[....] Starting enhanced syslogd: rsyslogd[ 12.337772] audit: type=1400 audit(1519222771.998:4): avc: denied { syslog } for pid=3486 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[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.23' (ECDSA) to the list of known hosts. executing program executing program executing program executing program syzkaller login: [ 20.417767] IPVS: Creating netns size=2536 id=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 21.041051] ================================================================== [ 21.048434] BUG: KASAN: use-after-free in do_raw_spin_lock+0x1ac/0x1e0 [ 21.055073] Read of size 4 at addr ffff8801c812eaa4 by task syzkaller113456/3973 [ 21.062577] [ 21.064175] CPU: 1 PID: 3973 Comm: syzkaller113456 Not tainted 4.9.82-gcdfc8df #37 [ 21.071849] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 21.081178] ffff8801d8fcfc40 ffffffff81d94fc9 ffffea0007204b80 ffff8801c812eaa4 [ 21.089153] 0000000000000000 ffff8801c812eaa4 ffff8801c8e90340 ffff8801d8fcfc78 [ 21.097124] ffffffff8153e213 ffff8801c812eaa4 0000000000000004 0000000000000000 [ 21.105090] Call Trace: [ 21.107654] [] dump_stack+0xc1/0x128 [ 21.112998] [] print_address_description+0x73/0x280 [ 21.119632] [] kasan_report+0x275/0x360 [ 21.125224] [] ? do_raw_spin_lock+0x1ac/0x1e0 [ 21.131337] [] __asan_report_load4_noabort+0x14/0x20 [ 21.138058] [] do_raw_spin_lock+0x1ac/0x1e0 [ 21.143997] [] _raw_spin_lock_irqsave+0x56/0x70 [ 21.150286] [] ? remove_wait_queue+0x14/0x40 [ 21.156314] [] remove_wait_queue+0x14/0x40 [ 21.162169] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 21.169154] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 21.176400] [] ? ep_free+0x1b0/0x1b0 [ 21.181742] [] ep_free+0x96/0x1b0 [ 21.186814] [] ? ep_free+0x1b0/0x1b0 [ 21.192149] [] ep_eventpoll_release+0x44/0x60 [ 21.198278] [] __fput+0x28c/0x6e0 [ 21.203350] [] ____fput+0x15/0x20 [ 21.208426] [] task_work_run+0x115/0x190 [ 21.214113] [] exit_to_usermode_loop+0xfc/0x120 [ 21.220407] [] do_syscall_64+0x370/0x490 [ 21.226097] [] entry_SYSCALL_64_after_swapgs+0x47/0xc5 [ 21.232990] [ 21.234590] Allocated by task 3972: [ 21.238187] save_stack_trace+0x16/0x20 [ 21.242129] save_stack+0x43/0xd0 [ 21.245555] kasan_kmalloc+0xad/0xe0 [ 21.249238] kmem_cache_alloc_trace+0xfb/0x2a0 [ 21.253789] binder_get_thread+0x15d/0x750 [ 21.257992] binder_poll+0x4a/0x210 [ 21.261588] SyS_epoll_ctl+0x11d7/0x2190 [ 21.265616] do_syscall_64+0x1a5/0x490 [ 21.269474] entry_SYSCALL_64_after_swapgs+0x47/0xc5 [ 21.274540] [ 21.276137] Freed by task 3972: [ 21.279387] save_stack_trace+0x16/0x20 [ 21.283336] save_stack+0x43/0xd0 [ 21.286764] kasan_slab_free+0x72/0xc0 [ 21.290623] kfree+0x103/0x300 [ 21.293787] binder_thread_dec_tmpref+0x1cc/0x240 [ 21.298606] binder_thread_release+0x3a7/0x5c0 [ 21.303154] binder_ioctl+0x9c0/0x11b0 [ 21.307011] do_vfs_ioctl+0x1aa/0x1140 [ 21.310867] SyS_ioctl+0x8f/0xc0 [ 21.314199] do_syscall_64+0x1a5/0x490 [ 21.318054] entry_SYSCALL_64_after_swapgs+0x47/0xc5 [ 21.323118] [ 21.324716] The buggy address belongs to the object at ffff8801c812ea00 [ 21.324716] which belongs to the cache kmalloc-512 of size 512 [ 21.337339] The buggy address is located 164 bytes inside of [ 21.337339] 512-byte region [ffff8801c812ea00, ffff8801c812ec00) [ 21.349179] The buggy address belongs to the page: [ 21.354078] page:ffffea0007204b80 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 21.364246] flags: 0x8000000000004080(slab|head) [ 21.368966] page dumped because: kasan: bad access detected [ 21.374641] [ 21.376238] Memory state around the buggy address: [ 21.381136] ffff8801c812e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.388464] ffff8801c812ea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.395793] >ffff8801c812ea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.403117] ^ [ 21.407497] ffff8801c812eb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.414825] ffff8801c812eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.422152] ================================================================== [ 21.429488] Disabling lock debugging due to kernel taint [ 21.434916] Kernel panic - not syncing: panic_on_warn set ... [ 21.434916] [ 21.442255] CPU: 1 PID: 3973 Comm: syzkaller113456 Tainted: G B 4.9.82-gcdfc8df #37 [ 21.451154] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 21.460479] ffff8801d8fcfb98 ffffffff81d94fc9 ffffffff8419777f ffff8801d8fcfc70 [ 21.468451] 0000000000000000 ffff8801c812eaa4 ffff8801c8e90340 ffff8801d8fcfc60 [ 21.476422] ffffffff8142f6c1 0000000041b58ab3 ffffffff8418b1f0 ffffffff8142f505 [ 21.484396] Call Trace: [ 21.486959] [] dump_stack+0xc1/0x128 [ 21.492301] [] panic+0x1bc/0x3a8 [ 21.497289] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 21.505485] [] kasan_end_report+0x50/0x50 [ 21.511252] [] kasan_report+0x167/0x360 [ 21.516846] [] ? do_raw_spin_lock+0x1ac/0x1e0 [ 21.522960] [] __asan_report_load4_noabort+0x14/0x20 [ 21.529681] [] do_raw_spin_lock+0x1ac/0x1e0 [ 21.535621] [] _raw_spin_lock_irqsave+0x56/0x70 [ 21.541907] [] ? remove_wait_queue+0x14/0x40 [ 21.547936] [] remove_wait_queue+0x14/0x40 [ 21.553791] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 21.560771] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 21.568012] [] ? ep_free+0x1b0/0x1b0 [ 21.573342] [] ep_free+0x96/0x1b0 [ 21.578414] [] ? ep_free+0x1b0/0x1b0 [ 21.584289] [] ep_eventpoll_release+0x44/0x60 [ 21.590407] [] __fput+0x28c/0x6e0 [ 21.595476] [] ____fput+0x15/0x20 [ 21.600549] [] task_work_run+0x115/0x190 [ 21.606231] [] exit_to_usermode_loop+0xfc/0x120 [ 21.612517] [] do_syscall_64+0x370/0x490 [ 21.618196] [] entry_SYSCALL_64_after_swapgs+0x47/0xc5 [ 21.625558] Dumping ftrace buffer: [ 21.629066] (ftrace buffer empty) [ 21.632742] Kernel Offset: disabled [ 21.636336] Rebooting in 86400 seconds..