[....] Starting enhanced syslogd: rsyslogd[ 12.560891] audit: type=1400 audit(1515879541.527:4): avc: denied { syslog } for pid=3178 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 '10.128.0.50' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 27.735111] ================================================================== [ 27.742506] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 27.749146] Read of size 8 at addr ffff8801c8297c38 by task syzkaller246716/3335 [ 27.756655] [ 27.758266] CPU: 0 PID: 3335 Comm: syzkaller246716 Not tainted 4.9.76-g8e170a5 #11 [ 27.765997] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.775336] ffff8801c83978e0 ffffffff81d93149 ffffea000720a580 ffff8801c8297c38 [ 27.783339] 0000000000000000 ffff8801c8297c38 ffff8801c8297c38 ffff8801c8397918 [ 27.791293] ffffffff8153cb43 ffff8801c8297c38 0000000000000008 0000000000000000 [ 27.799264] Call Trace: [ 27.801833] [] dump_stack+0xc1/0x128 [ 27.807174] [] print_address_description+0x73/0x280 [ 27.813848] [] kasan_report+0x275/0x360 [ 27.819453] [] ? __lock_acquire+0x2eff/0x3640 [ 27.825580] [] __asan_report_load8_noabort+0x14/0x20 [ 27.832305] [] __lock_acquire+0x2eff/0x3640 [ 27.838330] [] ? __lock_acquire+0x629/0x3640 [ 27.844368] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.851355] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.858343] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.865324] [] ? mark_held_locks+0xaf/0x100 [ 27.871263] [] ? mutex_lock_nested+0x5e3/0x870 [ 27.877461] [] lock_acquire+0x12e/0x410 [ 27.883061] [] ? remove_wait_queue+0x14/0x40 [ 27.889085] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.895381] [] ? remove_wait_queue+0x14/0x40 [ 27.901414] [] remove_wait_queue+0x14/0x40 [ 27.907265] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 27.914248] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 27.921501] [] ? ep_free+0x1b0/0x1b0 [ 27.926842] [] ep_free+0x96/0x1b0 [ 27.931911] [] ? ep_free+0x1b0/0x1b0 [ 27.937242] [] ep_eventpoll_release+0x44/0x60 [ 27.943365] [] __fput+0x28c/0x6e0 [ 27.948435] [] ____fput+0x15/0x20 [ 27.953514] [] task_work_run+0x115/0x190 [ 27.959201] [] do_exit+0x7e7/0x2a40 [ 27.964456] [] ? selinux_file_ioctl+0x355/0x530 [ 27.970742] [] ? release_task+0x1240/0x1240 [ 27.976688] [] ? SyS_epoll_create+0x190/0x190 [ 27.982814] [] ? entry_SYSCALL_64_fastpath+0x5/0xe2 [ 27.989447] [] do_group_exit+0x108/0x320 [ 27.995136] [] SyS_exit_group+0x1d/0x20 [ 28.000730] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 28.007283] [ 28.008876] Allocated by task 3335: [ 28.012732] save_stack_trace+0x16/0x20 [ 28.016678] save_stack+0x43/0xd0 [ 28.020112] kasan_kmalloc+0xad/0xe0 [ 28.023806] kmem_cache_alloc_trace+0xfb/0x2a0 [ 28.028366] binder_get_thread+0x15d/0x750 [ 28.032565] binder_poll+0x4a/0x210 [ 28.036158] SyS_epoll_ctl+0x11d7/0x2190 [ 28.040195] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 28.044913] [ 28.046505] Freed by task 3335: [ 28.049751] save_stack_trace+0x16/0x20 [ 28.053692] save_stack+0x43/0xd0 [ 28.057111] kasan_slab_free+0x72/0xc0 [ 28.060964] kfree+0x103/0x300 [ 28.064124] binder_thread_dec_tmpref+0x1cc/0x240 [ 28.068931] binder_thread_release+0x27d/0x540 [ 28.073479] binder_ioctl+0x9c0/0x11b0 [ 28.077342] do_vfs_ioctl+0x1aa/0x1140 [ 28.081196] SyS_ioctl+0x8f/0xc0 [ 28.084528] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 28.089249] [ 28.090845] The buggy address belongs to the object at ffff8801c8297b80 [ 28.090845] which belongs to the cache kmalloc-512 of size 512 [ 28.103480] The buggy address is located 184 bytes inside of [ 28.103480] 512-byte region [ffff8801c8297b80, ffff8801c8297d80) [ 28.115325] The buggy address belongs to the page: [ 28.120224] page:ffffea000720a580 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 28.130385] flags: 0x8000000000004080(slab|head) [ 28.135104] page dumped because: kasan: bad access detected [ 28.140797] [ 28.142393] Memory state around the buggy address: [ 28.147287] ffff8801c8297b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 28.154614] ffff8801c8297b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.161943] >ffff8801c8297c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.169269] ^ [ 28.174451] ffff8801c8297c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.181777] ffff8801c8297d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.189107] ================================================================== [ 28.196519] Disabling lock debugging due to kernel taint [ 28.201945] Kernel panic - not syncing: panic_on_warn set ... [ 28.201945] [ 28.209277] CPU: 0 PID: 3335 Comm: syzkaller246716 Tainted: G B 4.9.76-g8e170a5 #11 [ 28.218164] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.227492] ffff8801c8397838 ffffffff81d93149 ffffffff84195c17 ffff8801c8397910 [ 28.235460] 0000000000000000 ffff8801c8297c38 ffff8801c8297c38 ffff8801c8397900 [ 28.243412] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 28.251379] Call Trace: [ 28.253946] [] dump_stack+0xc1/0x128 [ 28.259277] [] panic+0x1bc/0x3a8 [ 28.264262] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 28.272470] [] ? add_taint+0x40/0x50 [ 28.277802] [] kasan_end_report+0x50/0x50 [ 28.283574] [] kasan_report+0x167/0x360 [ 28.289165] [] ? __lock_acquire+0x2eff/0x3640 [ 28.295277] [] __asan_report_load8_noabort+0x14/0x20 [ 28.301998] [] __lock_acquire+0x2eff/0x3640 [ 28.307945] [] ? __lock_acquire+0x629/0x3640 [ 28.313968] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.320956] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.327937] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.334930] [] ? mark_held_locks+0xaf/0x100 [ 28.340872] [] ? mutex_lock_nested+0x5e3/0x870 [ 28.347079] [] lock_acquire+0x12e/0x410 [ 28.352684] [] ? remove_wait_queue+0x14/0x40 [ 28.358719] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.365002] [] ? remove_wait_queue+0x14/0x40 [ 28.371027] [] remove_wait_queue+0x14/0x40 [ 28.376879] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 28.383872] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 28.391113] [] ? ep_free+0x1b0/0x1b0 [ 28.396451] [] ep_free+0x96/0x1b0 [ 28.401696] [] ? ep_free+0x1b0/0x1b0 [ 28.407027] [] ep_eventpoll_release+0x44/0x60 [ 28.413141] [] __fput+0x28c/0x6e0 [ 28.418222] [] ____fput+0x15/0x20 [ 28.423294] [] task_work_run+0x115/0x190 [ 28.428985] [] do_exit+0x7e7/0x2a40 [ 28.434242] [] ? selinux_file_ioctl+0x355/0x530 [ 28.440527] [] ? release_task+0x1240/0x1240 [ 28.446468] [] ? SyS_epoll_create+0x190/0x190 [ 28.452582] [] ? entry_SYSCALL_64_fastpath+0x5/0xe2 [ 28.459228] [] do_group_exit+0x108/0x320 [ 28.464905] [] SyS_exit_group+0x1d/0x20 [ 28.470496] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 28.477077] Dumping ftrace buffer: [ 28.480602] (ftrace buffer empty) [ 28.484280] Kernel Offset: disabled [ 28.487874] Rebooting in 86400 seconds..