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selinux: Re: [PATCH 1/2] selinux: remove dead code in type_attri

Re: [PATCH 1/2] selinux: remove dead code in type_attribute_bounds_av()

From: KaiGai Kohei <kaigai_at_nospam>
Date: Thu Jan 21 2010 - 06:00:15 GMT
To: Stephen Smalley <sds@tycho.nsa.gov>


(2010/01/20 22:33), Stephen Smalley wrote:
> $ make C=2 security/selinux/ss/services.o
> security/selinux/ss/services.c: In function ‘type_attribute_bounds_av’:
> security/selinux/ss/services.c:524: warning: unused variable ‘target’
> security/selinux/ss/services.c:520: warning: unused variable ‘lo_tcontext’

Sorry, it was fixed.



This patch removes dead code in type_attribute_bounds_av().

Due to the historical reason, the type boundary feature is delivered from hierarchical types in libsepol, it has supported boundary features both of subject type (domain; in most cases) and target type.

However, we don't have any actual use cases in bounded target types, and it tended to make conceptual confusion. So, this patch removes the dead code to apply boundary checks on the target types. I makes clear the TYPEBOUNDS restricts privileges of a certain domain bounded to any other domain.

 Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> -- security/selinux/ss/services.c | 43 +++------------------------------------ 1 files changed, 4 insertions(+), 39 deletions(-) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 3b42b15..4a2bf21 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -516,16 +516,14 @@ static void type_attribute_bounds_av(struct context *scontext, u16 tclass, struct av_decision *avd) { - struct context lo_scontext; - struct context lo_tcontext; - struct av_decision lo_avd; struct type_datum *source = policydb.type_val_to_struct[scontext->type - 1]; - struct type_datum *target - = policydb.type_val_to_struct[tcontext->type - 1]; - u32 masked = 0; if (source->bounds) { + struct context lo_scontext; + struct av_decision lo_avd; + u32 masked; + memset(&lo_avd, 0, sizeof(lo_avd)); memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); @@ -538,40 +536,7 @@ static void type_attribute_bounds_av(struct context *scontext, if ((lo_avd.allowed & avd->allowed) == avd->allowed) return; /* no masked permission */ masked = ~lo_avd.allowed & avd->allowed; - } - - if (target->bounds) { - memset(&lo_avd, 0, sizeof(lo_avd)); - - memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); - lo_tcontext.type = target->bounds; - - context_struct_compute_av(scontext, - &lo_tcontext, - tclass, - &lo_avd); - if ((lo_avd.allowed & avd->allowed) == avd->allowed) - return; /* no masked permission */ - masked = ~lo_avd.allowed & avd->allowed; - } - - if (source->bounds && target->bounds) { - memset(&lo_avd, 0, sizeof(lo_avd)); - /* - * lo_scontext and lo_tcontext are already - * set up. - */ - - context_struct_compute_av(&lo_scontext, - &lo_tcontext, - tclass, - &lo_avd); - if ((lo_avd.allowed & avd->allowed) == avd->allowed) - return; /* no masked permission */ - masked = ~lo_avd.allowed & avd->allowed; - } - if (masked) { /* mask violated permissions */ avd->allowed &= ~masked; -- OSS Platform Development Division, NEC KaiGai Kohei <kaigai@ak.jp.nec.com> -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message.