [ 62.838141][ T37] end_report+0x4d/0x53 [ 62.842291][ T37] kasan_report.cold+0xd/0x37 [ 62.849040][ T37] ? afs_wake_up_async_call+0x430/0x4a0 [ 62.854573][ T37] afs_wake_up_async_call+0x430/0x4a0 [ 62.859933][ T37] ? afs_close_socket+0x320/0x320 [ 62.864949][ T37] rxrpc_notify_socket+0x1db/0x5d0 [ 62.870052][ T37] ? afs_put_call+0x440/0x440 [ 62.874720][ T37] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 62.881139][ T37] rxrpc_call_completed+0xd0/0xf0 [ 62.886148][ T37] rxrpc_discard_prealloc+0x777/0xab0 [ 62.891509][ T37] ? lock_sock_nested+0x94/0x110 [ 62.896438][ T37] rxrpc_listen+0x11c/0x330 [ 62.900948][ T37] afs_close_socket+0x95/0x320 [ 62.905688][ T37] ? afs_purge_servers+0x181/0x330 [ 62.910972][ T37] ? afs_rx_discard_new_call+0x50/0x50 [ 62.916426][ T37] ? init_wait_var_entry+0x200/0x200 [ 62.921687][ T37] afs_net_exit+0x1c4/0x310 [ 62.926361][ T37] ? __bpf_trace_afs_cb_miss+0x100/0x100 [ 62.932087][ T37] ops_exit_list+0xb0/0x160 [ 62.936579][ T37] cleanup_net+0x4ea/0xa00 [ 62.940982][ T37] ? __schedule+0x887/0x1eb0 [ 62.945549][ T37] ? ops_free_list.part.0+0x3d0/0x3d0 [ 62.950917][ T37] ? check_preemption_disabled+0x38/0x220 [ 62.956622][ T37] process_one_work+0x94c/0x1670 [ 62.961540][ T37] ? lock_release+0x8d0/0x8d0 [ 62.966422][ T37] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 62.971834][ T37] ? rwlock_bug.part.0+0x90/0x90 [ 62.976773][ T37] worker_thread+0x64c/0x1120 [ 62.981453][ T37] ? process_one_work+0x1670/0x1670 [ 62.986659][ T37] kthread+0x3b5/0x4a0 [ 62.990802][ T37] ? __kthread_bind_mask+0xc0/0xc0 [ 62.995914][ T37] ? __kthread_bind_mask+0xc0/0xc0 [ 63.001022][ T37] ret_from_fork+0x1f/0x30 [ 63.006830][ T37] Kernel Offset: disabled [ 63.011144][ T37] Rebooting in 86400 seconds..