tree d553ed49a104387f898bc93bc226821b83d49583
parent 60d65f1f07a7d81d3eb3b91fc13fca80f2fdbb12
author Tyler Hicks <tyhicks@canonical.com> 1339431851 -0700
committer Tyler Hicks <tyhicks@canonical.com> 1341607872 -0500

eCryptfs: Gracefully refuse miscdev file ops on inherited/passed files

File operations on /dev/ecryptfs would BUG() when the operations were
performed by processes other than the process that originally opened the
file. This could happen with open files inherited after fork() or file
descriptors passed through IPC mechanisms. Rather than calling BUG(), an
error code can be safely returned in most situations.

In ecryptfs_miscdev_release(), eCryptfs still needs to handle the
release even if the last file reference is being held by a process that
didn't originally open the file. ecryptfs_find_daemon_by_euid() will not
be successful, so a pointer to the daemon is stored in the file's
private_data. The private_data pointer is initialized when the miscdev
file is opened and only used when the file is released.

https://launchpad.net/bugs/994247

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>