[....] Starting enhanced syslogd: rsyslogd[ 11.414110] audit: type=1400 audit(1516493789.827:4): avc: denied { syslog } for pid=3176 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 file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.15.193' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 syzkaller login: [ 87.774499] IPVS: Creating netns size=2536 id=1 RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" RTNETLINK answers: Operation not supported Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" [ 88.236678] audit: type=1400 audit(1516493866.647:5): avc: denied { sys_admin } for pid=3375 comm="syzkaller724721" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 executing program [ 88.278595] audit: type=1400 audit(1516493866.697:6): avc: denied { sys_chroot } for pid=3587 comm="syzkaller724721" capability=18 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 executing program [ 88.380073] audit: type=1400 audit(1516493866.797:7): avc: denied { dac_override } for pid=3587 comm="syzkaller724721" capability=1 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=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 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 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 INIT: Id "6" respawning too fast: disabled for 5 minutes INIT: Id "2" respawning too fast: disabled for 5 minutes INIT: Id "4" respawning too fast: disabled for 5 minutes INIT: Id "3" respawning too fast: disabled for 5 minutes INIT: Id "1" respawning too fast: disabled for 5 minutes INIT: Id "5" respawning too fast: disabled for 5 minutes 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 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 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 [ 130.349032] random: crng init done 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 [ 136.188128] ================================================================== [ 136.195546] BUG: KASAN: use-after-free in link_path_walk+0x104f/0x1220 [ 136.202186] Read of size 4 at addr ffff8801cde66dc0 by task syzkaller724721/5985 [ 136.209684] [ 136.211283] CPU: 1 PID: 5985 Comm: syzkaller724721 Not tainted 4.9.77-ge12a9c4 #27 [ 136.218956] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 136.228279] ffff8801cf6f7900 ffffffff81d941c9 ffffea0007379980 ffff8801cde66dc0 [ 136.236249] 0000000000000000 ffff8801cde66dc0 ffff8801cf6f7cc0 ffff8801cf6f7938 [ 136.244245] ffffffff8153db93 ffff8801cde66dc0 0000000000000004 0000000000000000 [ 136.252234] Call Trace: [ 136.254795] [] dump_stack+0xc1/0x128 [ 136.260132] [] print_address_description+0x73/0x280 [ 136.266767] [] kasan_report+0x275/0x360 [ 136.272359] [] ? link_path_walk+0x104f/0x1220 [ 136.278476] [] __asan_report_load4_noabort+0x14/0x20 [ 136.285216] [] link_path_walk+0x104f/0x1220 [ 136.291156] [] ? walk_component+0xfc0/0xfc0 [ 136.297098] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 136.303909] [] ? lockdep_init_map+0xe4/0x5c0 [ 136.309936] [] path_lookupat+0x6a/0x3f0 [ 136.315528] [] path_openat+0x19c0/0x2910 [ 136.321207] [] ? save_stack_trace+0x16/0x20 [ 136.327147] [] ? kasan_kmalloc+0xad/0xe0 [ 136.332838] [] ? kmem_cache_alloc+0xba/0x290 [ 136.338866] [] ? getname+0x19/0x20 [ 136.344023] [] ? do_sys_open+0x21d/0x4c0 [ 136.349705] [] ? compat_SyS_openat+0x2d/0x40 [ 136.355735] [] ? path_lookupat+0x3f0/0x3f0 [ 136.361603] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 136.368589] [] ? __lock_is_held+0xa1/0xf0 [ 136.374357] [] do_filp_open+0x197/0x290 [ 136.379947] [] ? may_open_dev+0xe0/0xe0 [ 136.385542] [] ? _raw_spin_unlock+0x2c/0x50 [ 136.391481] [] ? __alloc_fd+0x1d7/0x510 [ 136.397074] [] do_sys_open+0x352/0x4c0 [ 136.402581] [] ? filp_open+0x70/0x70 [ 136.407915] [] compat_SyS_openat+0x2d/0x40 [ 136.413767] [] ? compat_SyS_open+0x40/0x40 [ 136.419619] [] do_fast_syscall_32+0x2f7/0x890 [ 136.425732] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 136.432369] [] entry_SYSENTER_compat+0x74/0x83 [ 136.438568] [ 136.440165] Allocated by task 5983: [ 136.443762] save_stack_trace+0x16/0x20 [ 136.447704] save_stack+0x43/0xd0 [ 136.451138] kasan_kmalloc+0xad/0xe0 [ 136.454822] kasan_slab_alloc+0x12/0x20 [ 136.458777] kmem_cache_alloc+0xba/0x290 [ 136.462808] __d_alloc+0x2e/0x8f0 [ 136.466228] d_make_root+0x3f/0x80 [ 136.469738] ramfs_fill_super+0x35f/0x4a0 [ 136.473855] mount_nodev+0x59/0x100 [ 136.477451] ramfs_mount+0x2c/0x40 [ 136.480959] mount_fs+0x27f/0x350 [ 136.484381] vfs_kern_mount.part.21+0xd0/0x3e0 [ 136.488932] do_mount+0x3e1/0x28b0 [ 136.492441] compat_SyS_mount+0xd0/0x1070 [ 136.496557] do_fast_syscall_32+0x2f7/0x890 [ 136.500846] entry_SYSENTER_compat+0x74/0x83 [ 136.505221] [ 136.506819] Freed by task 5983: [ 136.510070] save_stack_trace+0x16/0x20 [ 136.514014] save_stack+0x43/0xd0 [ 136.517437] kasan_slab_free+0x72/0xc0 [ 136.521291] kmem_cache_free+0xc7/0x300 [ 136.525236] dentry_free+0xd5/0x150 [ 136.528831] __dentry_kill+0x343/0x480 [ 136.532689] dput.part.23+0x680/0x7b0 [ 136.536458] do_one_tree+0x43/0x50 [ 136.539969] shrink_dcache_for_umount+0x67/0x160 [ 136.544701] generic_shutdown_super+0x6d/0x340 [ 136.549252] kill_litter_super+0x72/0x90 [ 136.553291] ramfs_kill_sb+0x3f/0x50 [ 136.556976] deactivate_locked_super+0x88/0xd0 [ 136.561527] deactivate_super+0x91/0xd0 [ 136.565470] cleanup_mnt+0xb2/0x160 [ 136.569067] __cleanup_mnt+0x16/0x20 [ 136.572761] task_work_run+0x115/0x190 [ 136.576616] exit_to_usermode_loop+0xfc/0x120 [ 136.581080] do_fast_syscall_32+0x5de/0x890 [ 136.585377] entry_SYSENTER_compat+0x74/0x83 [ 136.589752] [ 136.591350] The buggy address belongs to the object at ffff8801cde66dc0 [ 136.591350] which belongs to the cache dentry of size 288 [ 136.603634] The buggy address is located 0 bytes inside of [ 136.603634] 288-byte region [ffff8801cde66dc0, ffff8801cde66ee0) [ 136.615299] The buggy address belongs to the page: [ 136.620199] page:ffffea0007379980 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 136.630362] flags: 0x8000000000004080(slab|head) [ 136.635082] page dumped because: kasan: bad access detected [ 136.640760] [ 136.642358] Memory state around the buggy address: [ 136.647257] ffff8801cde66c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 136.654597] ffff8801cde66d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 136.661932] >ffff8801cde66d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 136.669268] ^ [ 136.674696] ffff8801cde66e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 136.682032] ffff8801cde66e80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 136.689358] ================================================================== [ 136.696684] Disabling lock debugging due to kernel taint [ 136.702822] Kernel panic - not syncing: panic_on_warn set ... [ 136.702822] [ 136.710174] CPU: 1 PID: 5985 Comm: syzkaller724721 Tainted: G B 4.9.77-ge12a9c4 #27 [ 136.719069] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 136.728420] ffff8801cf6f7858 ffffffff81d941c9 ffffffff841970ff ffff8801cf6f7930 [ 136.736442] 0000000000000000 ffff8801cde66dc0 ffff8801cf6f7cc0 ffff8801cf6f7920 [ 136.744426] ffffffff8142f3c1 0000000041b58ab3 ffffffff8418ab70 ffffffff8142f205 [ 136.752397] Call Trace: [ 136.754972] [] dump_stack+0xc1/0x128 [ 136.760330] [] panic+0x1bc/0x3a8 [ 136.765329] [] ? percpu_up_read_preempt_enable.constprop.53+0xd7/0xd7 [ 136.773529] [] ? preempt_schedule+0x25/0x30 [ 136.779479] [] ? ___preempt_schedule+0x16/0x18 [ 136.785683] [] kasan_end_report+0x50/0x50 [ 136.791450] [] kasan_report+0x167/0x360 [ 136.797044] [] ? link_path_walk+0x104f/0x1220 [ 136.803158] [] __asan_report_load4_noabort+0x14/0x20 [ 136.809878] [] link_path_walk+0x104f/0x1220 [ 136.815816] [] ? walk_component+0xfc0/0xfc0 [ 136.821760] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 136.828568] [] ? lockdep_init_map+0xe4/0x5c0 [ 136.834597] [] path_lookupat+0x6a/0x3f0 [ 136.840207] [] path_openat+0x19c0/0x2910 [ 136.845891] [] ? save_stack_trace+0x16/0x20 [ 136.851832] [] ? kasan_kmalloc+0xad/0xe0 [ 136.857525] [] ? kmem_cache_alloc+0xba/0x290 [ 136.863556] [] ? getname+0x19/0x20 [ 136.868719] [] ? do_sys_open+0x21d/0x4c0 [ 136.874403] [] ? compat_SyS_openat+0x2d/0x40 [ 136.880431] [] ? path_lookupat+0x3f0/0x3f0 [ 136.886288] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 136.893270] [] ? __lock_is_held+0xa1/0xf0 [ 136.899040] [] do_filp_open+0x197/0x290 [ 136.904641] [] ? may_open_dev+0xe0/0xe0 [ 136.910235] [] ? _raw_spin_unlock+0x2c/0x50 [ 136.916179] [] ? __alloc_fd+0x1d7/0x510 [ 136.921773] [] do_sys_open+0x352/0x4c0 [ 136.927286] [] ? filp_open+0x70/0x70 [ 136.932623] [] compat_SyS_openat+0x2d/0x40 [ 136.938476] [] ? compat_SyS_open+0x40/0x40 [ 136.944334] [] do_fast_syscall_32+0x2f7/0x890 [ 136.950449] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 136.957087] [] entry_SYSENTER_compat+0x74/0x83 [ 136.963638] Dumping ftrace buffer: [ 136.967148] (ftrace buffer empty) [ 136.970830] Kernel Offset: disabled [ 136.974429] Rebooting in 86400 seconds..