[....] Starting enhanced syslogd: rsyslogd[ 13.290091] audit: type=1400 audit(1515972461.162:4): avc: denied { syslog } for pid=3169 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 '10.128.0.39' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 28.379322] ================================================================== [ 28.386729] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 28.393371] Read of size 8 at addr ffff8801c8e35738 by task syzkaller815102/3327 [ 28.400874] [ 28.402474] CPU: 0 PID: 3327 Comm: syzkaller815102 Not tainted 4.9.76-gf0f6293 #22 [ 28.410147] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.419475] ffff8801cb7cf870 ffffffff81d93149 ffffea0007238d00 ffff8801c8e35738 [ 28.427454] 0000000000000000 ffff8801c8e35738 ffff8801c8e35738 ffff8801cb7cf8a8 [ 28.435433] ffffffff8153cb43 ffff8801c8e35738 0000000000000008 0000000000000000 [ 28.443414] Call Trace: [ 28.445974] [] dump_stack+0xc1/0x128 [ 28.451310] [] print_address_description+0x73/0x280 [ 28.457947] [] kasan_report+0x275/0x360 [ 28.463544] [] ? __lock_acquire+0x2eff/0x3640 [ 28.469658] [] __asan_report_load8_noabort+0x14/0x20 [ 28.476384] [] __lock_acquire+0x2eff/0x3640 [ 28.482329] [] ? __lock_acquire+0x629/0x3640 [ 28.488361] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.495343] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.502328] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.509313] [] ? mark_held_locks+0xaf/0x100 [ 28.515258] [] ? mutex_lock_nested+0x5e3/0x870 [ 28.521461] [] lock_acquire+0x12e/0x410 [ 28.527054] [] ? remove_wait_queue+0x14/0x40 [ 28.533079] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 28.539364] [] ? remove_wait_queue+0x14/0x40 [ 28.545389] [] remove_wait_queue+0x14/0x40 [ 28.551243] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 28.558239] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 28.565482] [] ? ep_free+0x1b0/0x1b0 [ 28.570817] [] ep_free+0x96/0x1b0 [ 28.575889] [] ? ep_free+0x1b0/0x1b0 [ 28.581224] [] ep_eventpoll_release+0x44/0x60 [ 28.587341] [] __fput+0x28c/0x6e0 [ 28.592419] [] ____fput+0x15/0x20 [ 28.597494] [] task_work_run+0x115/0x190 [ 28.603179] [] do_exit+0x7e7/0x2a40 [ 28.608427] [] ? __pmd_alloc+0x410/0x410 [ 28.614105] [] ? release_task+0x1240/0x1240 [ 28.620048] [] ? __do_page_fault+0x5ec/0xd40 [ 28.626088] [] ? up_read+0x1a/0x40 [ 28.631257] [] ? __do_page_fault+0x3bd/0xd40 [ 28.637286] [] do_group_exit+0x108/0x320 [ 28.642968] [] ? do_group_exit+0x320/0x320 [ 28.648822] [] SyS_exit_group+0x1d/0x20 [ 28.654418] [] do_fast_syscall_32+0x2f7/0x890 [ 28.660534] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 28.667175] [] entry_SYSENTER_compat+0x74/0x83 [ 28.673375] [ 28.674971] Allocated by task 3327: [ 28.678568] save_stack_trace+0x16/0x20 [ 28.682512] save_stack+0x43/0xd0 [ 28.685934] kasan_kmalloc+0xad/0xe0 [ 28.689616] kmem_cache_alloc_trace+0xfb/0x2a0 [ 28.694169] binder_get_thread+0x15d/0x750 [ 28.698385] binder_poll+0x4a/0x210 [ 28.701983] SyS_epoll_ctl+0x11d7/0x2190 [ 28.706012] do_fast_syscall_32+0x2f7/0x890 [ 28.710303] entry_SYSENTER_compat+0x74/0x83 [ 28.714678] [ 28.716274] Freed by task 3327: [ 28.719523] save_stack_trace+0x16/0x20 [ 28.723466] save_stack+0x43/0xd0 [ 28.726899] kasan_slab_free+0x72/0xc0 [ 28.730753] kfree+0x103/0x300 [ 28.733914] binder_thread_dec_tmpref+0x1cc/0x240 [ 28.738738] binder_thread_release+0x27d/0x540 [ 28.743288] binder_ioctl+0x9c0/0x11b0 [ 28.747146] compat_SyS_ioctl+0x15f/0x2050 [ 28.751353] do_fast_syscall_32+0x2f7/0x890 [ 28.755650] entry_SYSENTER_compat+0x74/0x83 [ 28.760023] [ 28.761621] The buggy address belongs to the