[....] Starting enhanced syslogd: rsyslogd[ 16.584302] audit: type=1400 audit(1518851483.620:5): avc: denied { syslog } for pid=3918 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: [ 22.280758] audit: type=1400 audit(1518851489.316:6): avc: denied { map } for pid=4056 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 '10.128.0.35' (ECDSA) to the list of known hosts. executing program [ 28.575202] audit: type=1400 audit(1518851495.611:7): avc: denied { map } for pid=4070 comm="syzkaller192186" path="/root/syzkaller192186295" 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 [ 28.578723] [ 28.601154] audit: type=1400 audit(1518851495.611:8): avc: denied { map } for pid=4070 comm="syzkaller192186" path="/dev/ashmem" dev="devtmpfs" ino=161 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 28.602705] ====================================================== [ 28.602707] WARNING: possible circular locking dependency detected [ 28.602712] 4.16.0-rc1+ #316 Not tainted [ 28.602714] ------------------------------------------------------ [ 28.602717] syzkaller192186/4070 is trying to acquire lock: [ 28.602719] (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000afc83883>] shmem_file_llseek+0xef/0x240 [ 28.665399] [ 28.665399] but task is already holding lock: [ 28.671337] (ashmem_mutex){+.+.}, at: [<000000009c52fe84>] ashmem_llseek+0x56/0x1f0 [ 28.679209] [ 28.679209] which lock already depends on the new lock. [ 28.679209] [ 28.687502] [ 28.687502] the existing dependency chain (in reverse order) is: [ 28.695096] [ 28.695096] -> #2 (ashmem_mutex){+.+.}: [ 28.700531] __mutex_lock+0x16f/0x1a80 [ 28.704911] mutex_lock_nested+0x16/0x20 [ 28.709462] ashmem_mmap+0x53/0x410 [ 28.713579] mmap_region+0xa99/0x15a0 [ 28.717868] do_mmap+0x6c0/0xe00 [ 28.721727] vm_mmap_pgoff+0x1de/0x280 [ 28.726103] SyS_mmap_pgoff+0x462/0x5f0 [ 28.730575] SyS_mmap+0x16/0x20 [ 28.734345] do_syscall_64+0x280/0x940 [ 28.738726] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 28.744406] [ 28.744406] -> #1 (&mm->mmap_sem){++++}: [ 28.749925] __might_fault+0x13a/0x1d0 [ 28.754308] _copy_to_user+0x2c/0xc0 [ 28.758512] filldir+0x1a7/0x320 [ 28.762370] dcache_readdir+0x12d/0x5e0 [ 28.766834] iterate_dir+0x1ca/0x530 [ 28.771044] SyS_getdents+0x225/0x450 [ 28.775340] do_syscall_64+0x280/0x940 [ 28.779721] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 28.785405] [ 28.785405] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 28.792139] lock_acquire+0x1d5/0x580 [ 28.796443] down_write+0x87/0x120 [ 28.800478] shmem_file_llseek+0xef/0x240 [ 28.805119] vfs_llseek+0xa2/0xd0 [ 28.809080] ashmem_llseek+0xe7/0x1f0 [ 28.813369] SyS_lseek+0xeb/0x170 [ 28.817661] do_syscall_64+0x280/0x940 [ 28.822039] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 28.827714] [ 28.827714] other info that might help us debug this: [ 28.827714] [ 28.835826] Chain exists of: [ 28.835826] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 28.835826] [ 28.847331] Possible unsafe locking scenario: [ 28.847331] [ 28.853359] CPU0 CPU1 [ 28.857993] ---- ---- [ 28.862630] lock(ashmem_mutex); [ 28.866054] lock(&mm->mmap_sem); [ 28.872084] lock(ashmem_mutex); [ 28.878029] lock(&sb->s_type->i_mutex_key#11); [ 28.882756] [ 28.882756] *** DEADLOCK *** [ 28.882756] [ 28.888784] 1 lock held by syzkaller192186/4070: [ 28.893516] #0: (ashmem_mutex){+.+.}, at: [<000000009c52fe84>] ashmem_llseek+0x56/0x1f0 [ 28.901830] [ 28.901830] stack backtrace: [ 28.906297] CPU: 1 PID: 4070 Comm: syzkaller192186 Not tainted 4.16.0-rc1+ #316 [ 28.913721] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.923057] Call Trace: [ 28.925622] dump_stack+0x194/0x257 [ 28.929222] ? arch_local_irq_restore+0x53/0x53 [ 28.933870] print_circular_bug.isra.38+0x2cd/0x2dc [ 28.938865] ? save_trace+0xe0/0x2b0 [ 28.942550] __lock_acquire+0x30a8/0x3e00 [ 28.946669] ? uprobe_mmap+0x15a/0xc90 [ 28.950533] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 28.955698] ? ashmem_llseek+0x56/0x1f0 [ 28.959645] ? lock_release+0xa40/0xa40 [ 28.963610] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 28.969469] ? rcu_note_context_switch+0x710/0x710 [ 28.974368] ? __might_sleep+0x95/0x190 [ 28.978315] ? ashmem_llseek+0x56/0x1f0 [ 28.982263] ? __mutex_lock+0x16f/0x1a80 [ 28.986301] ? ashmem_llseek+0x56/0x1f0 [ 28.990253] ? mmap_region+0x52e/0x15a0 [ 28.994201] ? ashmem_llseek+0x56/0x1f0 [ 28.998146] ? mutex_lock_io_nested+0x1900/0x1900 [ 29.002961] ? lock_downgrade+0x980/0x980 [ 29.007084] ? userfaultfd_unmap_complete+0x327/0x510 [ 29.012249] lock_acquire+0x1d5/0x580 [ 29.016022] ? lock_acquire+0x1d5/0x580 [ 29.019970] ? shmem_file_llseek+0xef/0x240 [ 29.024271] ? lock_release+0xa40/0xa40 [ 29.028216] ? trace_event_raw_event_sched_switch+0x810/0x810 [ 29.034074] ? rcu_note_context_switch+0x710/0x710 [ 29.038989] ? __fget_light+0x2b2/0x3c0 [ 29.042934] ? __might_sleep+0x95/0x190 [ 29.046879] down_write+0x87/0x120 [ 29.050398] ? shmem_file_llseek+0xef/0x240 [ 29.054688] ? down_read+0x150/0x150 [ 29.058387] shmem_file_llseek+0xef/0x240 [ 29.062526] ? shmem_free_swap+0x80/0x80 [ 29.066584] vfs_llseek+0xa2/0xd0 [ 29.070020] ashmem_llseek+0xe7/0x1f0 [ 29.073802] ? ashmem_read_iter+0x230/0x230 [ 29.078103] SyS_lseek+0xeb/0x170 [ 29.081532] ? vfs_clone_file_range+0x6b0/0x6b0 [ 29.086183] do_syscall_64+0x280/0x940 [ 29.090064] ? __do_page_fault+0xc90/0xc90 [ 29.094270] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.099027] ? syscall_return_slowpath+0x550/0x550 [ 29.103942] ? syscall_return_slowpath+0x2ac/0x550 [ 29.108849] ? prepare_exit_to_usermode+0x350/0x350 [ 29.113837] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 29.119172] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.123995] entry_SYSCALL_64_after_hwfram