eCryptfs: Properly check for O_RDONLY flag before doing privileged open
authorTyler Hicks <tyhicks@canonical.com>
Tue, 12 Jun 2012 18:17:01 +0000 (11:17 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 16 Jul 2012 16:04:26 +0000 (09:04 -0700)
commitb6855f6d78cee5d72adc8f07be2646dd83c171c3
treeba67ce52faf0e783dc649f013a0a16fd83b16450
parentb6d7c70709e324e074d3a69249980bba1529fd01
eCryptfs: Properly check for O_RDONLY flag before doing privileged open

commit 9fe79d7600497ed8a95c3981cbe5b73ab98222f0 upstream.

If the first attempt at opening the lower file read/write fails,
eCryptfs will retry using a privileged kthread. However, the privileged
retry should not happen if the lower file's inode is read-only because a
read/write open will still be unsuccessful.

The check for determining if the open should be retried was intended to
be based on the access mode of the lower file's open flags being
O_RDONLY, but the check was incorrectly performed. This would cause the
open to be retried by the privileged kthread, resulting in a second
failed open of the lower file. This patch corrects the check to
determine if the open request should be handled by the privileged
kthread.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ecryptfs/kthread.c