[apparmor] [PATCH 09/20] add helper fn to query file path permissions

[Tyler Hicks]

On 2015-05-30 00:00:25, Christian Boltz wrote:
> Hello,
> 
> Am Freitag, 29. Mai 2015 schrieb Tyler Hicks:
> > On 2015-05-29 01:39:15, John Johansen wrote:
> 
> > > +int aa_query_file(uint32_t mask, const char *label, const char
> > > *path, +		  int *allowed, int *audited)
> > 
> > I prefer that we require 'size_t label_len' and 'size_t path_len'
> > parameters. The caller may already have the string lengths stored in
> > variables, eliminating unnecessary calls to strlen(). Also, it allows
> > for non-nul-terminated strings to be used.
> 
> You mean you want to call the function with path "foo\0" and path_len 
> 12345?
> 
> Personally, I prefer an unnecessary strlen() call over an option to 
> allow someone to hand in invalid data (and, caused by that, possibly 
> doing funny[tm] things) ;-)

You may not be aware that strlen() requires the string to be
nul-terminated. If they wanted to shoot themselves in the foot or "do
funny things" they could just pass in a non nul-terminated string to
aa_query_file().

Also, libapparmor is in the process' address space. It makes no
difference if we allow the caller to specify the string length or not...

Tyler

> 
> 
> Regards,
> 
> Christian Boltz
> -- 
> Eine Katze hat einen Schwanz mehr als keine Katze. Keine Katze hat
> zwei Schwänze, also hat eine Katze drei Schwänze.
> [Bernd Brodesser in suse-linux]
> 
> 
> -- 
> AppArmor mailing list
> AppArmor at lists.ubuntu.com
> Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/apparmor
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <https://lists.ubuntu.com/archives/apparmor/attachments/20150529/b9cac71c/attachment.pgp>