audit: type=1400 audit(1516102145.422:8): avc:  denied  { map } for  pid=3663 comm="syzkaller760307" path="/dev/ashmem" dev="devtmpfs" ino=8931 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1

======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc8+ #173 Not tainted
------------------------------------------------------
syzkaller760307/3663 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000322dbfd7>] inode_lock include/linux/fs.h:713 [inline]
 (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000322dbfd7>] shmem_file_llseek+0xef/0x240 mm/shmem.c:2579

but task is already holding lock:
 (ashmem_mutex){+.+.}, at: [<00000000b96c504d>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:334

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (ashmem_mutex){+.+.}: