[....] Starting enhanced syslogd: rsyslogd[ 11.999848] audit: type=1400 audit(1513704257.066:4): avc: denied { syslog } for pid=3159 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 'ci-android-49-kasan-gce-1,10.128.15.192' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 19.110998] ================================================================== [ 19.118373] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 19.125002] Read of size 8 at addr ffff8801c9a09238 by task syzkaller039512/3310 [ 19.132499] [ 19.134092] CPU: 1 PID: 3310 Comm: syzkaller039512 Not tainted 4.9.70-gc14c7b3 #110 [ 19.141845] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.151171] ffff8801c9ad78e0 ffffffff81d90c49 ffffea0007268200 ffff8801c9a09238 [ 19.159115] 0000000000000000 ffff8801c9a09238 ffff8801c9a09238 ffff8801c9ad7918 [ 19.167056] ffffffff8153a6f3 ffff8801c9a09238 0000000000000008 0000000000000000 [ 19.174998] Call Trace: [ 19.177553] [] dump_stack+0xc1/0x128 [ 19.182881] [] print_address_description+0x73/0x280 [ 19.189508] [] kasan_report+0x275/0x360 [ 19.195097] [] ? __lock_acquire+0x2eff/0x3640 [ 19.201207] [] __asan_report_load8_noabort+0x14/0x20 [ 19.207930] [] __lock_acquire+0x2eff/0x3640 [ 19.213870] [] ? __lock_acquire+0x629/0x3640 [ 19.219890] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.226866] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.233843] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.240819] [] ? mark_held_locks+0xaf/0x100 [ 19.246754] [] ? mutex_lock_nested+0x5e3/0x870 [ 19.252950] [] lock_acquire+0x12e/0x410 [ 19.258538] [] ? remove_wait_queue+0x14/0x40 [ 19.264562] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 19.270845] [] ? remove_wait_queue+0x14/0x40 [ 19.276866] [] remove_wait_queue+0x14/0x40 [ 19.282715] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 19.289690] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 19.296928] [] ? ep_free+0x1b0/0x1b0 [ 19.302251] [] ep_free+0x96/0x1b0 [ 19.307317] [] ? ep_free+0x1b0/0x1b0 [ 19.312645] [] ep_eventpoll_release+0x44/0x60 [ 19.318753] [] __fput+0x28c/0x6e0 [ 19.323821] [] ____fput+0x15/0x20 [ 19.328921] [] task_work_run+0x115/0x190 [ 19.334598] [] do_exit+0x7e7/0x2a40 [ 19.339841] [] ? selinux_file_ioctl+0x355/0x530 [ 19.346127] [] ? release_task+0x1240/0x1240 [ 19.352070] [] ? SyS_epoll_create+0x190/0x190 [ 19.358184] [] ? entry_SYSCALL_64_fastpath+0x5/0xc6 [ 19.364812] [] do_group_exit+0x108/0x320 [ 19.370487] [] SyS_exit_group+0x1d/0x20 [ 19.376077] [] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.382617] [ 19.384207] Allocated by task 3310: [ 19.387797] save_stack_trace+0x16/0x20 [ 19.391734] save_stack+0x43/0xd0 [ 19.395150] kasan_kmalloc+0xad/0xe0 [ 19.398827] kmem_cache_alloc_trace+0xfb/0x2a0 [ 19.403374] binder_get_thread+0x15d/0x750 [ 19.407571] binder_poll+0x4a/0x210 [ 19.411160] SyS_epoll_ctl+0x11d7/0x2190 [ 19.415182] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.419896] [ 19.421490] Freed by task 3310: [ 19.424735] save_stack_trace+0x16/0x20 [ 19.428672] save_stack+0x43/0xd0 [ 19.432088] kasan_slab_free+0x72/0xc0 [ 19.435940] kfree+0xf0/0x2f0 [ 19.439014] binder_thread_dec_tmpref+0x1cc/0x240 [ 19.443817] binder_thread_release+0x27d/0x540 [ 19.448362] binder_ioctl+0x9c0/0x11b0 [ 19.452213] do_vfs_ioctl+0x1aa/0x1140 [ 19.456068] SyS_ioctl+0x8f/0xc0 [ 19.459398] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.464111] [ 19.465702] The buggy address belongs to the object at