[....] Starting enhanced syslogd: rsyslogd[ 12.679441] audit: type=1400 audit(1514775454.630:4): avc: denied { syslog } for pid=3166 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] 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 '10.128.15.217' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 19.516973] ================================================================== [ 19.524333] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 19.530961] Read of size 8 at addr ffff8801cb132838 by task syzkaller313044/3318 [ 19.538455] [ 19.540051] CPU: 0 PID: 3318 Comm: syzkaller313044 Not tainted 4.9.73-gf3f3457 #1 [ 19.547637] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.556957] ffff8801ca3178e0 ffffffff81d922b9 ffffea00072c4c80 ffff8801cb132838 [ 19.564903] 0000000000000000 ffff8801cb132838 ffff8801cb132838 ffff8801ca317918 [ 19.572847] ffffffff8153bab3 ffff8801cb132838 0000000000000008 0000000000000000 [ 19.580787] Call Trace: [ 19.583339] [] dump_stack+0xc1/0x128 [ 19.588668] [] print_address_description+0x73/0x280 [ 19.595297] [] kasan_report+0x275/0x360 [ 19.600887] [] ? __lock_acquire+0x2eff/0x3640 [ 19.606994] [] __asan_report_load8_noabort+0x14/0x20 [ 19.613710] [] __lock_acquire+0x2eff/0x3640 [ 19.619644] [] ? __lock_acquire+0x629/0x3640 [ 19.625665] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.632640] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.639616] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.646593] [] ? mark_held_locks+0xaf/0x100 [ 19.652528] [] ? mutex_lock_nested+0x5e3/0x870 [ 19.658723] [] lock_acquire+0x12e/0x410 [ 19.664309] [] ? remove_wait_queue+0x14/0x40 [ 19.670334] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 19.676615] [] ? remove_wait_queue+0x14/0x40 [ 19.682635] [] remove_wait_queue+0x14/0x40 [ 19.688483] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 19.695464] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 19.702703] [] ? ep_free+0x1b0/0x1b0 [ 19.708029] [] ep_free+0x96/0x1b0 [ 19.713094] [] ? ep_free+0x1b0/0x1b0 [ 19.718420] [] ep_eventpoll_release+0x44/0x60 [ 19.724531] [] __fput+0x28c/0x6e0 [ 19.729603] [] ____fput+0x15/0x20 [ 19.734669] [] task_work_run+0x115/0x190 [ 19.740345] [] do_exit+0x7e7/0x2a40 [ 19.745587] [] ? selinux_file_ioctl+0x355/0x530 [ 19.751868] [] ? release_task+0x1240/0x1240 [ 19.757803] [] ? SyS_epoll_create+0x190/0x190 [ 19.763914] [] ? entry_SYSCALL_64_fastpath+0x5/0xc6 [ 19.770544] [] do_group_exit+0x108/0x320 [ 19.776220] [] SyS_exit_group+0x1d/0x20 [ 19.781808] [] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.788346] [ 19.789938] Allocated by task 3318: [ 19.793529] save_stack_trace+0x16/0x20 [ 19.797467] save_stack+0x43/0xd0 [ 19.800881] kasan_kmalloc+0xad/0xe0 [ 19.804557] kmem_cache_alloc_trace+0xfb/0x2a0 [ 19.809103] binder_get_thread+0x15d/0x750 [ 19.813300] binder_poll+0x4a/0x210 [ 19.816891] SyS_epoll_ctl+0x11d7/0x2190 [ 19.820914] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.825629] [ 19.827219] Freed by task 3318: [ 19.830460] save_stack_trace+0x16/0x20 [ 19.834396] save_stack+0x43/0xd0 [ 19.837813] kasan_slab_free+0x72/0xc0 [ 19.841661] kfree+0x103/0x300 [ 19.844817] binder_thread_dec_tmpref+0x1cc/0x240 [ 19.849629] binder_thread_release+0x27d/0x540 [ 19.854170] binder_ioctl+0x9c0/0x11b0 [ 19.858021] do_vfs_ioctl+0x1aa/0x1140 [ 19.861869] SyS_ioctl+0x8f/0xc0 [ 19.865198] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.869913] [ 19.871503] The buggy address belongs