[....] Starting enhanced syslogd: rsyslogd[ 10.981556] audit: type=1400 audit(1515272734.667:4): avc: denied { syslog } for pid=3180 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 '10.128.15.200' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 20.332533] ================================================================== [ 20.333693] BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 [ 20.334573] Read of size 8 at addr ffff8801c9041738 by task syzkaller426750/3329 [ 20.335570] [ 20.335802] CPU: 1 PID: 3329 Comm: syzkaller426750 Not tainted 4.9.75-g06fe41f #6 [ 20.336860] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 20.338081] ffff8801caa978e0 ffffffff81d93049 ffffea0007241000 ffff8801c9041738 [ 20.339224] 0000000000000000 ffff8801c9041738 ffff8801c9041738 ffff8801caa97918 [ 20.340385] ffffffff8153ca53 ffff8801c9041738 0000000000000008 0000000000000000 [ 20.341533] Call Trace: [ 20.341915] [] dump_stack+0xc1/0x128 [ 20.342674] [] print_address_description+0x73/0x280 [ 20.343580] [] kasan_report+0x275/0x360 [ 20.344329] [] ? __lock_acquire+0x2eff/0x3640 [ 20.345138] [] __asan_report_load8_noabort+0x14/0x20 [ 20.346054] [] __lock_acquire+0x2eff/0x3640 [ 20.346840] [] ? __lock_acquire+0x629/0x3640 [ 20.347648] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.348569] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.349488] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.350434] [] ? mark_held_locks+0xaf/0x100 [ 20.351242] [] ? mutex_lock_nested+0x5e3/0x870 [ 20.352095] [] lock_acquire+0x12e/0x410 [ 20.354090] [] ? remove_wait_queue+0x14/0x40 [ 20.360113] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 20.366398] [] ? remove_wait_queue+0x14/0x40 [ 20.372425] [] remove_wait_queue+0x14/0x40 [ 20.378276] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 20.385255] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 20.392504] [] ? ep_free+0x1b0/0x1b0 [ 20.397836] [] ep_free+0x96/0x1b0 [ 20.402914] [] ? ep_free+0x1b0/0x1b0 [ 20.408244] [] ep_eventpoll_release+0x44/0x60 [ 20.414359] [] __fput+0x28c/0x6e0 [ 20.419426] [] ____fput+0x15/0x20 [ 20.424497] [] task_work_run+0x115/0x190 [ 20.430175] [] do_exit+0x7e7/0x2a40 [ 20.435422] [] ? selinux_file_ioctl+0x355/0x530 [ 20.441711] [] ? release_task+0x1240/0x1240 [ 20.447655] [] ? SyS_epoll_create+0x190/0x190 [ 20.453769] [] ? entry_SYSCALL_64_fastpath+0x5/0xe2 [ 20.460411] [] do_group_exit+0x108/0x320 [ 20.466091] [] SyS_exit_group+0x1d/0x20 [ 20.471682] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 20.478244] [ 20.479846] Allocated by task 3329: [ 20.483445] save_stack_trace+0x16/0x20 [ 20.487390] save_stack+0x43/0xd0 [ 20.490809] kasan_kmalloc+0xad/0xe0 [ 20.494495] kmem_cache_alloc_trace+0xfb/0x2a0 [ 20.499067] binder_get_thread+0x15d/0x750 [ 20.503288] binder_poll+0x4a/0x210 [ 20.506897] SyS_epoll_ctl+0x11d7/0x2190 [ 20.510940] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 20.515662] [ 20.517265] Freed by task 3329: [ 20.520520] save_stack_trace+0x16/0x20 [ 20.524467] save_stack+0x43/0xd0 [ 20.527888] kasan_slab_free+0x72/0xc0 [ 20.531741] kfree+0x103/0x300 [ 20.534906] binder_thread_dec_tmpref+0x1cc/0x240 [ 20.539714] binder_thread_release+0x27d/0x540 [ 20.544269] binder_ioctl+0x9c0/0x11b0 [ 20.548122] do_vfs_ioctl+0x1aa/0x1140 [ 20.551975] SyS_ioctl+0x8f/0xc0 [ 20.555312] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 20.560043] [ 20.561641] The buggy address belongs to the