[....] Starting enhanced syslogd: rsyslogd[ 13.286499] audit: type=1400 audit(1517190460.122:4): avc: denied { syslog } for pid=3171 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 '10.128.0.58' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 44.084353] ================================================================== [ 44.091746] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 44.098386] Read of size 8 at addr ffff8801cd160338 by task syzkaller025117/3343 [ 44.105911] [ 44.107515] CPU: 0 PID: 3343 Comm: syzkaller025117 Not tainted 4.9.78-g68d447c #23 [ 44.115193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.124534] ffff8801c821f8e0 ffffffff81d943a9 ffffea0007345800 ffff8801cd160338 [ 44.132512] 0000000000000000 ffff8801cd160338 ffff8801cd160338 ffff8801c821f918 [ 44.140657] ffffffff8153dc23 ffff8801cd160338 0000000000000008 0000000000000000 [ 44.148630] Call Trace: [ 44.151193] [] dump_stack+0xc1/0x128 [ 44.156544] [] print_address_description+0x73/0x280 [ 44.163184] [] kasan_report+0x275/0x360 [ 44.168794] [] ? __lock_acquire+0x2eff/0x3640 [ 44.174913] [] __asan_report_load8_noabort+0x14/0x20 [ 44.181660] [] __lock_acquire+0x2eff/0x3640 [ 44.187614] [] ? __lock_acquire+0x629/0x3640 [ 44.193685] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 44.200673] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 44.207680] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 44.214695] [] ? mark_held_locks+0xaf/0x100 [ 44.220643] [] ? mutex_lock_nested+0x5e3/0x870 [ 44.226849] [] lock_acquire+0x12e/0x410 [ 44.232454] [] ? remove_wait_queue+0x14/0x40 [ 44.238488] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 44.244781] [] ? remove_wait_queue+0x14/0x40 [ 44.250822] [] remove_wait_queue+0x14/0x40 [ 44.256686] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 44.263693] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 44.270947] [] ? ep_free+0x1b0/0x1b0 [ 44.276282] [] ep_free+0x96/0x1b0 [ 44.281358] [] ? ep_free+0x1b0/0x1b0 [ 44.286696] [] ep_eventpoll_release+0x44/0x60 [ 44.292816] [] __fput+0x28c/0x6e0 [ 44.297891] [] ____fput+0x15/0x20 [ 44.302970] [] task_work_run+0x115/0x190 [ 44.308656] [] do_exit+0x7e7/0x2a40 [ 44.313914] [] ? selinux_file_ioctl+0x355/0x530 [ 44.320206] [] ? release_task+0x1240/0x1240 [ 44.326170] [] ? SyS_epoll_create+0x190/0x190 [ 44.332291] [] ? entry_SYSCALL_64_fastpath+0x5/0xe8 [ 44.338936] [] do_group_exit+0x108/0x320 [ 44.344622] [] SyS_exit_group+0x1d/0x20 [ 44.350217] [] entry_SYSCALL_64_fastpath+0x29/0xe8 [ 44.356768] [ 44.358378] Allocated by task 3343: [ 44.361978] save_stack_trace+0x16/0x20 [ 44.365927] save_stack+0x43/0xd0 [ 44.369348] kasan_kmalloc+0xad/0xe0 [ 44.373033] kmem_cache_alloc_trace+0xfb/0x2a0 [ 44.377589] binder_get_thread+0x15d/0x750 [ 44.381793] binder_poll+0x4a/0x210 [ 44.385392] SyS_epoll_ctl+0x11d7/0x2190 [ 44.389436] entry_SYSCALL_64_fastpath+0x29/0xe8 [ 44.394168] [ 44.395764] Freed by task 3343: [ 44.399014] save_stack_trace+0x16/0x20 [ 44.402960] save_stack+0x43/0xd0 [ 44.406382] kasan_slab_free+0x72/0xc0 [ 44.410240] kfree+0x103/0x300 [ 44.413405] binder_thread_dec_tmpref+0x1cc/0x240 [ 44.418227] binder_thread_release+0x27d/0x540 [ 44.422790] binder_ioctl+0x9c0/0x11b0 [ 44.426736] do_vfs_ioctl+0x1aa/0x1140 [ 44.430600] SyS_ioctl+0x8f/0xc0 [ 44.433939] entry_SYSCALL_64_fastpath+0x29/0xe8 [ 44.438680] [ 44.440277] The buggy address belongs to the object at ffff8801cd160280 [ 