ffff8801c9a09180 [ 19.465702] which belongs to the cache kmalloc-512 of size 512 [ 19.478320] The buggy address is located 184 bytes inside of [ 19.478320] 512-byte region [ffff8801c9a09180, ffff8801c9a09380) [ 19.490161] The buggy address belongs to the page: [ 19.495056] page:ffffea0007268200 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 19.505207] flags: 0x8000000000004080(slab|head) [ 19.509920] page dumped because: kasan: bad access detected [ 19.515590] [ 19.517183] Memory state around the buggy address: [ 19.522073] ffff8801c9a09100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 19.529393] ffff8801c9a09180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.536714] >ffff8801c9a09200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.544034] ^ [ 19.549187] ffff8801c9a09280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.556507] ffff8801c9a09300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 19.563827] ================================================================== [ 19.571145] Disabling lock debugging due to kernel taint [ 19.576558] Kernel panic - not syncing: panic_on_warn set ... [ 19.576558] [ 19.583884] CPU: 1 PID: 3310 Comm: syzkaller039512 Tainted: G B 4.9.70-gc14c7b3 #110 [ 19.592875] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.602201] ffff8801c9ad7838 ffffffff81d90c49 ffffffff84193817 ffff8801c9ad7910 [ 19.610149] 0000000000000000 ffff8801c9a09238 ffff8801c9a09238 ffff8801c9ad7900 [ 19.618095] ffffffff8142c481 0000000041b58ab3 ffffffff84187288 ffffffff8142c2c5 [ 19.626035] Call Trace: [ 19.628588] [] dump_stack+0xc1/0x128 [ 19.633918] [] panic+0x1bc/0x3a8 [ 19.638896] [] ? percpu_up_read_preempt_enable.constprop.54+0xd7/0xd7 [ 19.647090] [] ? add_taint+0x40/0x50 [ 19.652414] [] kasan_end_report+0x50/0x50 [ 19.658175] [] kasan_report+0x167/0x360 [ 19.663760] [] ? __lock_acquire+0x2eff/0x3640 [ 19.669868] [] __asan_report_load8_noabort+0x14/0x20 [ 19.676582] [] __lock_acquire+0x2eff/0x3640 [ 19.682514] [] ? __lock_acquire+0x629/0x3640 [ 19.688541] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.695516] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.702492] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 19.709469] [] ? mark_held_locks+0xaf/0x100 [ 19.715403] [] ? mutex_lock_nested+0x5e3/0x870 [ 19.721603] [] lock_acquire+0x12e/0x410 [ 19.727191] [] ? remove_wait_queue+0x14/0x40 [ 19.733213] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 19.739495] [] ? remove_wait_queue+0x14/0x40 [ 19.745515] [] remove_wait_queue+0x14/0x40 [ 19.751361] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 19.758337] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 19.765570] [] ? ep_free+0x1b0/0x1b0 [ 19.770896] [] ep_free+0x96/0x1b0 [ 19.775961] [] ? ep_free+0x1b0/0x1b0 [ 19.781287] [] ep_eventpoll_release+0x44/0x60 [ 19.787393] [] __fput+0x28c/0x6e0 [ 19.792458] [] ____fput+0x15/0x20 [ 19.797526] [] task_work_run+0x115/0x190 [ 19.803200] [] do_exit+0x7e7/0x2a40 [ 19.808441] [] ? selinux_file_ioctl+0x355/0x530 [ 19.814723] [] ? release_task+0x1240/0x1240 [ 19.820658] [] ? SyS_epoll_create+0x190/0x190 [ 19.826767] [] ? entry_SYSCALL_64_fastpath+0x5/0xc6 [ 19.833396] [] do_group_exit+0x108/0x320 [ 19.839072] [] SyS_exit_group+0x1d/0x20 [ 19.844659] [] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 19.851628] Dumping ftrace buffer: [ 19.855140] (ftrace buffer empty) [ 19.858816] Kernel Offset: disabled [ 19.862406] Rebooting in 86400 seconds..