[....] Starting enhanced syslogd: rsyslogd[ 13.186821] audit: type=1400 audit(1516632875.592:5): avc: denied { syslog } for pid=3504 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 syzkaller login: [ 17.551615] audit: type=1400 audit(1516632879.957:6): avc: denied { map } for pid=3644 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.15.198' (ECDSA) to the list of known hosts. executing program executing program executing program executing program [ 41.935807] audit: type=1400 audit(1516632904.341:7): avc: denied { map } for pid=3662 comm="syzkaller811670" path="/root/syzkaller811670736" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file 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 [ 45.927203] ================================================================== [ 45.938270] BUG: KASAN: use-after-free in __wake_up_common+0x670/0x780 [ 45.948172] Read of size 8 at addr ffff8801b6730ca0 by task syzkaller811670/4634 [ 45.959120] [ 45.961308] CPU: 1 PID: 4634 Comm: syzkaller811670 Not tainted 4.15.0-rc9+ #274 [ 45.972122] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.985912] Call Trace: [ 45.989818] dump_stack+0x194/0x257 [ 45.994855] ? arch_local_irq_restore+0x53/0x53 [ 46.001780] ? show_regs_print_info+0x18/0x18 [ 46.008348] ? rcu_segcblist_first_pend_cb+0x90/0x90 [ 46.015899] ? __wake_up_common+0x670/0x780 [ 46.022126] print_address_description+0x73/0x250 [ 46.029363] ? __wake_up_common+0x670/0x780 [ 46.035385] kasan_report+0x25b/0x340 [ 46.041143] __asan_report_load8_noabort+0x14/0x20 [ 46.048342] __wake_up_common+0x670/0x780 [ 46.054275] ? do_wait_intr_irq+0x3e0/0x3e0 [ 46.060965] ? lock_release+0xa40/0xa40 [ 46.066449] ? lock_downgrade+0x980/0x980 [ 46.072796] __wake_up_common_lock+0x1b4/0x310 [ 46.079447] ? locks_remove_file+0x3fa/0x5a0 [ 46.085917] ? __wake_up_common+0x780/0x780 [ 46.092205] ? fcntl_setlk+0x10c0/0x10c0 [ 46.098442] ? fsnotify_first_mark+0x2b0/0x2b0 [ 46.105124] ? eventfd_show_fdinfo+0x90/0x90 [ 46.111766] __wake_up+0xe/0x10 [ 46.116378] eventfd_release+0x4a/0x60 [ 46.122209] __fput+0x327/0x7e0 [ 46.127216] ? fput+0x140/0x140 [ 46.132036] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 46.140779] ? _raw_spin_unlock_irq+0x27/0x70 [ 46.147299] ____fput+0x15/0x20 [ 46.152119] task_work_run+0x199/0x270 [ 46.158080] ? task_work_cancel+0x210/0x210 [ 46.164097] ? _raw_spin_unlock+0x22/0x30 [ 46.170342] ? switch_task_namespaces+0x87/0xc0 [ 46.177291] do_exit+0x9bb/0x1ad0 [ 46.182305] ? mm_update_next_owner+0x930/0x930 [ 46.189357] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 46.196925] ? __might_sleep+0x95/0x190 [ 46.202773] ? find_held_lock+0x35/0x1d0 [ 46.208837] ? futex_wait+0x402/0x9a0 [ 46.214091] ? lock_downgrade+0x980/0x980 [ 46.220352] ? __unqueue_futex+0x1c0/0x290 [ 46.226351] ? lock_release+0xa40/0xa40 [ 46.232305] ? fault_in_user_writeable+0x90/0x90 [ 46.239445] ? do_raw_spin_trylock+0x190/0x190 [ 46.246380] ? futex_wake+0x680/0x680 [ 46.252122] ? check_noncircular+0x20/0x20 [ 46.258428] ? drop_futex_key_refs.isra.12+0x63/0xb0 [ 46.265923] ? futex_wait+0x6a9/0x9a0 [ 46.271402] ? find_held_lock+0x35/0x1d0 [ 46.277385] ? get_signal+0x7ae/0x16c0 [ 46.283050] ? lock_downgrade+0x980/0x980 [ 46.289281] do_group_exit+0x149/0x400 [ 46.294854] ? do_raw_spin_trylock+0x190/0x190 [ 46.301758] ? SyS_exit+0x30/0x30 [ 46.306930] ? _raw_spin_unlock_irq+0x27/0x70 [ 46.313218] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 46.321044] get_signal+0x73f/0x16c0 [ 46.326368] ? ptrace_notify+0x130/0x130 [ 46.332393] ? exit_robust_list+0x240/0x240 [ 46.339097] ? avc_has_extended_perms+0x7fa/0x12c0 [ 46.346260] ? find_held_lock+0x35/0x1d0 [ 46.352301] ? vhost_net_stop_vq+0xf0/0xf0 [ 46.358830] ? avc_ss_reset+0x110/0x110 [ 46.364261] ? lock_downgrade+0x980/0x980 [ 46.370786] do_signal+0x90/0x1eb0 [ 46.375896] ? __lock_is_held+0xb6/0x140 [ 46.381764] ? setup_sigcontext+0x7d0/0x7d0 [ 46.388179] ? rcu_note_context_switch+0x710/0x710 [ 46.395118] ? exit_to_usermode_loop+0x8c/0x310 [ 46.402122] exit_to_usermode_loop+0x214/0x310 [ 46.409270] ? ioctl_preallocate+0x2b0/0x2b0 [ 46.415891] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 46.424084] ? selinux_capable+0x40/0x40 [ 46.430247] syscall_return_slowpath+0x490/0x550 [ 46.437290] ? prepare_exit_to_usermode+0x340/0x340 [ 46.444440] ? entry_SYSCALL_64_fastpath+0x73/0xa0 [ 46.452207] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 46.459790] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 46.466932] entry_SYSCALL_64_fastpath+0x9e/0xa0 [ 46.473805] RIP: 0033:0x446849 [ 46.478813] RSP: 002b:00007fc40682eda8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 46.489954] RAX: fffffffffffffe00 RBX: 00000000006dcc24 RCX: 0000000000446849 [ 46.500763] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dcc24 [ 46.511120] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 46.522110] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc20 [ 46.532762] R13: 6f68762f7665642f R14: 00007fc40682f9c0 R15: 0000000000000007 [ 46.543227] [ 46.545888] Allocated by task 4634: [ 46.551211] save_stack+0x43/0xd0 [ 46.556334] kasan_kmalloc+0xad/0xe0 [ 46.562022] __kmalloc_node+0x47/0x70 [ 46.567889] kvmalloc_node+0x64/0xd0 [ 46.573034] vhost_net_open+0x27/0x670 [ 46.579010] misc_open+0x382/0x500 [ 46.584078] chrdev_open+0x257/0x730 [ 46.589785] do_dentry_open+0x667/0xd40 [ 46.595183] vfs_open+0x107/0x220 [ 46.600403] path_openat+0x1151/0x3530 [ 46.605899] do_filp_open+0x25b/0x3b0 [ 46.611374] do_sys_open+0x502/0x6d0 [ 46.616920] SyS_openat+0x30/0x40 [ 46.621941] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 46.629087] [ 46.631282] Freed by task 4634: [ 46.636082] save_stack+0x43/0xd0 [ 46.641207] kasan_slab_free+0x71/0xc0 [ 46.646918] kfree+0xd6/0x260 [ 46.651286] kvfree+0x36/0x60 [ 46.655893] vhost_net_release+0x159/0x190 [ 46.662188] __fput+0x327/0x7e0 [ 46.667183] ____fput+0x15/0x20 [ 46.672015] task_work_run+0x199/0x270 [ 46.678068] do_exit+0x9bb/0x1ad0 [ 46.682946] do_group_exit+0x149/0x400 [ 46.688813] get_signal+0x73f/0x16c0 [ 46.694081] do_signal+0x90/0x1eb0 [ 46.699432] exit_to_usermode_loop+0x214/0x310 [ 46.706249] syscall_return_slowpath+0x490/0x550 [ 46.713150] entry_SYSCALL_64_fastpath+0x9e/0xa0 [ 46.720314] [ 46.722751] The buggy address belongs to the object at ffff8801b672c3c0 [ 46.722751] which belongs to the cache kmalloc-65536 of size 65536 [ 46.742019] The buggy address is located 18656 bytes inside of [ 46.742019] 65536-byte region [ffff8801b672c3c0, ffff8801b673c3c0) [ 46.760308] The buggy address belongs to the page: [ 46.767872] page:ffffea0006d9c800 count:1 mapcount:0 mapping:ffff8801b672c3c0 index:0x0 compound_mapcount: 0 [ 46.782266] flags: 0x2fffc0000008100(slab|head) [ 46.789338] raw: 02fffc0000008100 ffff8801b672c3c0 0000000000000000 0000000100000001 [ 46.802200] raw: ffffea0006d9c020 ffffea0006d9d020 ffff8801dac02500 0000000000000000 [ 46.814164] page dumped because: kasan: bad access detected [ 46.822787] [ 46.825004] Memory state around the buggy address: [ 46.832265] ffff8801b6730b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.843200] ffff8801b6730c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.854153] >ffff8801b6730c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.865100] ^ [ 46.871735] ffff8801b6730d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.882346] ffff8801b6730d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 46.893107] ================================================================== [ 46.903984] Disabling lock debugging due to kernel taint [ 46.912178] Kernel panic - not syncing: panic_on_warn set ... [ 46.912178] [ 46.923021] CPU: 1 PID: 4634 Comm: syzkaller811670 Tainted: G B 4.15.0-rc9+ #274 [ 46.935880] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.949767] Call Trace: [ 46.953114] dump_stack+0x194/0x257 [ 46.958801] ? arch_local_irq_restore+0x53/0x53 [ 46.965266] ? kasan_end_report+0x32/0x50 [ 46.971735] ? lock_downgrade+0x980/0x980 [ 46.977866] ? vsnprintf+0x1ed/0x1900 [ 46.983028] ? __wake_up_common+0x670/0x780 [ 46.989425] panic+0x1e4/0x41c [ 46.994147] ? refcount_error_report+0x214/0x214 [ 47.001280] ? add_taint+0x40/0x50 [ 47.006404] ? add_taint+0x1c/0x50 [ 47.011733] ? __wake_up_common+0x670/0x780 [ 47.018130] kasan_end_report+0x50/0x50 [ 47.023789] kasan_report+0x144/0x340 [ 47.029419] __asan_report_load8_noabort+0x14/0x20 [ 47.036897] __wake_up_common+0x670/0x780 [ 47.042748] ? do_wait_intr_irq+0x3e0/0x3e0 [ 47.049150] ? lock_release+0xa40/0xa40 [ 47.054806] ? lock_downgrade+0x980/0x980 [ 47.061011] __wake_up_common_lock+0x1b4/0x310 [ 47.067862] ? locks_remove_file+0x3fa/0x5a0 [ 47.073965] ? __wake_up_common+0x780/0x780 [ 47.080394] ? fcntl_setlk+0x10c0/0x10c0 [ 47.086151] ? fsnotify_first_mark+0x2b0/0x2b0 [ 47.092933] ? eventfd_show_fdinfo+0x90/0x90 [ 47.099753] __wake_up+0xe/0x10 [ 47.104231] eventfd_release+0x4a/0x60 [ 47.110757] __fput+0x327/0x7e0 [ 47.115263] ? fput+0x140/0x140 [ 47.120300] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 