[....] Starting enhanced syslogd: rsyslogd[ 11.554750] audit: type=1400 audit(1513734202.700:4): avc: denied { syslog } for pid=3158 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 'ci-android-49-kasan-gce-5,10.128.0.39' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 33.306840] ================================================================== [ 33.314216] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 33.320847] Read of size 8 at addr ffff8801c85fc338 by task syzkaller268007/3325 [ 33.328339] [ 33.329936] CPU: 1 PID: 3325 Comm: syzkaller268007 Not tainted 4.9.70-gc14c7b3 #110 [ 33.337864] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.350329] ffff8801c89c78e0 ffffffff81d90c49 ffffea0007217f00 ffff8801c85fc338 [ 33.358544] 0000000000000000 ffff8801c85fc338 ffff8801c85fc338 ffff8801c89c7918 [ 33.366491] ffffffff8153a6f3 ffff8801c85fc338 0000000000000008 0000000000000000 [ 33.374434] Call Trace: [ 33.376988] [] dump_stack+0xc1/0x128 [ 33.382319] [] print_address_description+0x73/0x280 [ 33.388954] [] kasan_report+0x275/0x360 [ 33.394540] [] ? __lock_acquire+0x2eff/0x3640 [ 33.400648] [] __asan_report_load8_noabort+0x14/0x20 [ 33.407363] [] __lock_acquire+0x2eff/0x3640 [ 33.413297] [] ? __lock_acquire+0x629/0x3640 [ 33.419323] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.426297] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.433279] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.440253] [] ? mark_held_locks+0xaf/0x100 [ 33.446187] [] ? mutex_lock_nested+0x5e3/0x870 [ 33.452381] [] lock_acquire+0x12e/0x410 [ 33.457968] [] ? remove_wait_queue+0x14/0x40 [ 33.463990] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 33.470284] [] ? remove_wait_queue+0x14/0x40 [ 33.476313] [] remove_wait_queue+0x14/0x40 [ 33.482163] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 33.489139] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 33.496377] [] ? ep_free+0x1b0/0x1b0 [ 33.501704] [] ep_free+0x96/0x1b0 [ 33.506768] [] ? ep_free+0x1b0/0x1b0 [ 33.512096] [] ep_eventpoll_release+0x44/0x60 [ 33.518220] [] __fput+0x28c/0x6e0 [ 33.523300] [] ____fput+0x15/0x20 [ 33.528374] [] task_work_run+0x115/0x190 [ 33.534053] [] do_exit+0x7e7/0x2a40 [ 33.539303] [] ? selinux_file_ioctl+0x355/0x530 [ 33.545585] [] ? release_task+0x1240/0x1240 [ 33.551519] [] ? SyS_epoll_create+0x190/0x190 [ 33.557801] [] ? entry_SYSCALL_64_fastpath+0x5/0xc6 [ 33.564436] [] do_group_exit+0x108/0x320 [ 33.570110] [] SyS_exit_group+0x1d/0x20 [ 33.575695] [] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 33.582235] [ 33.583830] Allocated by task 3325: [ 33.587419] save_stack_trace+0x16/0x20 [ 33.591355] save_stack+0x43/0xd0 [ 33.594771] kasan_kmalloc+0xad/0xe0 [ 33.598447] kmem_cache_alloc_trace+0xfb/0x2a0 [ 33.602991] binder_get_thread+0x15d/0x750 [ 33.607188] binder_poll+0x4a/0x210 [ 33.610778] SyS_epoll_ctl+0x11d7/0x2190 [ 33.614808] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 33.619524] [ 33.621114] Freed by task 3325: [ 33.624354] save_stack_trace+0x16/0x20 [ 33.628288] save_stack+0x43/0xd0 [ 33.631705] kasan_slab_free+0x72/0xc0 [ 33.635553] kfree+0xf0/0x2f0 [ 33.638621] binder_thread_dec_tmpref+0x1cc/0x240 [ 33.643425] binder_thread_release+0x27d/0x540 [ 33.647971] binder_ioctl+0x9c0/0x11b0 [ 33.652694] do_vfs_ioctl+0x1aa/0x1140 [ 33.657070] SyS_ioctl+0x8f/0xc0 [ 33.660398] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 33.665113] [ 33.666705] The buggy address belongs to the