[....] Starting enhanced syslogd: rsyslogd[ 15.833119] audit: type=1400 audit(1517603512.352:4): avc: denied { syslog } for pid=3906 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 '10.128.0.2' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 25.972454] ================================================================== [ 25.979830] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 25.986471] Read of size 8 at addr ffff8801bd836338 by task syzkaller263535/4055 [ 25.993969] [ 25.995573] CPU: 0 PID: 4055 Comm: syzkaller263535 Not tainted 4.9.79-g71f1469 #34 [ 26.003244] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.012575] ffff8801d37ef870 ffffffff81d94829 ffffea0006f60d80 ffff8801bd836338 [ 26.020554] 0000000000000000 ffff8801bd836338 ffff8801bd836338 ffff8801d37ef8a8 [ 26.028512] ffffffff8153e083 ffff8801bd836338 0000000000000008 0000000000000000 [ 26.036476] Call Trace: [ 26.039034] [] dump_stack+0xc1/0x128 [ 26.044366] [] print_address_description+0x73/0x280 [ 26.050999] [] kasan_report+0x275/0x360 [ 26.056608] [] ? __lock_acquire+0x2eff/0x3640 [ 26.062717] [] __asan_report_load8_noabort+0x14/0x20 [ 26.069437] [] __lock_acquire+0x2eff/0x3640 [ 26.075373] [] ? __lock_acquire+0x629/0x3640 [ 26.081396] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.088377] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.095355] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.102337] [] ? mark_held_locks+0xaf/0x100 [ 26.108279] [] ? mutex_lock_nested+0x5e3/0x870 [ 26.114477] [] lock_acquire+0x12e/0x410 [ 26.120070] [] ? remove_wait_queue+0x14/0x40 [ 26.126097] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 26.132381] [] ? remove_wait_queue+0x14/0x40 [ 26.138408] [] remove_wait_queue+0x14/0x40 [ 26.144262] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 26.151247] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 26.158488] [] ? ep_free+0x1b0/0x1b0 [ 26.163818] [] ep_free+0x96/0x1b0 [ 26.168898] [] ? ep_free+0x1b0/0x1b0 [ 26.174242] [] ep_eventpoll_release+0x44/0x60 [ 26.180356] [] __fput+0x28c/0x6e0 [ 26.185428] [] ____fput+0x15/0x20 [ 26.190510] [] task_work_run+0x115/0x190 [ 26.196199] [] do_exit+0x7e7/0x2a40 [ 26.201445] [] ? __pmd_alloc+0x410/0x410 [ 26.207130] [] ? release_task+0x1240/0x1240 [ 26.213072] [] ? __do_page_fault+0x5ec/0xd40 [ 26.219099] [] ? up_read+0x1a/0x40 [ 26.224257] [] ? __do_page_fault+0x3bd/0xd40 [ 26.230284] [] do_group_exit+0x108/0x320 [ 26.235971] [] ? do_group_exit+0x320/0x320 [ 26.241825] [] SyS_exit_group+0x1d/0x20 [ 26.247418] [] do_fast_syscall_32+0x2f7/0x890 [ 26.253540] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.260176] [] entry_SYSENTER_compat+0x74/0x83 [ 26.266370] [ 26.267965] Allocated by task 4055: [ 26.271563] save_stack_trace+0x16/0x20 [ 26.275509] save_stack+0x43/0xd0 [ 26.278927] kasan_kmalloc+0xad/0xe0 [ 26.282607] kmem_cache_alloc_trace+0xfb/0x2a0 [ 26.287158] binder_get_thread+0x15d/0x750 [ 26.291361] binder_poll+0x4a/0x210 [ 26.294956] SyS_epoll_ctl+0x11d7/0x2190 [ 26.298994] do_fast_syscall_32+0x2f7/0x890 [ 26.303287] entry_SYSENTER_compat+0x74/0x83 [ 26.307659] [ 26.309255] Freed by task 4055: [ 26.312503] save_stack_trace+0x16/0x20 [ 26.316444] save_stack+0x43/0xd0 [ 26.319868] kasan_slab_free+0x72/0xc0 [ 26.323723] kfree+0x103/0x300 [ 26.326888] binder_thread_dec_tmpref+0x1cc/0x240 [ 26.331699] binder_thread_release+0x27d/0x540 [ 26.336251] binder_ioctl+0x9c0/0x11b0 [ 26.340106] compat_SyS_ioctl+0x15f/0x2050 [ 26.344312] do_fast_syscall_32+0x2f7/0x890 [ 26.348602] entry_SYSENTER_compat+0x74/0x83 [ 26.352989] [ 26.354595] The buggy address belongs to the object