object at ffff8801c9041680 [ 20.561641] which belongs to the cache kmalloc-512 of size 512 [ 20.574274] The buggy address is located 184 bytes inside of [ 20.574274] 512-byte region [ffff8801c9041680, ffff8801c9041880) [ 20.586116] The buggy address belongs to the page: [ 20.591017] page:ffffea0007241000 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 20.601176] flags: 0x8000000000004080(slab|head) [ 20.605894] page dumped because: kasan: bad access detected [ 20.611571] [ 20.613166] Memory state around the buggy address: [ 20.618062] ffff8801c9041600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 20.625389] ffff8801c9041680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.632745] >ffff8801c9041700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.640080] ^ [ 20.645250] ffff8801c9041780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.652583] ffff8801c9041800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 20.659909] ================================================================== [ 20.667234] Disabling lock debugging due to kernel taint [ 20.672650] Kernel panic - not syncing: panic_on_warn set ... [ 20.672650] [ 20.679979] CPU: 1 PID: 3329 Comm: syzkaller426750 Tainted: G B 4.9.75-g06fe41f #6 [ 20.688783] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 20.698120] ffff8801caa97838 ffffffff81d93049 ffffffff84195be7 ffff8801caa97910 [ 20.706075] 0000000000000000 ffff8801c9041738 ffff8801c9041738 ffff8801caa97900 [ 20.714051] ffffffff8142e281 0000000041b58ab3 ffffffff84189648 ffffffff8142e0c5 [ 20.722010] Call Trace: [ 20.724570] [] dump_stack+0xc1/0x128 [ 20.729906] [] panic+0x1bc/0x3a8 [ 20.734889] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 20.743087] [] ? add_taint+0x40/0x50 [ 20.748415] [] kasan_end_report+0x50/0x50 [ 20.754181] [] kasan_report+0x167/0x360 [ 20.759781] [] ? __lock_acquire+0x2eff/0x3640 [ 20.765892] [] __asan_report_load8_noabort+0x14/0x20 [ 20.772612] [] __lock_acquire+0x2eff/0x3640 [ 20.778551] [] ? __lock_acquire+0x629/0x3640 [ 20.784580] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.791559] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.798541] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 20.805526] [] ? mark_held_locks+0xaf/0x100 [ 20.811467] [] ? mutex_lock_nested+0x5e3/0x870 [ 20.817666] [] lock_acquire+0x12e/0x410 [ 20.823256] [] ? remove_wait_queue+0x14/0x40 [ 20.829280] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 20.835581] [] ? remove_wait_queue+0x14/0x40 [ 20.841607] [] remove_wait_queue+0x14/0x40 [ 20.847462] [] ep_unregister_pollwait.isra.6+0xaf/0x240 [ 20.854441] [] ? ep_unregister_pollwait.isra.6+0x12a/0x240 [ 20.861680] [] ? ep_free+0x1b0/0x1b0 [ 20.867022] [] ep_free+0x96/0x1b0 [ 20.872090] [] ? ep_free+0x1b0/0x1b0 [ 20.877419] [] ep_eventpoll_release+0x44/0x60 [ 20.883533] [] __fput+0x28c/0x6e0 [ 20.888610] [] ____fput+0x15/0x20 [ 20.893685] [] task_work_run+0x115/0x190 [ 20.899368] [] do_exit+0x7e7/0x2a40 [ 20.904616] [] ? selinux_file_ioctl+0x355/0x530 [ 20.910902] [] ? release_task+0x1240/0x1240 [ 20.916849] [] ? SyS_epoll_create+0x190/0x190 [ 20.922965] [] ? entry_SYSCALL_64_fastpath+0x5/0xe2 [ 20.929598] [] do_group_exit+0x108/0x320 [ 20.935275] [] SyS_exit_group+0x1d/0x20 [ 20.940867] [] entry_SYSCALL_64_fastpath+0x23/0xe2 [ 20.947458] Dumping ftrace buffer: [ 20.950968] (ftrace buffer empty) [ 20.954644] Kernel Offset: disabled [ 20.958236] Rebooting in 86400 seconds..