object at ffff8801c8e35680 [ 28.761621] which belongs to the cache kmalloc-512 of size 512 [ 28.774249] The buggy address is located 184 bytes inside of [ 28.774249] 512-byte region [ffff8801c8e35680, ffff8801c8e35880) [ 28.786090] The buggy address belongs to the page: [ 28.790989] page:ffffea0007238d00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 28.801162] flags: 0x8000000000004080(slab|head) [ 28.805885] page dumped because: kasan: bad access detected [ 28.811563] [ 28.813168] Memory state around the buggy address: [ 28.818064] ffff8801c8e35600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 28.825393] ffff8801c8e35680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.832720] >ffff8801c8e35700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.840049] ^ [ 28.845207] ffff8801c8e35780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.852535] ffff8801c8e35800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.859861] ================================================================== [ 28.867188] Disabling lock debugging due to kernel taint [ 28.872609] Kernel panic - not syncing: panic_on_warn set ... [ 28.872609] [ 28.879942] CPU: 0 PID: 3327 Comm: syzkaller815102 Tainted: G B 4.9.76-gf0f6293 #22 [ 28.888832] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.898175] ffff8801cb7cf7c8 ffffffff81d93149 ffffffff84195c17 ffff8801cb7cf8a0 [ 28.906146] 0000000000000000 ffff8801c8e35738 ffff8801c8e35738 ffff8801cb7cf890 [ 28.914128] ffffffff8142e371 0000000041b58ab3 ffffffff84189678 ffffffff8142e1b5 [ 28.922111] Call Trace: [ 28.924671] [] dump_stack+0xc1/0x128 [ 28.930005] [] panic+0x1bc/0x3a8 [ 28.934991] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 28.943193] [] ? add_taint+0x40/0x50 [ 28.948527] [] kasan_end_report+0x50/0x50 [ 28.954293] [] kasan_report+0x167/0x360 [ 28.959888] [] ? __lock_acquire+0x2eff/0x3640 [ 28.966013] [] __asan_report_load8_noabort+0x14/0x20 [ 28.972734] [] __lock_acquire+0x2eff/0x3640 [ 28.978673] [] ? __lock_acquire+0x629/0x3640 [ 28.984699] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.991690] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 28.998674] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.005655] [] ? mark_held_locks+0xaf/0x100 [ 29.011596] [] ? mutex_lock_nested+0x5e3/0x870 [ 29.017797] [] lock_acquire+0x12e/0x410 [ 29.023401] [] ? remove_wait_queue+0x14/0x40 [ 29.029426] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.035713] [] ? remove_wait_queue+0x14/0x40 [ 29.041741] [] remove_wait_queue+0x14/0x40 [ 29.047597] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 29.054579] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 29.061834] [] ? ep_free+0x1b0/0x1b0 [ 29.067166] [] ep_free+0x96/0x1b0 [ 29.072241] [] ? ep_free+0x1b0/0x1b0 [ 29.077573] [] ep_eventpoll_release+0x44/0x60 [ 29.083691] [] __fput+0x28c/0x6e0 [ 29.088764] [] ____fput+0x15/0x20 [ 29.093844] [] task_work_run+0x115/0x190 [ 29.099529] [] do_exit+0x7e7/0x2a40 [ 29.104775] [] ? __pmd_alloc+0x410/0x410 [ 29.110454] [] ? release_task+0x1240/0x1240 [ 29.116398] [] ? __do_page_fault+0x5ec/0xd40 [ 29.122426] [] ? up_read+0x1a/0x40 [ 29.127585] [] ? __do_page_fault+0x3bd/0xd40 [ 29.133610] [] do_group_exit+0x108/0x320 [ 29.139289] [] ? do_group_exit+0x320/0x320 [ 29.145149] [] SyS_exit_group+0x1d/0x20 [ 29.150742] [] do_fast_syscall_32+0x2f7/0x890 [ 29.156866] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.163503] [] entry_SYSENTER_compat+0x74/0x83 [ 29.170147] Dumping ftrace buffer: [ 29.173656] (ftrace buffer empty) [ 29.177335] Kernel Offset: disabled [ 29.180929] Rebooting in 86400 seconds..