mlock(2) and munlock(2) operate on memory pages whereas malloc(3)
does not. So if you munlock(2) a malloced memory region, the whole
page containing it is freed. Since this page may contain another
malloced and mlocked memory region, used as a password buffer by a
concurrent running instance of pam_zfs_key, there is a slight chance
of leaking passwords. By using mmap(2) we avoid such problems since
it will return whole pages on page aligned addresses.
Although the above concern may be mostly academical, it is still
better to use mmap(2) for allocating memory since the FreeBSD
documentation suggests to call mlock(2) and munlock(2) on page
aligned addresses, and other implementations even require it.
While here, remove duplicate code in alloc_pw_string() by calling
alloc_pw_size().
Reviewed-by: Felix Dörre <felix@dogcraft.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#12665
Since both syscalls can fail, add error handling, including EAGAIN.
Reviewed-by: Felix Dörre <felix@dogcraft.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#12665
Compiling with gcc 11.1.0 produces three new warnings.
Change the code slightly to avoid them.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#12130Closes#12188Closes#12237
Name of dataset for user home directory may vary from the expected
$homes_prefix/$username, if different naming scheme is being used.
We can use property mountpoint to specify the dataset for $username
as long as its value is identical to passwd's pw_dir.
For example:
NAME PROPERTY VALUE
rpool/home/myuser_123456 mountpoint /home/myuser
Reviewed-by: Felix Dörre <felix@dogcraft.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Crag Wang <crag0715@gmail.com>
Closes#11165
Implements a pam module for automatically loading zfs encryption keys
for home datasets. The pam module:
- loads a zfs key and mounts the dataset when a session opens.
- unmounts the dataset and unloads the key when the session closes.
- when the user is logged on and changes the password, the module
changes the encryption key.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: @jengelh <jengelh@inai.de>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Felix Dörre <felix@dogcraft.de>
Closes#9886Closes#9903
