Eric Paris <eparis@xxxxxxxxxx> writes:
>> > I was thinking about this and kept telling myself I was going to test v2
>> > before I ack/nak. Clearly we shouldn't for the dropping of SUID if the
>> > process didn't have permission to change the ATTR_SIZE.
>> >
>> > Acked-by: Eric Paris <eparis@xxxxxxxxxx>
>>
>> BTW, Do you know why doesn't security modules fix the handling of
>> do_truncate() (i.e. ATTR_MODE | ATTR_SIZE). And why doesn't it allow to
>> pass ATTR_FORCE for it?
>
> I'm not sure what you mean. I understood ATTR_FORCE to mean 'I am magic
> and get to override all security checks." Which is why nothing should
> ever be using ATTR_FORCE with things other than SUID.
>
> I guess we could somehow force logic into the LSM to make it only apply
> to SUID and friends but I'm not sure it buys us anything.
Yes, I think it's good way. Don't we want to do the following?
if (permission check of job)
return error;
if (do job at once)
return error;
But currently way is,
if (permission check of first part)
return error
if (do first part of job)
return error
if (permission check of second part)
return error
if (do second part of job)
return error
So, if second part was error, we may want to undo the job of first part
in theory. But, to undo is just hard and strange.
This is why I think ATTR_FORCE is good way. What do you think?
Thanks.
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
