[....] Starting enhanced syslogd: rsyslogd[ 11.375384] audit: type=1400 audit(1515798108.472:4): avc: denied { syslog } for pid=3181 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.54' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 20.725604] ================================================================== [ 20.732989] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 20.739619] Read of size 8 at addr ffff8801c8c9e338 by task syzkaller929347/3330 [ 20.747113] [ 20.748709] CPU: 0 PID: 3330 Comm: syzkaller929347 Not tainted 4.9.76-g8e170a5 #11 [ 20.756377] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 20.765704] ffff8801c7eb78c0 ffffffff81d93149 ffffea0007232780 ffff8801c8c9e338 [ 20.773655] 0000000000000000 ffff8801c8c9e338 ffff8801c8c9e338 ffff8801c7eb78f8 [ 20.781600] ffffffff8153cb43 ffff8801c8c9e338 0000000000000008 0000000000000000 [ 20.789545] Call Trace: [ 20.792100] [] dump_stack+0xc1/0x128 [ 20.797429] [] print_address_description+0x73/0x280 [ 20.804057] [] kasan_report+0x275/0x360 [ 20.809647] [] ? __lock_acquire+0x2eff/0x3640 [ 20.815756] [] __asan_report_load8_noabort+0x14/0x20 [ 20.822473] [] __lock_acquire+0x2eff/0x3640 [ 20.828409] [] ? __lock_acquire+0x629/0x3640 [ 20.834430] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.841409] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.848387] [] ? __lock_is_held+0xa1/0xf0 [ 20.854158] [] lock_acquire+0x12e/0x410 [ 20.859753] [] ? remove_wait_queue+0x14/0x40 [ 20.865777] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 20.872060] [] ? remove_wait_queue+0x14/0x40 [ 20.878081] [] remove_wait_queue+0x14/0x40 [ 20.883930] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 20.890908] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 20.898143] [] ep_remove+0x41/0x290 [ 20.903384] [] eventpoll_release_file+0xc5/0x140 [ 20.909754] [] __fput+0x5a8/0x6e0 [ 20.914821] [] ____fput+0x15/0x20 [ 20.919889] [] task_work_run+0x115/0x190 [ 20.925563] [] do_exit+0x7e7/0x2a40 [ 20.930805] [] ? selinux_file_ioctl+0x355/0x530 [ 20.937086] [] ? release_task+0x1240/0x1240 [ 20.943021] [] ? SyS_epoll_create+0x190/0x190 [ 20.949132] [] ? entry_SYSCALL_64_fastpath+0x5/0xe2 [ 20.955760] [] do_group_exit+0x108/0x320 [ 20.961436] [] SyS_exit_group+0x1d/0x20 [ 20.967027] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 20.973565] [ 20.975158] Allocated by task 3330: [ 20.978749] save_stack_trace+0x16/0x20 [ 20.982686] save_stack+0x43/0xd0 [ 20.986102] kasan_kmalloc+0xad/0xe0 [ 20.989778] kmem_cache_alloc_trace+0xfb/0x2a0 [ 20.994323] binder_get_thread+0x15d/0x750 [ 21.000477] binder_poll+0x4a/0x210 [ 21.004074] SyS_epoll_ctl+0x11d7/0x2190 [ 21.008102] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 21.012818] [ 21.015590] Freed by task 3330: [ 21.018839] save_stack_trace+0x16/0x20 [ 21.023159] save_stack+0x43/0xd0 [ 21.026575] kasan_slab_free+0x72/0xc0 [ 21.030524] kfree+0x103/0x300 [ 21.033684] binder_thread_dec_tmpref+0x1cc/0x240 [ 21.038508] binder_thread_release+0x27d/0x540 [ 21.043056] binder_ioctl+0x9c0/0x11b0 [ 21.046904] do_vfs_ioctl+0x1aa/0x1140 [ 21.050767] SyS_ioctl+0x8f/0xc0 [ 21.054099] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 21.058815] [ 21.060409] The buggy address belongs to the object at ffff8801c8c9e280 [ 21.060409] which belongs to the cache kmalloc-512 of size 512 [ 21.073027] The buggy address is located 184 bytes inside of [ 21.073027] 512-byte region [ffff8801c8c9e280, ffff8801c8c9e480) [ 21.084863] The buggy address belongs to the page: [ 21.089757] page:ffffea0007232780 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 21.099921] flags: 0x8000000000004080(slab|head) [ 21.104645] page dumped because: kasan: bad access detected [ 21.110316] [ 21.111919] Memory state around the buggy address: [ 21.116828] ffff8801c8c9e200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.124150] ffff8801c8c9e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.131473] >ffff8801c8c9e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.138794] ^ [ 21.143946] ffff8801c8c9e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.151269] ffff8801c8c9e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.158589] ================================================================== [ 21.166027] Disabling lock debugging due to kernel taint [ 21.171440] Kernel panic - not syncing: panic_on_warn set ... [ 21.171440] [ 21.178767] CPU: 0 PID: 3330 Comm: syzkaller929347 Tainted: G B 4.9.76-g8e170a5 #11 [ 21.187650] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 21.196969] ffff8801c7eb7818 ffffffff81d93149 ffffffff84195c17 ffff8801c7eb78f0 [ 21.204916] 0000000000000000 ffff8801c8c9e338 ffff8801c8c9e338 ffff8801c7eb78e0 [ 21.212866] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 21.220831] Call Trace: [ 21.223385] [] dump_stack+0xc1/0x128 [ 21.228724] [] panic+0x1bc/0x3a8 [ 21.233706] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 21.241908] [] ? add_taint+0x40/0x50 [ 21.247243] [] kasan_end_report+0x50/0x50 [ 21.253005] [] kasan_report+0x167/0x360 [ 21.258596] [] ? __lock_acquire+0x2eff/0x3640 [ 21.264712] [] __asan_report_load8_noabort+0x14/0x20 [ 21.271430] [] __lock_acquire+0x2eff/0x3640 [ 21.277381] [] ? __lock_acquire+0x629/0x3640 [ 21.283417] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 21.290415] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 21.297390] [] ? __lock_is_held+0xa1/0xf0 [ 21.303151] [] lock_acquire+0x12e/0x410 [ 21.308738] [] ? remove_wait_queue+0x14/0x40 [ 21.314761] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 21.321041] [] ? remove_wait_queue+0x14/0x40 [ 21.327061] [] remove_wait_queue+0x14/0x40 [ 21.332909] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 21.340256] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 21.347579] [] ep_remove+0x41/0x290 [ 21.352827] [] eventpoll_release_file+0xc5/0x140 [ 21.359197] [] __fput+0x5a8/0x6e0 [ 21.364270] [] ____fput+0x15/0x20 [ 21.369338] [] task_work_run+0x115/0x190 [ 21.375023] [] do_exit+0x7e7/0x2a40 [ 21.380266] [] ? selinux_file_ioctl+0x355/0x530 [ 21.386549] [] ? release_task+0x1240/0x1240 [ 21.392484] [] ? SyS_epoll_create+0x190/0x190 [ 21.398595] [] ? entry_SYSCALL_64_fastpath+0x5/0xe2 [ 21.405223] [] do_group_exit+0x108/0x320 [ 21.410896] [] SyS_exit_group+0x1d/0x20 [ 21.416481] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 21.423632] Dumping ftrace buffer: [ 21.427138] (ftrace buffer empty) [ 21.430814] Kernel Offset: disabled [ 21.434406] Rebooting in 86400 seconds..