[ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ 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... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.244' (ECDSA) to the list of known hosts. 2020/06/19 00:15:44 fuzzer started 2020/06/19 00:15:44 connecting to host at 10.128.0.26:41369 2020/06/19 00:15:44 checking machine... 2020/06/19 00:15:44 checking revisions... 2020/06/19 00:15:44 testing simple program... syzkaller login: [ 70.382923][ T29] audit: type=1400 audit(1592525745.003:8): avc: denied { execmem } for pid=6835 comm="syz-executor.0" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 70.461283][ T6836] IPVS: ftp: loaded support on port[0] = 21 2020/06/19 00:15:45 building call list... [ 70.828455][ T21] tipc: TX() has been purged, node left! [ 71.330874][ T21] ================================================================== [ 71.339314][ T21] BUG: KASAN: use-after-free in afs_wake_up_async_call+0x6aa/0x770 [ 71.347238][ T21] Write of size 1 at addr ffff88809fc689e4 by task kworker/u4:1/21 [ 71.355159][ T21] [ 71.357578][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.8.0-rc1-syzkaller #0 [ 71.365820][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.375996][ T21] Workqueue: netns cleanup_net [ 71.380765][ T21] Call Trace: [ 71.384242][ T21] dump_stack+0x18f/0x20d [ 71.388579][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 71.394231][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 71.399779][ T21] ? afs_put_call+0xa40/0xa40 [ 71.404462][ T21] print_address_description.constprop.0.cold+0xd3/0x413 [ 71.412021][ T21] ? vprintk_func+0x97/0x1a6 [ 71.416671][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 71.423372][ T21] kasan_report.cold+0x1f/0x37 [ 71.428188][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 71.433928][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 71.439476][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 71.444862][ T21] ? afs_close_socket+0x320/0x320 [ 71.449897][ T21] ? afs_put_call+0xa40/0xa40 [ 71.454779][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 71.459897][ T21] ? afs_put_call+0xa40/0xa40 [ 71.464586][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 71.471016][ T21] rxrpc_call_completed+0xca/0xf0 [ 71.476067][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 71.481485][ T21] ? lock_sock_nested+0x94/0x110 [ 71.486437][ T21] rxrpc_listen+0x147/0x360 [ 71.490948][ T21] afs_close_socket+0x95/0x320 [ 71.495762][ T21] ? afs_purge_servers+0x16d/0x300 [ 71.500902][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 71.506401][ T21] ? init_wait_var_entry+0x200/0x200 [ 71.511717][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 71.517620][ T21] ? check_preemption_disabled+0x38/0x220 [ 71.523348][ T21] afs_net_exit+0x1bc/0x310 [ 71.527852][ T21] ? afs_net_init+0xe30/0xe30 [ 71.532534][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 71.537649][ T21] cleanup_net+0x511/0xa50 [ 71.542161][ T21] ? unregister_pernet_device+0x70/0x70 [ 71.547840][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 71.553848][ T21] process_one_work+0x965/0x1690 [ 71.558800][ T21] ? lock_release+0x800/0x800 [ 71.563579][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 71.568957][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 71.573906][ T21] worker_thread+0x96/0xe10 [ 71.578425][ T21] ? process_one_work+0x1690/0x1690 [ 71.583656][ T21] kthread+0x3b5/0x4a0 [ 71.587750][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 71.593481][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 71.599207][ T21] ret_from_fork+0x1f/0x30 [ 71.603632][ T21] [ 71.605961][ T21] Allocated by task 6836: [ 71.610294][ T21] save_stack+0x1b/0x40 [ 71.614446][ T21] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 71.620075][ T21] kmem_cache_alloc_trace+0x153/0x7d0 [ 71.625442][ T21] afs_alloc_call+0x55/0x630 [ 71.630032][ T21] afs_charge_preallocation+0xe9/0x2d0 [ 71.635591][ T21] afs_open_socket+0x292/0x360 [ 71.640369][ T21] afs_net_init+0xa6c/0xe30 [ 71.645006][ T21] ops_init+0xaf/0x420 [ 71.649079][ T21] setup_net+0x2de/0x860 [ 71.653321][ T21] copy_net_ns+0x293/0x590 [ 71.657745][ T21] create_new_namespaces+0x3fb/0xb30 [ 71.663215][ T21] unshare_nsproxy_namespaces+0xbd/0x1f0 [ 71.669572][ T21] ksys_unshare+0x43d/0x8e0 [ 71.674076][ T21] __x64_sys_unshare+0x2d/0x40 [ 71.679151][ T21] do_syscall_64+0x60/0xe0 [ 71.683660][ T21] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 71.689553][ T21] [ 71.691885][ T21] Freed by task 21: [ 71.695786][ T21] save_stack+0x1b/0x40 [ 71.700231][ T21] __kasan_slab_free+0xf7/0x140 [ 71.706124][ T21] kfree+0x109/0x2b0 [ 71.710112][ T21] afs_put_call+0x585/0xa40 [ 71.714661][ T21] rxrpc_discard_prealloc+0x764/0xab0 [ 71.720050][ T21] rxrpc_listen+0x147/0x360 [ 71.724591][ T21] afs_close_socket+0x95/0x320 [ 71.729352][ T21] afs_net_exit+0x1bc/0x310 [ 71.733946][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 71.739324][ T21] cleanup_net+0x511/0xa50 [ 71.743740][ T21] process_one_work+0x965/0x1690 [ 71.748773][ T21] worker_thread+0x96/0xe10 [ 71.753416][ T21] kthread+0x3b5/0x4a0 [ 71.757517][ T21] ret_from_fork+0x1f/0x30 [ 71.761961][ T21] [ 71.764293][ T21] The buggy address belongs to the object at ffff88809fc68800 [ 71.764293][ T21] which belongs to the cache kmalloc-1k of size 1024 [ 71.779763][ T21] The buggy address is located 484 bytes inside of [ 71.779763][ T21] 1024-byte region [ffff88809fc68800, ffff88809fc68c00) [ 71.793646][ T21] The buggy address belongs to the page: [ 71.799293][ T21] page:ffffea00027f1a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 71.808777][ T21] flags: 0xfffe0000000200(slab) [ 71.813842][ T21] raw: 00fffe0000000200 ffffea00027d8c48 ffffea00029f01c8 ffff8880aa000c40 [ 71.822879][ T21] raw: 0000000000000000 ffff88809fc68000 0000000100000002 0000000000000000 [ 71.831502][ T21] page dumped because: kasan: bad access detected [ 71.837909][ T21] [ 71.840244][ T21] Memory state around the buggy address: [ 71.846067][ T21] ffff88809fc68880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.854212][ T21] ffff88809fc68900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.862384][ T21] >ffff88809fc68980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.870702][ T21] ^ [ 71.878259][ T21] ffff88809fc68a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.886790][ T21] ffff88809fc68a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 71.895026][ T21] ================================================================== [ 71.903096][ T21] Disabling lock debugging due to kernel taint [ 71.909280][ T21] Kernel panic - not syncing: panic_on_warn set ... [ 71.916050][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Tainted: G B 5.8.0-rc1-syzkaller #0 [ 71.925661][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 71.935713][ T21] Workqueue: netns cleanup_net [ 71.940473][ T21] Call Trace: [ 71.944028][ T21] dump_stack+0x18f/0x20d [ 71.948357][ T21] ? afs_wake_up_async_call+0x670/0x770 [ 71.953905][ T21] ? afs_put_call+0xa40/0xa40 [ 71.958575][ T21] panic+0x2e3/0x75c [ 71.962472][ T21] ? __warn_printk+0xf3/0xf3 [ 71.967064][ T21] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 71.973221][ T21] ? trace_hardirqs_on+0x55/0x220 [ 71.978251][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 71.983797][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 71.989345][ T21] ? afs_put_call+0xa40/0xa40 [ 71.994055][ T21] end_report+0x4d/0x53 [ 71.998235][ T21] kasan_report.cold+0xd/0x37 [ 72.002918][ T21] ? rcu_read_lock_held_common+0x51/0xa0 [ 72.008654][ T21] ? afs_wake_up_async_call+0x6aa/0x770 [ 72.014207][ T21] afs_wake_up_async_call+0x6aa/0x770 [ 72.019584][ T21] ? afs_close_socket+0x320/0x320 [ 72.024604][ T21] ? afs_put_call+0xa40/0xa40 [ 72.029450][ T21] rxrpc_notify_socket+0x1db/0x5d0 [ 72.034733][ T21] ? afs_put_call+0xa40/0xa40 [ 72.039592][ T21] __rxrpc_set_call_completion.part.0+0x172/0x410 [ 72.046003][ T21] rxrpc_call_completed+0xca/0xf0 [ 72.051072][ T21] rxrpc_discard_prealloc+0x781/0xab0 [ 72.056445][ T21] ? lock_sock_nested+0x94/0x110 [ 72.061385][ T21] rxrpc_listen+0x147/0x360 [ 72.065907][ T21] afs_close_socket+0x95/0x320 [ 72.070761][ T21] ? afs_purge_servers+0x16d/0x300 [ 72.075897][ T21] ? afs_rx_discard_new_call+0x50/0x50 [ 72.081534][ T21] ? init_wait_var_entry+0x200/0x200 [ 72.086843][ T21] ? rcu_read_lock_held_common+0xa0/0xa0 [ 72.092474][ T21] ? check_preemption_disabled+0x38/0x220 [ 72.098190][ T21] afs_net_exit+0x1bc/0x310 [ 72.102686][ T21] ? afs_net_init+0xe30/0xe30 [ 72.107361][ T21] ops_exit_list.isra.0+0xa8/0x150 [ 72.112496][ T21] cleanup_net+0x511/0xa50 [ 72.116914][ T21] ? unregister_pernet_device+0x70/0x70 [ 72.122557][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 72.128537][ T21] process_one_work+0x965/0x1690 [ 72.133476][ T21] ? lock_release+0x800/0x800 [ 72.138211][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 72.143607][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 72.148546][ T21] worker_thread+0x96/0xe10 [ 72.153049][ T21] ? process_one_work+0x1690/0x1690 [ 72.158239][ T21] kthread+0x3b5/0x4a0 [ 72.162303][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 72.168059][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 72.173773][ T21] ret_from_fork+0x1f/0x30 [ 72.179673][ T21] Kernel Offset: disabled [ 72.184203][ T21] Rebooting in 86400 seconds..