to the object at ffff8801cb132780 [ 19.871503] which belongs to the cache kmalloc-512 of size 512 [ 19.884121] The buggy address is located 184 bytes inside of [ 19.884121] 512-byte region [ffff8801cb132780, ffff8801cb132980) [ 19.895958] The buggy address belongs to the page: [ 19.900850] page:ffffea00072c4c80 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 19.910999] flags: 0x8000000000004080(slab|head) [ 19.915714] page dumped because: kasan: bad access detected [ 19.921384] [ 19.922973] Memory state around the buggy address: [ 19.927864] ffff8801cb132700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 19.935185] ffff8801cb132780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.942507] >ffff8801cb132800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.949827] ^ [ 19.954979] ffff8801cb132880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.962300] ffff8801cb132900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.969619] ================================================================== [ 19.976937] Disabling lock debugging due to kernel taint [ 19.982347] Kernel panic - not syncing: panic_on_warn set ... [ 19.982347] [ 19.989674] CPU: 0 PID: 3318 Comm: syzkaller313044 Tainted: G B 4.9.73-gf3f3457 #1 [ 19.998470] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 20.007788] ffff8801ca317838 ffffffff81d922b9 ffffffff841955bf ffff8801ca317910 [ 20.015812] 0000000000000000 ffff8801cb132838 ffff8801cb132838 ffff8801ca317900 [ 20.023750] ffffffff8142d741 0000000041b58ab3 ffffffff84189000 ffffffff8142d585 [ 20.031686] Call Trace: [ 20.034240] [] dump_stack+0xc1/0x128 [ 20.039567] [] panic+0x1bc/0x3a8 [ 20.044547] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 20.052750] [] ? add_taint+0x40/0x50 [ 20.058079] [] kasan_end_report+0x50/0x50 [ 20.063844] [] kasan_report+0x167/0x360 [ 20.069434] [] ? __lock_acquire+0x2eff/0x3640 [ 20.075541] [] __asan_report_load8_noabort+0x14/0x20 [ 20.082257] [] __lock_acquire+0x2eff/0x3640 [ 20.088190] [] ? __lock_acquire+0x629/0x3640 [ 20.094210] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.101620] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.108598] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.115580] [] ? mark_held_locks+0xaf/0x100 [ 20.121516] [] ? mutex_lock_nested+0x5e3/0x870 [ 20.127711] [] lock_acquire+0x12e/0x410 [ 20.133298] [] ? remove_wait_queue+0x14/0x40 [ 20.139319] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 20.145602] [] ? remove_wait_queue+0x14/0x40 [ 20.151623] [] remove_wait_queue+0x14/0x40 [ 20.157470] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 20.164444] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 20.171680] [] ? ep_free+0x1b0/0x1b0 [ 20.177006] [] ep_free+0x96/0x1b0 [ 20.182069] [] ? ep_free+0x1b0/0x1b0 [ 20.187394] [] ep_eventpoll_release+0x44/0x60 [ 20.193501] [] __fput+0x28c/0x6e0 [ 20.198566] [] ____fput+0x15/0x20 [ 20.203630] [] task_work_run+0x115/0x190 [ 20.209305] [] do_exit+0x7e7/0x2a40 [ 20.214555] [] ? selinux_file_ioctl+0x355/0x530 [ 20.220834] [] ? release_task+0x1240/0x1240 [ 20.226769] [] ? SyS_epoll_create+0x190/0x190 [ 20.232880] [] ? entry_SYSCALL_64_fastpath+0x5/0xc6 [ 20.239509] [] do_group_exit+0x108/0x320 [ 20.245183] [] SyS_exit_group+0x1d/0x20 [ 20.250769] [] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 20.257782] Dumping ftrace buffer: [ 20.261293] (ftrace buffer empty) [ 20.264967] Kernel Offset: disabled [ 20.268555] Rebooting in 86400 seconds..