47.129241] ? _raw_spin_unlock_irq+0x27/0x70 [ 47.135879] ____fput+0x15/0x20 [ 47.140747] task_work_run+0x199/0x270 [ 47.146143] ? task_work_cancel+0x210/0x210 [ 47.152730] ? _raw_spin_unlock+0x22/0x30 [ 47.158977] ? switch_task_namespaces+0x87/0xc0 [ 47.165860] do_exit+0x9bb/0x1ad0 [ 47.170922] ? mm_update_next_owner+0x930/0x930 [ 47.177859] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 47.185085] ? __might_sleep+0x95/0x190 [ 47.191095] ? find_held_lock+0x35/0x1d0 [ 47.197081] ? futex_wait+0x402/0x9a0 [ 47.202725] ? lock_downgrade+0x980/0x980 [ 47.208978] ? __unqueue_futex+0x1c0/0x290 [ 47.214990] ? lock_release+0xa40/0xa40 [ 47.221004] ? fault_in_user_writeable+0x90/0x90 [ 47.228035] ? do_raw_spin_trylock+0x190/0x190 [ 47.234403] ? futex_wake+0x680/0x680 [ 47.240381] ? check_noncircular+0x20/0x20 [ 47.246405] ? drop_futex_key_refs.isra.12+0x63/0xb0 [ 47.254059] ? futex_wait+0x6a9/0x9a0 [ 47.259953] ? find_held_lock+0x35/0x1d0 [ 47.265875] ? get_signal+0x7ae/0x16c0 [ 47.271722] ? lock_downgrade+0x980/0x980 [ 47.278041] do_group_exit+0x149/0x400 [ 47.283352] ? do_raw_spin_trylock+0x190/0x190 [ 47.290292] ? SyS_exit+0x30/0x30 [ 47.295161] ? _raw_spin_unlock_irq+0x27/0x70 [ 47.301990] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 47.309409] get_signal+0x73f/0x16c0 [ 47.314826] ? ptrace_notify+0x130/0x130 [ 47.320917] ? exit_robust_list+0x240/0x240 [ 47.327159] ? avc_has_extended_perms+0x7fa/0x12c0 [ 47.334216] ? find_held_lock+0x35/0x1d0 [ 47.340377] ? vhost_net_stop_vq+0xf0/0xf0 [ 47.346321] ? avc_ss_reset+0x110/0x110 [ 47.352249] ? lock_downgrade+0x980/0x980 [ 47.358788] do_signal+0x90/0x1eb0 [ 47.363778] ? __lock_is_held+0xb6/0x140 [ 47.369760] ? setup_sigcontext+0x7d0/0x7d0 [ 47.375877] ? rcu_note_context_switch+0x710/0x710 [ 47.383098] ? exit_to_usermode_loop+0x8c/0x310 [ 47.390118] exit_to_usermode_loop+0x214/0x310 [ 47.396887] ? ioctl_preallocate+0x2b0/0x2b0 [ 47.403179] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 47.411355] ? selinux_capable+0x40/0x40 [ 47.417341] syscall_return_slowpath+0x490/0x550 [ 47.424132] ? prepare_exit_to_usermode+0x340/0x340 [ 47.431716] ? entry_SYSCALL_64_fastpath+0x73/0xa0 [ 47.439057] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 47.446219] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 47.453185] entry_SYSCALL_64_fastpath+0x9e/0xa0 [ 47.460293] RIP: 0033:0x446849 [ 47.464977] RSP: 002b:00007fc40682eda8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 47.476305] RAX: fffffffffffffe00 RBX: 00000000006dcc24 RCX: 0000000000446849 [ 47.487322] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dcc24 [ 47.498022] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 47.507846] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc20 [ 47.515107] R13: 6f68762f7665642f R14: 00007fc40682f9c0 R15: 0000000000000007 [ 47.523107] Dumping ftrace buffer: [ 47.526626] (ftrace buffer empty) [ 47.530311] Kernel Offset: disabled [ 47.533911] Rebooting in 86400 seconds..