[....] Starting enhanced syslogd: rsyslogd[ 12.268591] audit: type=1400 audit(1515534194.628:5): avc: denied { syslog } for pid=3343 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: [ 16.622160] audit: type=1400 audit(1515534198.981:6): avc: denied { map } for pid=3482 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 '10.128.0.18' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 22.850613] audit: type=1400 audit(1515534205.210:7): avc: denied { map } for pid=3497 comm="syzkaller369142" path="/root/syzkaller369142330" 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 [ 22.972324] [ 22.972704] audit: type=1400 audit(1515534205.331:8): avc: denied { map } for pid=3497 comm="syzkaller369142" path="/dev/ashmem" dev="devtmpfs" ino=8894 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 22.998687] ====================================================== [ 23.004972] WARNING: possible circular locking dependency detected [ 23.011262] 4.15.0-rc7+ #255 Not tainted [ 23.015285] ------------------------------------------------------ [ 23.021581] syzkaller369142/3497 is trying to acquire lock: [ 23.027262] (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000cf5dc36e>] shmem_file_llseek+0xef/0x240 [ 23.036782] [ 23.036782] but task is already holding lock: [ 23.042714] (ashmem_mutex){+.+.}, at: [<00000000a81ce9c2>] ashmem_llseek+0x56/0x1f0 [ 23.050585] [ 23.050585] which lock already depends on the new lock. [ 23.050585] [ 23.058862] [ 23.058862] the existing dependency chain (in reverse order) is: [ 23.066444] [ 23.066444] -> #2 (ashmem_mutex){+.+.}: [ 23.071867] __mutex_lock+0x16f/0x1a80 [ 23.076240] mutex_lock_nested+0x16/0x20 [ 23.080785] ashmem_mmap+0x53/0x410 [ 23.084899] mmap_region+0xa99/0x15a0 [ 23.089184] do_mmap+0x6c0/0xe00 [ 23.093038] vm_mmap_pgoff+0x1de/0x280 [ 23.097412] SyS_mmap_pgoff+0x462/0x5f0 [ 23.101873] SyS_mmap+0x16/0x20 [ 23.105640] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.110876] [ 23.110876] -> #1 (&mm->mmap_sem){++++}: [ 23.116384] __might_fault+0x13a/0x1d0 [ 23.120762] _copy_to_user+0x2c/0xc0 [ 23.124963] filldir+0x1a7/0x320 [ 23.128814] dcache_readdir+0x12d/0x5e0 [ 23.133274] iterate_dir+0x1ca/0x530 [ 23.137473] SyS_getdents+0x225/0x450 [ 23.141758] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.147005] [ 23.147005] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 23.153740] lock_acquire+0x1d5/0x580 [ 23.158026] down_write+0x87/0x120 [ 23.162053] shmem_file_llseek+0xef/0x240 [ 23.166688] vfs_llseek+0xa2/0xd0 [ 23.170630] ashmem_llseek+0xe7/0x1f0 [ 23.174915] SyS_lseek+0xeb/0x170 [ 23.178855] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.184102] [ 23.184102] other info that might help us debug this: [ 23.184102] [ 23.192214] Chain exists of: [ 23.192214] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 23.192214] [ 23.203720] Possible unsafe locking scenario: [ 23.203720] [ 23.209740] CPU0 CPU1 [ 23.214371] ---- ---- [ 23.219000] lock(ashmem_mutex); [ 23.222417] lock(&mm->mmap_sem); [ 23.228438] lock(ashmem_mutex); [ 23.234371] lock(&sb->s_type->i_mutex_key#11); [ 23.239092] [ 23.239092] *** DEADLOCK *** [ 23.239092] [ 23.245115] 1 lock held by syzkaller369142/3497: [ 23.249833] #0: (ashmem_mutex){+.+.}, at: [<00000000a81ce9c2>] ashmem_llseek+0x56/0x1f0 [ 23.258118] [ 23.258118] stack backtrace: [ 23.262584] CPU: 0 PID: 3497 Comm: syzkaller369142 Not tainted 4.15.0-rc7+ #255 [ 23.269994] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.279313] Call Trace: [ 23.281875] dump_stack+0x194/0x257 [ 23.285468] ? arch_local_irq_restore+0x53/0x53 [ 23.290114] print_circular_bug.isra.37+0x2cd/0x2dc [ 23.295096] ? save_trace+0xe0/0x2b0 [ 23.298777] __lock_acquire+0x30a8/0x3e00 [ 23.302893] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 23.308057] ? ashmem_llseek+0x56/0x1f0 [ 23.311998] ? lock_release+0xa40/0xa40 [ 23.315939] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.321792] ? rcu_note_context_switch+0x710/0x710 [ 23.326689] ? vma_wants_writenotify+0x3b0/0x3b0 [ 23.331411] ? __might_sleep+0x95/0x190 [ 23.335349] ? ashmem_llseek+0x56/0x1f0 [ 23.339289] ? __mutex_lock+0x16f/0x1a80 [ 23.343314] ? ashmem_llseek+0x56/0x1f0 [ 23.347253] ? mmap_region+0x52e/0x15a0 [ 23.351206] ? ashmem_llseek+0x56/0x1f0 [ 23.355145] ? mutex_lock_io_nested+0x1900/0x1900 [ 23.359956] ? vm_mmap_pgoff+0x1ed/0x280 [ 23.363984] ? userfaultfd_unmap_complete+0x327/0x510 [ 23.369142] lock_acquire+0x1d5/0x580 [ 23.372907] ? lock_acquire+0x1d5/0x580 [ 23.376847] ? shmem_file_llseek+0xef/0x240 [ 23.381135] ? lock_release+0xa40/0xa40 [ 23.385077] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 23.390936] ? rcu_note_context_switch+0x710/0x710 [ 23.395830] ? __fget_light+0x297/0x380 [ 23.399770] ? __might_sleep+0x95/0x190 [ 23.403711] down_write+0x87/0x120 [ 23.407217] ? shmem_file_llseek+0xef/0x240 [ 23.411504] ? down_read+0x150/0x150 [ 23.415207] ? selinux_capable+0x40/0x40 [ 23.419239] shmem_file_llseek+0xef/0x240 [ 23.423354] ? shmem_free_swap+0x80/0x80 [ 23.427380] vfs_llseek+0xa2/0xd0 [ 23.430799] ashmem_llseek+0xe7/0x1f0 [ 23.434565] ? ashmem_read_iter+0x230/0x230 [ 23.438861] SyS_lseek+0xeb/0x170 [ 23.442296] entry_SYSCALL_64_fastpath+0x23/0x9a [ 23.447028] RIP: 0033:0x444aa9 [ 23.450184] RSP: 002b:00007fffd187fb08 EFLAGS: 00000217 ORIG_RAX: 0000000000000008 [ 23.457858] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000444aa9 [ 23.465103] RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000004 [ 23.472338] RBP: 00000