Reproducing b/37189798, 

Running "test_that 100.107.3.81 cheets_CTSHelper.stress.0"

cryptohome can not remove user data:
2017-04-17T10:32:21.373434-07:00 ERR cryptohomed[2328]: Failed to decrypt any keysets for 18fa109729123e2f088b1b22e0ca41e75225570b
2017-04-17T10:32:21.373440-07:00 ERR cryptohomed[2328]: Error, cryptohome must be re-created because of fatal error.
2017-04-17T10:32:21.887339-07:00 ERR cryptohomed[2328]: Fatal decryption error, but unable to remove cryptohome.

the test is stuck, in debug file:
04/17 10:33:02.586 DEBUG|    cros_interface:0058| sh -c /bin/df --output=source,target /home/user/18fa109729123e2f088b1b22e0ca41e75225570b
04/17 10:33:02.599 DEBUG|    cros_interface:0067|  > stdout=[Filesystem     Mounted on
/dev/mmcblk0p1 /home
], stderr=[]


Even after removing manually the directory, the test is in a infinite loop:
04/17 10:33:21.440 DEBUG|    cros_interface:0058| sh -c /bin/df --output=source,target /home/user/18fa109729123e2f088b1b22e0ca41e75225570b
04/17 10:33:21.453 DEBUG|    cros_interface:0067|  > stdout=[], stderr=[df: '/home/user/18fa109729123e2f088b1b22e0ca41e75225570b': No such file or directory
]

The test should find out something is wrong and fail.