[....] Starting enhanced syslogd: rsyslogd[ 12.536755] audit: type=1400 audit(1515534881.403:5): avc: denied { syslog } for pid=3342 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: [ 15.815795] audit: type=1400 audit(1515534884.682:6): avc: denied { map } for pid=3481 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 '10.128.15.194' (ECDSA) to the list of known hosts. net.ipv6.conf.syz0.accept_dad = 0 net.ipv6.conf.syz0.router_solicitations = 0 [ 21.979531] audit: type=1400 audit(1515534890.846:7): avc: denied { map } for pid=3495 comm="syzkaller244529" path="/root/syzkaller244529699" 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 [ 22.090116] [ 22.091132] audit: type=1400 audit(1515534890.956:8): avc: denied { map } for pid=3495 comm="syzkaller244529" path="/dev/ashmem" dev="devtmpfs" ino=8884 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 [ 22.116452] ====================================================== [ 22.122737] WARNING: possible circular locking dependency detected [ 22.129026] 4.15.0-rc7-next-20180109+ #92 Not tainted [ 22.134179] ------------------------------------------------------ [ 22.140464] syzkaller244529/3495 is trying to acquire lock: [ 22.146137] (&sb->s_type->i_mutex_key#11){++++}, at: [<000000006a910bd3>] shmem_file_llseek+0xef/0x240 [ 22.155646] [ 22.155646] but task is already holding lock: [ 22.161593] (ashmem_mutex){+.+.}, at: [<000000000ba826b5>] ashmem_llseek+0x56/0x1f0 [ 22.169449] [ 22.169449] which lock already depends on the new lock. [ 22.169449] [ 22.177726] [ 22.177726] the existing dependency chain (in reverse order) is: [ 22.185310] [ 22.185310] -> #2 (ashmem_mutex){+.+.}: [ 22.190735] __mutex_lock+0x16f/0x1a80 [ 22.195108] mutex_lock_nested+0x16/0x20 [ 22.199656] ashmem_mmap+0x53/0x410 [ 22.203768] mmap_region+0xa99/0x15a0 [ 22.208052] do_mmap+0x73c/0xf70 [ 22.211911] vm_mmap_pgoff+0x1de/0x280 [ 22.216291] SyS_mmap_pgoff+0x462/0x5f0 [ 22.220750] SyS_mmap+0x16/0x20 [ 22.224516] entry_SYSCALL_64_fastpath+0x23/0x9a [ 22.229754] [ 22.229754] -> #1 (&mm->mmap_sem){++++}: [ 22.235272] __might_fault+0x13a/0x1d0 [ 22.239648] _copy_to_user+0x2c/0xc0 [ 22.243853] filldir+0x1a7/0x320 [ 22.247705] dcache_readdir+0x12d/0x5e0 [ 22.252169] iterate_dir+0x1ca/0x530 [ 22.256367] SyS_getdents+0x225/0x450 [ 22.260652] entry_SYSCALL_64_fastpath+0x23/0x9a [ 22.265887] [ 22.265887] -> #0 (&sb->s_type->i_mutex_key#11){++++}: [ 22.272611] lock_acquire+0x1d5/0x580 [ 22.276897] down_write+0x87/0x120 [ 22.280923] shmem_file_llseek+0xef/0x240 [ 22.285556] vfs_llseek+0xa2/0xd0 [ 22.289495] ashmem_llseek+0xe7/0x1f0 [ 22.293782] SyS_lseek+0xeb/0x170 [ 22.297721] entry_SYSCALL_64_fastpath+0x23/0x9a [ 22.302970] [ 22.302970] other info that might help us debug this: [ 22.302970] [ 22.311076] Chain exists of: [ 22.311076] &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex [ 22.311076] [ 22.322577] Possible unsafe locking scenario: [ 22.322577] [ 22.328599] CPU0 CPU1 [ 22.333228] ---- ---- [ 22.337858] lock(ashmem_mutex); [ 22.341275] lock(&mm->mmap_sem); [ 22.347302] lock(ashmem_mutex); [ 22.353235] lock(&sb->s_type->i_mutex_key#11); [ 22.357954] [ 22.357954] *** DEADLOCK *** [ 22.357954] [ 22.363978] 1 lock held by syzkaller244529/3495: [ 22.368692] #0: (ashmem_mutex){+.+.}, at: [<000000000ba826b5>] ashmem_llseek+0x56/0x1f0 [ 22.376984] [ 22.376984] stack backtrace: [ 22.381446] CPU: 1 PID: 3495 Comm: syzkaller244529 Not tainted 4.15.0-rc7-next-20180109+ #92 [ 22.389984] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 22.399304] Call Trace: [ 22.401862] dump_stack+0x194/0x257 [ 22.405456] ? arch_local_irq_restore+0x53/0x53 [ 22.410098] print_circular_bug.isra.37+0x2cd/0x2dc [ 22.415077] ? save_trace+0xe0/0x2b0 [ 22.418755] __lock_acquire+0x30a8/0x3e00 [ 22.422866] ? lock_downgrade+0x980/0x980 [ 22.426979] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 22.431791] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 22.436946] ? ashmem_llseek+0x56/0x1f0 [ 22.440900] ? lock_release+0xa40/0xa40 [ 22.444855] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 22.450717] ? vma_set_page_prot+0x16b/0x230 [ 22.455093] ? rcu_note_context_switch+0x710/0x710 [ 22.459985] ? vma_wants_writenotify+0x3b0/0x3b0 [ 22.464722] ? __might_sleep+0x95/0x190 [ 22.468664] ? ashmem_llseek+0x56/0x1f0 [ 22.472605] ? __mutex_lock+0x16f/0x1a80 [ 22.476631] ? ashmem_llseek+0x56/0x1f0 [ 22.480578] ? ashmem_llseek+0x56/0x1f0 [ 22.484519] ? mutex_lock_io_nested+0x1900/0x1900 [ 22.489327] ? vm_mmap_pgoff+0x1ed/0x280 [ 22.493353] ? selinux_mmap_addr+0x1f/0xf0 [ 22.497555] ? userfaultfd_unmap_complete+0x327/0x510 [ 22.502714] ? get_unmapped_area+0x265/0x300 [ 22.507096] lock_acquire+0x1d5/0x580 [ 22.510862] ? lock_acquire+0x1d5/0x580 [ 22.514810] ? shmem_file_llseek+0xef/0x240 [ 22.519098] ? lock_release+0xa40/0xa40 [ 22.523040] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 22.528898] ? rcu_note_context_switch+0x710/0x710 [ 22.533792] ? __fget_light+0x297/0x380 [ 22.537731] ? __might_sleep+0x95/0x190 [ 22.541673] down_write+0x87/0x120 [ 22.545180] ? shmem_file_llseek+0xef/0x240 [ 22.549468] ? down_read+0x150/0x150 [ 22.553152] ? selinux_capable+0x40/0x40 [ 22.557178] shmem_file_llseek+0xef/0x240 [ 22.561294] ? shmem_free_swap+0x80/0x80 [ 22.565324] vfs_llseek+0xa2/0xd0 [ 22.568745] ashmem_llseek+0xe7/0x1f0 [ 22.572513] ? ashmem_read_iter+0x230/0x230 [ 22.576797] SyS_lseek+0xeb/0x170 [ 22.580219] entry_SYSCALL_64_fastpath+0x23/0x9a [ 22.584939] RIP: 0033:0x444aa9 [ 22.588094] RSP: 002b:00007fff54f064f8 EFLAGS: