Re: [PATCH -V1 09/22] vfs: Make acl_permission_check() work for richacls

Aneesh Kumar K.V
2014-05-01T15:39:35Z

Dave Chinner <david@fromorbit.com> writes:

> On Sun, Apr 27, 2014 at 09:44:40PM +0530, Aneesh Kumar K.V wrote:
>> From: Andreas Gruenbacher <agruen@kernel.org>
>>
>> Signed-off-by: Andreas Gruenbacher <agruen@kernel.org>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>> fs/namei.c | 13 +++++++++++++
>> 1 file changed, 13 insertions(+)
>>
>> diff --git a/fs/namei.c b/fs/namei.c
>> index 26b9a8212837..06474553c08d 100644
>> --- a/fs/namei.c
>> +++ b/fs/namei.c
>> @@ -284,6 +284,19 @@ static int acl_permission_check(struct inode *inode, int mask)
>> {
>> unsigned int mode = inode->i_mode;
>>
>> + if (IS_RICHACL(inode)) {
>> + int error = check_acl(inode, mask);
>> + if (error != -EAGAIN)
>> + return error;
>> + if (mask & (MAY_DELETE_SELF | MAY_TAKE_OWNERSHIP |
>> + MAY_CHMOD | MAY_SET_TIMES)) {
>> + /*
>> + * The file permission bit cannot grant these
>> + * permissions.
>> + */
>> + return -EACCES;
>> + }
>> + }
>> if (likely(uid_eq(current_fsuid(), inode->i_uid)))
>> mode >>= 6;
>> else {
>
> why does this take priority over a simple uid match? Some comments
> explaining this for people unfamiliar with richacls would be nice.
> Not to mention the commit message should also explain the change...
>

Richacl can have further limitation on file owner. Will add more
comments around the function.

-aneesh