[....] Starting enhanced syslogd: rsyslogd[ 10.851653] audit: type=1400 audit(1515467861.038:4): avc: denied { syslog } for pid=3173 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 '10.128.0.57' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 21.763122] ================================================================== [ 21.764232] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 21.765120] Read of size 8 at addr ffff8801c9106fb8 by task syzkaller445859/3328 [ 21.766102] [ 21.766333] CPU: 1 PID: 3328 Comm: syzkaller445859 Not tainted 4.9.75-gb54d99a #18 [ 21.767350] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 21.768570] ffff8801cbd37870 ffffffff81d93049 ffffea0007244180 ffff8801c9106fb8 [ 21.769708] 0000000000000000 ffff8801c9106fb8 ffff8801c9106fb8 ffff8801cbd378a8 [ 21.770896] ffffffff8153ca53 ffff8801c9106fb8 0000000000000008 0000000000000000 [ 21.772093] Call Trace: [ 21.772451] [] dump_stack+0xc1/0x128 [ 21.773183] [] print_address_description+0x73/0x280 [ 21.774058] [] kasan_report+0x275/0x360 [ 21.774813] [] ? __lock_acquire+0x2eff/0x3640 [ 21.775623] [] __asan_report_load8_noabort+0x14/0x20 [ 21.776512] [] __lock_acquire+0x2eff/0x3640 [ 21.777310] [] ? __lock_acquire+0x629/0x3640 [ 21.778128] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 21.779063] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 21.780027] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 21.780965] [] ? mark_held_locks+0xaf/0x100 [ 21.781777] [] ? mutex_lock_nested+0x5e3/0x870 [ 21.782617] [] lock_acquire+0x12e/0x410 [ 21.784065] [] ? remove_wait_queue+0x14/0x40 [ 21.790094] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 21.796380] [] ? remove_wait_queue+0x14/0x40 [ 21.802406] [] remove_wait_queue+0x14/0x40 [ 21.808261] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 21.815249] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 21.822494] [] ? ep_free+0x1b0/0x1b0 [ 21.827824] [] ep_free+0x96/0x1b0 [ 21.832893] [] ? ep_free+0x1b0/0x1b0 [ 21.838224] [] ep_eventpoll_release+0x44/0x60 [ 21.845652] [] __fput+0x28c/0x6e0 [ 21.851852] [] ____fput+0x15/0x20 [ 21.856934] [] task_work_run+0x115/0x190 [ 21.862614] [] do_exit+0x7e7/0x2a40 [ 21.867864] [] ? __pmd_alloc+0x410/0x410 [ 21.873544] [] ? release_task+0x1240/0x1240 [ 21.879487] [] ? __do_page_fault+0x5ec/0xd40 [ 21.885515] [] ? up_read+0x1a/0x40 [ 21.890674] [] ? __do_page_fault+0x3bd/0xd40 [ 21.896700] [] do_group_exit+0x108/0x320 [ 21.904108] [] ? do_group_exit+0x320/0x320 [ 21.909968] [] SyS_exit_group+0x1d/0x20 [ 21.915559] [] do_fast_syscall_32+0x2f7/0x890 [ 21.921673] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 21.928306] [] entry_SYSENTER_compat+0x74/0x83 [ 21.934503] [ 21.936100] Allocated by task 3328: [ 21.939698] save_stack_trace+0x16/0x20 [ 21.943648] save_stack+0x43/0xd0 [ 21.947067] kasan_kmalloc+0xad/0xe0 [ 21.950746] kmem_cache_alloc_trace+0xfb/0x2a0 [ 21.955297] binder_get_thread+0x15d/0x750 [ 21.959497] binder_poll+0x4a/0x210 [ 21.963104] SyS_epoll_ctl+0x11d7/0x2190 [ 21.967129] do_fast_syscall_32+0x2f7/0x890 [ 21.971417] entry_SYSENTER_compat+0x74/0x83 [ 21.975788] [ 21.977394] Freed by task 3328: [ 21.980640] save_stack_trace+0x16/0x20 [ 21.984579] save_stack+0x43/0xd0 [ 21.987997] kasan_slab_free+0x72/0xc0 [ 21.991850] kfree+0x103/0x300 [ 21.995010] binder_thread_dec_tmpref+0x1cc/0x240 [ 21.999829] binder_thread_release+0x27d/0x540 [ 22.004387] binder_ioctl+0x9c0/0x11b0 [ 22.008244] compat_SyS_ioctl+0x15f/0x2050 [ 22.012460] do_fast_syscall_32+0x2f7/0x890 [ 22.016754] entry_SYSENTER_compat+0x74/0x83 [ 22.021139] [ 22.022737] The buggy address belongs to the object