[....] Starting enhanced syslogd: rsyslogd[ 12.648927] audit: type=1400 audit(1516564404.111:5): avc: denied { syslog } for pid=3514 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 19.160315] audit: type=1400 audit(1516564410.622:6): avc: denied { map } for pid=3654 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 '10.128.15.210' (ECDSA) to the list of known hosts. executing program [ 25.419263] audit: type=1400 audit(1516564416.882:7): avc: denied { map } for pid=3668 comm="syzkaller355824" path="/root/syzkaller355824047" 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 [ 25.421952] [ 25.445238] audit: type=1400 audit(1516564416.882:8): avc: denied { map } for pid=3668 comm="syzkaller355824" path="/dev/ashmem" dev="devtmpfs" ino=8917 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 25.446786] ====================================================== [ 25.446788] WARNING: possible circular locking dependency detected [ 25.446791] 4.15.0-rc8-mm1+ #59 Not tainted [ 25.446792] ------------------------------------------------------ [ 25.446795] syzkaller355824/3668 is trying to acquire lock: [ 25.446799] (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000ce41f54a>] shmem_file_llseek+0xef/0x240 [ 25.510069] [ 25.510069] but task is already holding lock: [ 25.516009] (ashmem_mutex){+.+.}, at: [<00000000202f9264>] ashmem_llseek+0x56/0x1f0 [ 25.523869] [ 25.523869] which lock already depends on the new lock. [ 25.523869] [ 25.532152] [ 25.532152] the existing dependency chain (in reverse order) is: [ 25.539738] [ 25.539738] -> #2 (ashmem_mutex){+.+.}: [ 25.545167] __mutex_lock+0x16f/0x1a80 [ 25.549546] mutex_lock_nested+0x16/0x20 [ 25.554095] ashmem_mmap+0x53/0x410 [ 25.558211] mmap_region+0xa99/0x15a0 [ 25.562498] do_mmap+0x73c/0xf70 [ 25.566356] vm_mmap_pgoff+0x1de/0x280 [ 25.570734] SyS_mmap_pgoff+0x462/0x5f0 [ 25.575198] SyS_mmap+0x16/0x20 [ 25.578976] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.584220] [ 25.584220] -> #1 (&mm->mmap_sem){++++}: [ 25.589736] __might_fault+0x13a/0x1d0 [ 25.594115] _copy_to_user+0x2c/0xc0 [ 25.598327] filldir+0x1a7/0x320 [ 25.602197] dcache_readdir+0x12d/0x5e0 [ 25.606663] iterate_dir+0x1ca/0x530 [ 25.610867] SyS_getdents+0x225/0x450 [ 25.615159] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.620400] [ 25.620400] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 25.627130] lock_acquire+0x1d5/0x580 [ 25.631420] down_write+0x87/0x120 [ 25.635451] shmem_file_llseek+0xef/0x240 [ 25.640087] vfs_llseek+0xa2/0xd0 [ 25.644028] ashmem_llseek+0xe7/0x1f0 [ 25.648320] SyS_lseek+0xeb/0x170 [ 25.652262] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.657503] [ 25.657503] other info that might help us debug this: [ 25.657503] [ 25.665612] Chain exists of: [ 25.665612] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 25.665612] [ 25.677122] Possible unsafe locking scenario: [ 25.677122] [ 25.683146] CPU0 CPU1 [ 25.687781] ---- ---- [ 25.692414] lock(ashmem_mutex); [ 25.695834] lock(&mm->mmap_sem); [ 25.701865] lock(ashmem_mutex); [ 25.707805] lock(&sb->s_type->i_mutex_key#11); [ 25.712532] [ 25.712532] *** DEADLOCK *** [ 25.712532] [ 25.718558] 1 lock held by syzkaller355824/3668: [ 25.723279] #0: (ashmem_mutex){+.+.}, at: [<00000000202f9264>] ashmem_llseek+0x56/0x1f0 [ 25.731668] [ 25.731668] stack backtrace: [ 25.736137] CPU: 1 PID: 3668 Comm: syzkaller355824 Not tainted 4.15.0-rc8-mm1+ #59 [ 25.743811] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.753134] Call Trace: [ 25.755695] dump_stack+0x194/0x257 [ 25.759293] ? arch_local_irq_restore+0x53/0x53 [ 25.763937] print_circular_bug.isra.38+0x2cd/0x2dc [ 25.768924] ? save_trace+0xe0/0x2b0 [ 25.772605] __lock_acquire+0x30a8/0x3e00 [ 25.776721] ? lock_downgrade+0x980/0x980 [ 25.780838] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 25.785660] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 25.790819] ? ashmem_llseek+0x56/0x1f0 [ 25.794764] ? lock_release+0xa40/0xa40 [ 25.798708] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.804560] ? vma_set_page_prot+0x16b/0x230 [ 25.808938] ? rcu_note_context_switch+0x710/0x710 [ 25.813837] ? vma_wants_writenotify+0x3b0/0x3b0 [ 25.818563] ? __might_sleep+0x95/0x190 [ 25.822505] ? ashmem_llseek+0x56/0x1f0 [ 25.826447] ? __mutex_lock+0x16f/0x1a80 [ 25.830475] ? ashmem_llseek+0x56/0x1f0 [ 25.834420] ? ashmem_llseek+0x56/0x1f0 [ 25.838365] ? mutex_lock_io_nested+0x1900/0x1900 [ 25.843180] ? selinux_mmap_addr+0x1f/0xf0 [ 25.847385] ? userfaultfd_unmap_complete+0x327/0x510 [ 25.852545] ? get_unmapped_area+0x265/0x300 [ 25.856925] lock_acquire+0x1d5/0x580 [ 25.860714] ? lock_acquire+0x1d5/0x580 [ 25.864659] ? shmem_file_llseek+0xef/0x240 [ 25.868950] ? lock_release+0xa40/0xa40 [ 25.872894] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 25.878748] ? rcu_note_context_switch+0x710/0x710 [ 25.883646] ? __fget_light+0x297/0x380 [ 25.887590] ? __might_sleep+0x95/0x190 [ 25.891541] down_write+0x87/0x120 [ 25.895059] ? shmem_file_llseek+0xef/0x240 [ 25.899347] ? down_read+0x150/0x150 [ 25.903029] ? selinux_capable+0x40/0x40 [ 25.907061] shmem_file_llseek+0xef/0x240 [ 25.911176] ? shmem_free_swap+0x80/0x80 [ 25.915204] vfs_llseek+0xa2/0xd0 [ 25.918628] ashmem_llseek+0xe7/0x1f0 [ 25.922397] ? ashmem_read_iter+0x230/0x230 [ 25.926687] SyS_lseek+0xeb/0x170 [ 25.930113] entry_SYSCALL_64_fastpath+0x29/0xa0 [ 25.934834] RIP: 0033:0x43fd19 [ 25.937992] RSP: 002b:00007fff8b60b448 EFLAGS: 00000217 ORIG_RAX: 0000000000000008 [ 25.945669] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd19 [ 25.952907] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000003 [ 25.960162] RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 [ 25.967402] R10: 0000000000000003 R11: 00000000