Subject: Re: ktrace and P_SUGID
To: Simon J. Gerraty <sjg@crufty.net>
From: None <itojun@iijlab.net>
List: tech-security
Date: 06/29/2002 21:16:26
>> the following line takes care of "invoked by root" case.
>
>> if ((caller->pc_ucred->cr_uid == target->p_ruid &&
>> target->p_ruid == target->p_svuid &&
>> caller->p_rgid == target->p_rgid && /* XXX */
>> target->p_rgid == target->p_svgid &&
>> (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
>> (targetp->p_flag & P_SUGID) == 0) ||
>> caller->pc_ucred->cr_uid == 0) <----
>> return (1);
>Hmm, wouldn't it be better to test caller->pc_ucred->cr_uid == 0
>first?
it won't make that much of difference, as the first clause will not get
evaluated all the way through if any of the sub-clause fails.
for instance, if
caller->pc_ucred->cr_uid == target->p_ruid
is false, the rest won't get evaluated.
itojun