object at ffff8801c85fc280 [ 33.666705] which belongs to the cache kmalloc-512 of size 512 [ 33.679329] The buggy address is located 184 bytes inside of [ 33.679329] 512-byte region [ffff8801c85fc280, ffff8801c85fc480) [ 33.691167] The buggy address belongs to the page: [ 33.696064] page:ffffea0007217f00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 33.706216] flags: 0x8000000000004080(slab|head) [ 33.710937] page dumped because: kasan: bad access detected [ 33.716607] [ 33.718198] Memory state around the buggy address: [ 33.723092] ffff8801c85fc200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 33.730416] ffff8801c85fc280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.737740] >ffff8801c85fc300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.745062] ^ [ 33.750212] ffff8801c85fc380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.757536] ffff8801c85fc400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.764864] ================================================================== [ 33.772183] Disabling lock debugging due to kernel taint [ 33.777597] Kernel panic - not syncing: panic_on_warn set ... [ 33.777597] [ 33.784922] CPU: 1 PID: 3325 Comm: syzkaller268007 Tainted: G B 4.9.70-gc14c7b3 #110 [ 33.793892] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.803210] ffff8801c89c7838 ffffffff81d90c49 ffffffff84193817 ffff8801c89c7910 [ 33.811150] 0000000000000000 ffff8801c85fc338 ffff8801c85fc338 ffff8801c89c7900 [ 33.819107] ffffffff8142c481 0000000041b58ab3 ffffffff84187288 ffffffff8142c2c5 [ 33.827046] Call Trace: [ 33.829599] [] dump_stack+0xc1/0x128 [ 33.834926] [] panic+0x1bc/0x3a8 [ 33.839904] [] ? percpu_up_read_preempt_enable.constprop.54+0xd7/0xd7 [ 33.848094] [] ? add_taint+0x40/0x50 [ 33.853422] [] kasan_end_report+0x50/0x50 [ 33.859181] [] kasan_report+0x167/0x360 [ 33.864774] [] ? __lock_acquire+0x2eff/0x3640 [ 33.870882] [] __asan_report_load8_noabort+0x14/0x20 [ 33.877955] [] __lock_acquire+0x2eff/0x3640 [ 33.883891] [] ? __lock_acquire+0x629/0x3640 [ 33.890179] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.897160] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.904138] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 33.911117] [] ? mark_held_locks+0xaf/0x100 [ 33.917053] [] ? mutex_lock_nested+0x5e3/0x870 [ 33.923247] [] lock_acquire+0x12e/0x410 [ 33.928834] [] ? remove_wait_queue+0x14/0x40 [ 33.934856] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 33.941137] [] ? remove_wait_queue+0x14/0x40 [ 33.947158] [] remove_wait_queue+0x14/0x40 [ 33.953004] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 33.959978] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 33.967223] [] ? ep_free+0x1b0/0x1b0 [ 33.972550] [] ep_free+0x96/0x1b0 [ 33.977616] [] ? ep_free+0x1b0/0x1b0 [ 33.982941] [] ep_eventpoll_release+0x44/0x60 [ 33.989053] [] __fput+0x28c/0x6e0 [ 33.994208] [] ____fput+0x15/0x20 [ 33.999274] [] task_work_run+0x115/0x190 [ 34.004950] [] do_exit+0x7e7/0x2a40 [ 34.010194] [] ? selinux_file_ioctl+0x355/0x530 [ 34.016478] [] ? release_task+0x1240/0x1240 [ 34.022412] [] ? SyS_epoll_create+0x190/0x190 [ 34.028523] [] ? entry_SYSCALL_64_fastpath+0x5/0xc6 [ 34.035161] [] do_group_exit+0x108/0x320 [ 34.040842] [] SyS_exit_group+0x1d/0x20 [ 34.046428] [] entry_SYSCALL_64_fastpath+0x23/0xc6 [ 34.053009] Dumping ftrace buffer: [ 34.056511] (ftrace buffer empty) [ 34.060188] Kernel Offset: disabled [ 34.063778] Rebooting in 86400 seconds..