44.440277] which belongs to the cache kmalloc-512 of size 512 [ 44.452904] The buggy address is located 184 bytes inside of [ 44.452904] 512-byte region [ffff8801cd160280, ffff8801cd160480) [ 44.464834] The buggy address belongs to the page: [ 44.469737] page:ffffea0007345800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 44.479918] flags: 0x8000000000004080(slab|head) [ 44.484642] page dumped because: kasan: bad access detected [ 44.490321] [ 44.491921] Memory state around the buggy address: [ 44.496833] ffff8801cd160200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 44.504163] ffff8801cd160280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.511505] >ffff8801cd160300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.518836] ^ [ 44.523999] ffff8801cd160380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.531326] ffff8801cd160400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 44.538659] ================================================================== [ 44.546073] Disabling lock debugging due to kernel taint [ 44.551491] Kernel panic - not syncing: panic_on_warn set ... [ 44.551491] [ 44.558838] CPU: 0 PID: 3343 Comm: syzkaller025117 Tainted: G B 4.9.78-g68d447c #23 [ 44.567731] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.577059] ffff8801c821f838 ffffffff81d943a9 ffffffff841971bf ffff8801c821f910 [ 44.585051] 0000000000000000 ffff8801cd160338 ffff8801cd160338 ffff8801c821f900 [ 44.593023] ffffffff8142f451 0000000041b58ab3 ffffffff8418ac30 ffffffff8142f295 [ 44.600994] Call Trace: [ 44.603560] [] dump_stack+0xc1/0x128 [ 44.608896] [] panic+0x1bc/0x3a8 [ 44.613904] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 44.622122] [] ? add_taint+0x40/0x50 [ 44.627477] [] kasan_end_report+0x50/0x50 [ 44.633259] [] kasan_report+0x167/0x360 [ 44.638857] [] ? __lock_acquire+0x2eff/0x3640 [ 44.644988] [] __asan_report_load8_noabort+0x14/0x20 [ 44.651715] [] __lock_acquire+0x2eff/0x3640 [ 44.657663] [] ? __lock_acquire+0x629/0x3640 [ 44.663692] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 44.670678] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 44.677662] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 44.684649] [] ? mark_held_locks+0xaf/0x100 [ 44.690597] [] ? mutex_lock_nested+0x5e3/0x870 [ 44.696801] [] lock_acquire+0x12e/0x410 [ 44.702404] [] ? remove_wait_queue+0x14/0x40 [ 44.708452] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 44.714743] [] ? remove_wait_queue+0x14/0x40 [ 44.720771] [] remove_wait_queue+0x14/0x40 [ 44.726642] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 44.733627] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 44.740868] [] ? ep_free+0x1b0/0x1b0 [ 44.746209] [] ep_free+0x96/0x1b0 [ 44.751283] [] ? ep_free+0x1b0/0x1b0 [ 44.756619] [] ep_eventpoll_release+0x44/0x60 [ 44.762760] [] __fput+0x28c/0x6e0 [ 44.767843] [] ____fput+0x15/0x20 [ 44.772920] [] task_work_run+0x115/0x190 [ 44.778624] [] do_exit+0x7e7/0x2a40 [ 44.783876] [] ? selinux_file_ioctl+0x355/0x530 [ 44.790164] [] ? release_task+0x1240/0x1240 [ 44.796107] [] ? SyS_epoll_create+0x190/0x190 [ 44.802227] [] ? entry_SYSCALL_64_fastpath+0x5/0xe8 [ 44.808867] [] do_group_exit+0x108/0x320 [ 44.814562] [] SyS_exit_group+0x1d/0x20 [ 44.820166] [] entry_SYSCALL_64_fastpath+0x29/0xe8 [ 44.827140] Dumping ftrace buffer: [ 44.830665] (ftrace buffer empty) [ 44.834346] Kernel Offset: disabled [ 44.837945] Rebooting in 86400 seconds..