Re: [PATCH v2] Add security.* XATTR support for the UBIFS

Subodh Nijsure
2012-04-11T13:00:49Z

On Tue, Apr 10, 2012 at 5:46 AM, Stephen Smalley <sds@tycho.nsa.gov> wrote:
> On Mon, 2012-04-09 at 16:51 -0700, subodh.nijsure@gmail.com wrote:
>> From: Subodh Nijsure <snijsure@grid-net.com>
>>
>> Also fix couple of bugs in UBIFS extended attribute length calculation.
>>
>> Changes Since V1:
>>          Instead of just handling security.selinux extended attribute handle
>>          all security.* attributes.
>>
>> TESTING: Tested on  MX28 based platforms using Micron MT29F2G08ABAEAH4 NAND
>>          With these change we are able to label UBIFS filesystem with
>>          security.selinux and run system with selinux enabled.
>>          This change also allows one to set other security.* extended
>>          attributesr, such as security.smack security.evm, security.ima
>>          Ran integck test on UBI filesystem.
>>
>> Signed-off-by: Subodh Nijsure <snijsure@grid-net.com>
>> ---
>>  fs/ubifs/dir.c     |    4 ++
>>  fs/ubifs/file.c    |    6 ++
>>  fs/ubifs/journal.c |   12 +++-
>>  fs/ubifs/super.c   |    3 +
>>  fs/ubifs/ubifs.h   |    9 +++
>>  fs/ubifs/xattr.c   |  147 ++++++++++++++++++++++++++++++++++++++++++++++++----
>>  6 files changed, 167 insertions(+), 14 deletions(-)
>>
>> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
>> index ec9f187..f4e06c4 100644
>> --- a/fs/ubifs/dir.c
>> +++ b/fs/ubifs/dir.c
>> @@ -293,6 +293,7 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
>>       ubifs_release_budget(c, &req);
>>       insert_inode_hash(inode);
>>       d_instantiate(dentry, inode);
>> +     ubifs_init_security(dir, inode, &dentry->d_name);
>>       return 0;
>>
>>  out_cancel:
>
> The ubifs_init_security() should occur before d_instantiate() so that
> the inode is not accessible to other threads before its security
> attributes have been set.  And if it fails, you would ideally drop the
> inode altogether and return an error to the creating process.
>

I will look into moving ubifs_init_security() before d_instantiate().
Last time I had tried I had run into some issues and had to keep
creating inode and then creating xattr as two seperate items. I will
look through the UBIFS code that actually creates xattr ubi nodes.
Also I will wait for couple of days to send v3 patch with to see if
mtd folks have other comments this patch.

Regards,
-Subodh