Re: [PULL] Smack: Restore the smackfsdef mount option
From: Casey Schaufler <casey@schaufler-ca.com>
Date: 2019-05-28 19:43:22
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On 5/28/2019 12:02 PM, David Howells wrote:
Casey Schaufler [off-list ref] wrote:quoted
James, this is a repair for a regression introduced in 5.1. It should be pulled for 5.2 and added to 5.1. The following changes since commit 619ae03e922b65a1a5d4269ceae1e9e13a058d6b: Smack: Fix kbuild reported build error (2019-04-30 14:13:32 -0700) are available in the git repository at: https://github.com/cschaufler/next-smack.git smack-for-5.2-b for you to fetch changes up to a5765ce797070d046dc53ccceeb0ed304cb918eb: Smack: Restore the smackfsdef mount option (2019-05-28 10:22:04 -0700)Can you hold this for the moment, please?
OK ...
Note that there appears to be another problem by inspection of the code. I
think that smack_sb_eat_lsm_opts() strips the "smack" prefix off of the
options, whereas smack_fs_context_parse_param() does not.
This means that there's no need to do this:
static const struct fs_parameter_spec smack_param_specs[] = {
+ fsparam_string("fsdef", Opt_fsdefault),
fsparam_string("fsdefault", Opt_fsdefault),
fsparam_string("fsfloor", Opt_fsfloor),
fsparam_string("fshat", Opt_fshat),
but that all the option names in that table *do* need prefixing with "smack".I'm not sure I follow the logic, because "mount -o smackfsdefault=Pop" does what I would expect it to.
The way you enter the LSM is going to depend on whether generic_parse_monolithic() is called. You're only going to enter this way if mount(2) is the syscall of entry and the filesystem doesn't override the ->parse_monolithic() option (none in the upstream kernel).
So you're saying that the code works for the mount(2) case, but won't work for some other case? Are you planning a fix? Will that fix include restoration of smackfsdef?
David