at ffff8801c9106f00 [ 22.022737] which belongs to the cache kmalloc-512 of size 512 [ 22.035362] The buggy address is located 184 bytes inside of [ 22.035362] 512-byte region [ffff8801c9106f00, ffff8801c9107100) [ 22.047211] The buggy address belongs to the page: [ 22.052118] page:ffffea0007244180 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 22.062279] flags: 0x8000000000004080(slab|head) [ 22.066997] page dumped because: kasan: bad access detected [ 22.072672] [ 22.074265] Memory state around the buggy address: [ 22.079164] ffff8801c9106e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 22.086576] ffff8801c9106f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 22.093902] >ffff8801c9106f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 22.101235] ^ [ 22.106404] ffff8801c9107000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 22.113736] ffff8801c9107080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 22.121061] ================================================================== [ 22.128383] Disabling lock debugging due to kernel taint [ 22.133797] Kernel panic - not syncing: panic_on_warn set ... [ 22.133797] [ 22.141127] CPU: 1 PID: 3328 Comm: syzkaller445859 Tainted: G B 4.9.75-gb54d99a #18 [ 22.150015] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 22.159338] ffff8801cbd377c8 ffffffff81d93049 ffffffff84195be7 ffff8801cbd378a0 [ 22.167301] 0000000000000000 ffff8801c9106fb8 ffff8801c9106fb8 ffff8801cbd37890 [ 22.175262] ffffffff8142e281 0000000041b58ab3 ffffffff84189648 ffffffff8142e0c5 [ 22.183216] Call Trace: [ 22.185772] [] dump_stack+0xc1/0x128 [ 22.191107] [] panic+0x1bc/0x3a8 [ 22.196089] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 22.205079] [] ? add_taint+0x40/0x50 [ 22.210422] [] kasan_end_report+0x50/0x50 [ 22.216622] [] kasan_report+0x167/0x360 [ 22.222217] [] ? __lock_acquire+0x2eff/0x3640 [ 22.228330] [] __asan_report_load8_noabort+0x14/0x20 [ 22.235055] [] __lock_acquire+0x2eff/0x3640 [ 22.240999] [] ? __lock_acquire+0x629/0x3640 [ 22.247023] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 22.254013] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 22.261002] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 22.267984] [] ? mark_held_locks+0xaf/0x100 [ 22.273926] [] ? mutex_lock_nested+0x5e3/0x870 [ 22.280133] [] lock_acquire+0x12e/0x410 [ 22.285724] [] ? remove_wait_queue+0x14/0x40 [ 22.291752] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 22.298038] [] ? remove_wait_queue+0x14/0x40 [ 22.304151] [] remove_wait_queue+0x14/0x40 [ 22.310006] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 22.316986] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 22.324237] [] ? ep_free+0x1b0/0x1b0 [ 22.329571] [] ep_free+0x96/0x1b0 [ 22.334641] [] ? ep_free+0x1b0/0x1b0 [ 22.339983] [] ep_eventpoll_release+0x44/0x60 [ 22.346097] [] __fput+0x28c/0x6e0 [ 22.351178] [] ____fput+0x15/0x20 [ 22.356249] [] task_work_run+0x115/0x190 [ 22.361928] [] do_exit+0x7e7/0x2a40 [ 22.367170] [] ? __pmd_alloc+0x410/0x410 [ 22.372848] [] ? release_task+0x1240/0x1240 [ 22.378802] [] ? __do_page_fault+0x5ec/0xd40 [ 22.384828] [] ? up_read+0x1a/0x40 [ 22.389986] [] ? __do_page_fault+0x3bd/0xd40 [ 22.396012] [] do_group_exit+0x108/0x320 [ 22.401692] [] ? do_group_exit+0x320/0x320 [ 22.407543] [] SyS_exit_group+0x1d/0x20 [ 22.413145] [] do_fast_syscall_32+0x2f7/0x890 [ 22.419267] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 22.425901] [] entry_SYSENTER_compat+0x74/0x83 [ 22.432502] Dumping ftrace buffer: [ 22.436012] (ftrace buffer empty) [ 22.439700] Kernel Offset: disabled [ 22.443293] Rebooting in 86400 seconds..