at ffff8801bd836280 [ 26.354595] which belongs to the cache kmalloc-512 of size 512 [ 26.367223] The buggy address is located 184 bytes inside of [ 26.367223] 512-byte region [ffff8801bd836280, ffff8801bd836480) [ 26.379064] The buggy address belongs to the page: [ 26.383972] page:ffffea0006f60d80 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 26.394145] flags: 0x8000000000004080(slab|head) [ 26.398871] page dumped because: kasan: bad access detected [ 26.404547] [ 26.406139] Memory state around the buggy address: [ 26.411036] ffff8801bd836200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 26.418361] ffff8801bd836280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.425685] >ffff8801bd836300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.433009] ^ [ 26.438166] ffff8801bd836380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.445492] ffff8801bd836400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.452815] ================================================================== [ 26.460141] Disabling lock debugging due to kernel taint [ 26.465564] Kernel panic - not syncing: panic_on_warn set ... [ 26.465564] [ 26.472911] CPU: 0 PID: 4055 Comm: syzkaller263535 Tainted: G B 4.9.79-g71f1469 #34 [ 26.481800] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.491136] ffff8801d37ef7c8 ffffffff81d94829 ffffffff8419709f ffff8801d37ef8a0 [ 26.499094] 0000000000000000 ffff8801bd836338 ffff8801bd836338 ffff8801d37ef890 [ 26.507053] ffffffff8142f531 0000000041b58ab3 ffffffff8418ab10 ffffffff8142f375 [ 26.515023] Call Trace: [ 26.517582] [] dump_stack+0xc1/0x128 [ 26.522914] [] panic+0x1bc/0x3a8 [ 26.527906] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 26.536105] [] ? add_taint+0x40/0x50 [ 26.541439] [] kasan_end_report+0x50/0x50 [ 26.547205] [] kasan_report+0x167/0x360 [ 26.552798] [] ? __lock_acquire+0x2eff/0x3640 [ 26.558912] [] __asan_report_load8_noabort+0x14/0x20 [ 26.565635] [] __lock_acquire+0x2eff/0x3640 [ 26.571577] [] ? __lock_acquire+0x629/0x3640 [ 26.577604] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.584586] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.591565] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 26.598547] [] ? mark_held_locks+0xaf/0x100 [ 26.604503] [] ? mutex_lock_nested+0x5e3/0x870 [ 26.604509] [] lock_acquire+0x12e/0x410 [ 26.604519] [] ? remove_wait_queue+0x14/0x40 [ 26.604524] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 26.604529] [] ? remove_wait_queue+0x14/0x40 [ 26.604535] [] remove_wait_queue+0x14/0x40 [ 26.604544] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 26.604550] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 26.604556] [] ? ep_free+0x1b0/0x1b0 [ 26.604562] [] ep_free+0x96/0x1b0 [ 26.604567] [] ? ep_free+0x1b0/0x1b0 [ 26.604574] [] ep_eventpoll_release+0x44/0x60 [ 26.604579] [] __fput+0x28c/0x6e0 [ 26.604585] [] ____fput+0x15/0x20 [ 26.604591] [] task_work_run+0x115/0x190 [ 26.604599] [] do_exit+0x7e7/0x2a40 [ 26.604606] [] ? __pmd_alloc+0x410/0x410 [ 26.604612] [] ? release_task+0x1240/0x1240 [ 26.604620] [] ? __do_page_fault+0x5ec/0xd40 [ 26.604627] [] ? up_read+0x1a/0x40 [ 26.604633] [] ? __do_page_fault+0x3bd/0xd40 [ 26.604639] [] do_group_exit+0x108/0x320 [ 26.604646] [] ? do_group_exit+0x320/0x320 [ 26.604653] [] SyS_exit_group+0x1d/0x20 [ 26.604659] [] do_fast_syscall_32+0x2f7/0x890 [ 26.604665] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.604672] [] entry_SYSENTER_compat+0x74/0x83 [ 26.611126] Dumping ftrace buffer: [ 26.611129] (ftrace buffer empty) [ 26.611131] Kernel Offset: disabled [ 26.773562] Rebooting in 86400 seconds..